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more thoughts on PET versus glass permeability
Following from a previous thread on PET versus glass, I observe that
the concensus seems on the whole to be thus: Glass is better than PET for long term storage, because PET is felt to be more permeable to oxygen than PET. If that sums things up correctly, I would like to ask about the following consideration: Is it not the case that rubber is hundreds of times more permeable than either, and thus the degree to which a long-term storage wine oxidizes in the carboy is really not significantly altered by the vessel, since most of the permeation of O2 is going to occur through the rubber? Your thoughts? Sean |
more thoughts on PET versus glass permeability
> > Is it not the case that rubber is hundreds of times more permeable than > either, and thus the degree to which a long-term storage wine oxidizes > in the carboy is really not significantly altered by the vessel, since > most of the permeation of O2 is going to occur through the rubber? I don't recall seeing any study that would confirm your assertion. If it is true, though... regard the surface area where the permeability would occur. 3-4 square inches at a bung, or massively more over the surface area of a carboy. Kirk |
more thoughts on PET versus glass permeability
Fair point, but I suppose it depends on the ratio. I have emailed better-bottle to see if they have any more specific
stats for internal carboy surface area and 02 exchange across the PET material. I can't help thinking that if the PET walls truly do suffer only 'negligible' 02 permeability, by definition they are as low risk as using a rubber bung (which probably has greater permeability but lower surface area). Interesting thread though :) Jim "Kirk Mitchell" > wrote in message oups.com... > > >> >> Is it not the case that rubber is hundreds of times more permeable than >> either, and thus the degree to which a long-term storage wine oxidizes >> in the carboy is really not significantly altered by the vessel, since >> most of the permeation of O2 is going to occur through the rubber? > > I don't recall seeing any study that would confirm your assertion. > > If it is true, though... regard the surface area where the permeability > would occur. 3-4 square inches at a bung, or massively more over the > surface area of a carboy. > > Kirk > |
more thoughts on PET versus glass permeability
About as much permeability as a barrel? Less I think.
On Sun, 7 Jan 2007 15:37:49 -0000, "jim" > wrote: >Fair point, but I suppose it depends on the ratio. I have emailed better-bottle to see if they have any more specific >stats for internal carboy surface area and 02 exchange across the PET material. > >I can't help thinking that if the PET walls truly do suffer only 'negligible' 02 permeability, by definition they are as >low risk as using a rubber bung (which probably has greater permeability but lower surface area). Interesting thread >though :) > >Jim > > >"Kirk Mitchell" > wrote in message oups.com... >> >> >>> >>> Is it not the case that rubber is hundreds of times more permeable than >>> either, and thus the degree to which a long-term storage wine oxidizes >>> in the carboy is really not significantly altered by the vessel, since >>> most of the permeation of O2 is going to occur through the rubber? >> >> I don't recall seeing any study that would confirm your assertion. >> >> If it is true, though... regard the surface area where the permeability >> would occur. 3-4 square inches at a bung, or massively more over the >> surface area of a carboy. >> >> Kirk >> > The Anchorage Fishwrapper and Litterbox Liner Press |
more thoughts on PET versus glass permeability
I hadn't even considered the permeability of barrels, good point :)
"A. J. Rawls" > wrote in message ... > About as much permeability as a barrel? Less I think. > > > On Sun, 7 Jan 2007 15:37:49 -0000, "jim" > > wrote: > >>Fair point, but I suppose it depends on the ratio. I have emailed better-bottle to see if they have any more specific >>stats for internal carboy surface area and 02 exchange across the PET material. >> >>I can't help thinking that if the PET walls truly do suffer only 'negligible' 02 permeability, by definition they are >>as >>low risk as using a rubber bung (which probably has greater permeability but lower surface area). Interesting thread >>though :) >> >>Jim >> >> >>"Kirk Mitchell" > wrote in message groups.com... >>> >>> >>>> >>>> Is it not the case that rubber is hundreds of times more permeable than >>>> either, and thus the degree to which a long-term storage wine oxidizes >>>> in the carboy is really not significantly altered by the vessel, since >>>> most of the permeation of O2 is going to occur through the rubber? >>> >>> I don't recall seeing any study that would confirm your assertion. >>> >>> If it is true, though... regard the surface area where the permeability >>> would occur. 3-4 square inches at a bung, or massively more over the >>> surface area of a carboy. >>> >>> Kirk >>> >> > The Anchorage Fishwrapper and Litterbox Liner Press |
more thoughts on PET versus glass permeability
yes thats really an excellent point...surely barrels are much much more
permeable than glass? A. J. Rawls wrote: > About as much permeability as a barrel? Less I think. > > > On Sun, 7 Jan 2007 15:37:49 -0000, "jim" > > wrote: > > >Fair point, but I suppose it depends on the ratio. I have emailed better-bottle to see if they have any more specific > >stats for internal carboy surface area and 02 exchange across the PET material. > > > >I can't help thinking that if the PET walls truly do suffer only 'negligible' 02 permeability, by definition they are as > >low risk as using a rubber bung (which probably has greater permeability but lower surface area). Interesting thread > >though :) > > > >Jim > > > > > >"Kirk Mitchell" > wrote in message oups.com... > >> > >> > >>> > >>> Is it not the case that rubber is hundreds of times more permeable than > >>> either, and thus the degree to which a long-term storage wine oxidizes > >>> in the carboy is really not significantly altered by the vessel, since > >>> most of the permeation of O2 is going to occur through the rubber? > >> > >> I don't recall seeing any study that would confirm your assertion. > >> > >> If it is true, though... regard the surface area where the permeability > >> would occur. 3-4 square inches at a bung, or massively more over the > >> surface area of a carboy. > >> > >> Kirk > >> > > > The Anchorage Fishwrapper and Litterbox Liner Press |
more thoughts on PET versus glass permeability
Actually it's more complicated than that for a sealed barrel. The
barrel is semi permeable and it is now thought that it actually pulls ambient air into the wine in tiny amounts because a vacuum is created on tightly bunged barrels. They consider this micro oxygenation and it's good for reds. As to whether a better bottle would emulate that, I guess it comes down to surface area and permeability. To be honest, I don't know if they think the air comes in from toppings or through the staves; I have seen both stated. Smaller containers have more surface to mass ratios, if you wanted to emulate anything i would guess the 30 to 55 gallon barrels would be the ones to go for. Maybe Google micro oxygenation and wine or barrels. Joe |
more thoughts on PET versus glass permeability
Yes, I thought the surface area to volume ratio would be a big influence on how much the stored wine is affected and
that is another point well raised! However, if Better Bottles really do have negligible permeability to O2 then they are likely to cause less sealed storage oxidation than a hypothetical barrel of of similar internal capacity or larger. I draw this conclusion because barrels don't have negligible permeability. I wondered if the following extract is useful? "Oak barriques soften wine by diffusing 20 to 30 mg. (15 to 23 ml.) of air-oxygen per litre of wine per year (mg/l/yr) through their micro-porous staves. This natural osmotic permeation is driven by the higher partial pressure of oxygen outside (0.2 atm) to inside the barrel (~zero), as wine "consumes" all the available oxygen that diffuses in. Permeation provides MOST of the oxygen entry into a barrel. Repeated topping only adds about 5 mg/l/yr and splashing/racking about 4 mg/litre each time. Successful wine maturation requires an "oxygen rationed" environment, rather than "all at once" oxygen exposure, which instead promotes oxygen catalyzed acetaldehyde formation and aerobic bacterial spoilage i.e. by Acetobacter, always present in small populations in wine (unless sterile filtered). Smaller barrels allow oxygen to diffuse in at a faster rate per litre of wine in them than larger barrels, due to their higher surface area to contained volume. Metal tanks allow no permeation, instead requiring micro-oxygenation. 4mm thickness of the special C-P polyethylene used in these vessels, diffuses oxygen from the air at about the same rate as 20mm of new Oak. However it is a one way effect. The C-P material is absolutely taint-free and does not allow evaporative loss of wine components so these vessels DO NOT NEED TOPPING." This quote comes from a metal fermentation container manufacturer so you could expect a bias in that direction. This is page though has some useful information on oxidation at several stages in different containers though - I don't know if it is contentious. http://www.flextank.com.au/Barrels.htm Food for thought all of it, Jim "Joe Sallustio" > wrote in message ups.com... > Actually it's more complicated than that for a sealed barrel. The > barrel is semi permeable and it is now thought that it actually pulls > ambient air into the wine in tiny amounts because a vacuum is created > on tightly bunged barrels. They consider this micro oxygenation and > it's good for reds. As to whether a better bottle would emulate > that, I guess it comes down to surface area and permeability. To be > honest, I don't know if they think the air comes in from toppings or > through the staves; I have seen both stated. Smaller containers have > more surface to mass ratios, if you wanted to emulate anything i would > guess the 30 to 55 gallon barrels would be the ones to go for. Maybe > Google micro oxygenation and wine or barrels. > > Joe > |
more thoughts on PET versus glass permeability
The conclusion from this and other posts seems to be that a Better
Bottle may or may not be permeable to oxygen, but even if it is, it doesn't matter because, as it turns out, a little oxygen is good anyway. Ergo, a Better Bottle may be the way to go :-) Joe Sallustio wrote: > Actually it's more complicated than that for a sealed barrel. The > barrel is semi permeable and it is now thought that it actually pulls > ambient air into the wine in tiny amounts because a vacuum is created > on tightly bunged barrels. They consider this micro oxygenation and > it's good for reds. As to whether a better bottle would emulate > that, I guess it comes down to surface area and permeability. To be > honest, I don't know if they think the air comes in from toppings or > through the staves; I have seen both stated. Smaller containers have > more surface to mass ratios, if you wanted to emulate anything i would > guess the 30 to 55 gallon barrels would be the ones to go for. Maybe > Google micro oxygenation and wine or barrels. > > Joe > |
more thoughts on PET versus glass permeability
Am I the only one who finds it a little odd that there is no obvious
evidence-based practice with this? RomeoMike wrote: > The conclusion from this and other posts seems to be that a Better > Bottle may or may not be permeable to oxygen, but even if it is, it > doesn't matter because, as it turns out, a little oxygen is good anyway. > Ergo, a Better Bottle may be the way to go :-) > > Joe Sallustio wrote: > > Actually it's more complicated than that for a sealed barrel. The > > barrel is semi permeable and it is now thought that it actually pulls > > ambient air into the wine in tiny amounts because a vacuum is created > > on tightly bunged barrels. They consider this micro oxygenation and > > it's good for reds. As to whether a better bottle would emulate > > that, I guess it comes down to surface area and permeability. To be > > honest, I don't know if they think the air comes in from toppings or > > through the staves; I have seen both stated. Smaller containers have > > more surface to mass ratios, if you wanted to emulate anything i would > > guess the 30 to 55 gallon barrels would be the ones to go for. Maybe > > Google micro oxygenation and wine or barrels. > > > > Joe > > |
more thoughts on PET versus glass permeability
Isn't this a pretty new product? I don't remember seeing ads for them
before 2 years or so. That's not enough time to get any decent aging data. Pp On Jan 8, 9:54 am, "snpm" > wrote: > Am I the only one who finds it a little odd that there is no obvious > evidence-based practice with this? > > > > RomeoMike wrote: > > The conclusion from this and other posts seems to be that a Better > > Bottle may or may not be permeable to oxygen, but even if it is, it > > doesn't matter because, as it turns out, a little oxygen is good anyway. > > Ergo, a Better Bottle may be the way to go :-) > > > Joe Sallustio wrote: > > > Actually it's more complicated than that for a sealed barrel. The > > > barrel is semi permeable and it is now thought that it actually pulls > > > ambient air into the wine in tiny amounts because a vacuum is created > > > on tightly bunged barrels. They consider this micro oxygenation and > > > it's good for reds. As to whether a better bottle would emulate > > > that, I guess it comes down to surface area and permeability. To be > > > honest, I don't know if they think the air comes in from toppings or > > > through the staves; I have seen both stated. Smaller containers have > > > more surface to mass ratios, if you wanted to emulate anything i would > > > guess the 30 to 55 gallon barrels would be the ones to go for. Maybe > > > Google micro oxygenation and wine or barrels. > > > > Joe- Hide quoted text -- Show quoted text - |
more thoughts on PET versus glass permeability
Their website will have been registered 4 years in April it seems.
Jim "pp" > wrote in message oups.com... > Isn't this a pretty new product? I don't remember seeing ads for them > before 2 years or so. That's not enough time to get any decent aging > data. > > Pp > > On Jan 8, 9:54 am, "snpm" > wrote: >> Am I the only one who finds it a little odd that there is no obvious >> evidence-based practice with this? >> >> >> >> RomeoMike wrote: >> > The conclusion from this and other posts seems to be that a Better >> > Bottle may or may not be permeable to oxygen, but even if it is, it >> > doesn't matter because, as it turns out, a little oxygen is good anyway. >> > Ergo, a Better Bottle may be the way to go :-) >> >> > Joe Sallustio wrote: >> > > Actually it's more complicated than that for a sealed barrel. The >> > > barrel is semi permeable and it is now thought that it actually pulls >> > > ambient air into the wine in tiny amounts because a vacuum is created >> > > on tightly bunged barrels. They consider this micro oxygenation and >> > > it's good for reds. As to whether a better bottle would emulate >> > > that, I guess it comes down to surface area and permeability. To be >> > > honest, I don't know if they think the air comes in from toppings or >> > > through the staves; I have seen both stated. Smaller containers have >> > > more surface to mass ratios, if you wanted to emulate anything i would >> > > guess the 30 to 55 gallon barrels would be the ones to go for. Maybe >> > > Google micro oxygenation and wine or barrels. >> >> > > Joe- Hide quoted text -- Show quoted text - > |
more thoughts on PET versus glass permeability
I don't know if this is of general interest, but here is the reply I had back from better bottle regarding permeability
and oxidation. I must say it sounds fair... " Substantial, and rapidly growing, numbers of home winemakers and brewers, as well as suppliers of kits, clearly prefer Better-Bottle's unique PET carboys and fittings to glass carboys. Nevertheless, anecdotal reports of oxygen diffusing through the walls of Better-Bottle carboys and causing poor results pop up from time to time and we are asked to comment. Making a good wine or beer is something of an art and occasionally results do not meet expectations, regardless of whether the winemaker or brewer uses a glass carboy or Better-Bottle carboy. It is impossible to draw any valid conclusions from anecdotal reports of sporadic, subtle failures, because identifying the cause rigorously is usually impractical. Absolutely, using carboys made from any of the common plastics that scalp flavors and are quite permeable to oxygen will guarantee an inferior result. However, it would be a mistake to assume that using a glass carboy will necessarily guarantee a superior result. Rubber stoppers, especially silicone stoppers, most common types of flexible tubing, and liquid-filled air locks can leak lots of oxygen. Moreover, oxygen diffuses so quickly through beer and wine that removing a stopper from a carboy, even briefly, for testing and making adjustments can allow a great deal of oxygen to enter. Racking from one open carboy to another open carboy with a siphon, a pretty standard approach when glass carboys are used, will essentially saturate the wine or beer with oxygen. Yes, traces of oxygen can diffuse through the wall of a Better-Bottle carboy, but experience indicates that the impact is negligible and more than offset by a wide range of advantages. " Jim "jim" > wrote in message ... > Their website will have been registered 4 years in April it seems. > > Jim > > "pp" > wrote in message oups.com... >> Isn't this a pretty new product? I don't remember seeing ads for them >> before 2 years or so. That's not enough time to get any decent aging >> data. >> >> Pp >> >> On Jan 8, 9:54 am, "snpm" > wrote: >>> Am I the only one who finds it a little odd that there is no obvious >>> evidence-based practice with this? >>> >>> >>> >>> RomeoMike wrote: >>> > The conclusion from this and other posts seems to be that a Better >>> > Bottle may or may not be permeable to oxygen, but even if it is, it >>> > doesn't matter because, as it turns out, a little oxygen is good anyway. >>> > Ergo, a Better Bottle may be the way to go :-) >>> >>> > Joe Sallustio wrote: >>> > > Actually it's more complicated than that for a sealed barrel. The >>> > > barrel is semi permeable and it is now thought that it actually pulls >>> > > ambient air into the wine in tiny amounts because a vacuum is created >>> > > on tightly bunged barrels. They consider this micro oxygenation and >>> > > it's good for reds. As to whether a better bottle would emulate >>> > > that, I guess it comes down to surface area and permeability. To be >>> > > honest, I don't know if they think the air comes in from toppings or >>> > > through the staves; I have seen both stated. Smaller containers have >>> > > more surface to mass ratios, if you wanted to emulate anything i would >>> > > guess the 30 to 55 gallon barrels would be the ones to go for. Maybe >>> > > Google micro oxygenation and wine or barrels. >>> >>> > > Joe- Hide quoted text -- Show quoted text - >> > > |
more thoughts on PET versus glass permeability
jim wrote:
> I don't know if this is of general interest, but here is the reply I had back from better bottle regarding permeability > and oxidation. I must say it sounds fair... > > " > Substantial, and rapidly growing, numbers of home winemakers and brewers, as > well as suppliers of kits, clearly prefer Better-Bottle's unique PET carboys > and fittings to glass carboys. Nevertheless, anecdotal reports of oxygen > diffusing through the walls of Better-Bottle carboys and causing poor > results pop up from time to time and we are asked to comment. > > Making a good wine or beer is something of an art and occasionally results > do not meet expectations, regardless of whether the winemaker or brewer uses > a glass carboy or Better-Bottle carboy. It is impossible to draw any valid > conclusions from anecdotal reports of sporadic, subtle failures, because > identifying the cause rigorously is usually impractical. Absolutely, using > carboys made from any of the common plastics that scalp flavors and are > quite permeable to oxygen will guarantee an inferior result. However, it > would be a mistake to assume that using a glass carboy will necessarily > guarantee a superior result. Rubber stoppers, especially silicone stoppers, > most common types of flexible tubing, and liquid-filled air locks can leak > lots of oxygen. Moreover, oxygen diffuses so quickly through beer and wine > that removing a stopper from a carboy, even briefly, for testing and making > adjustments can allow a great deal of oxygen to enter. Racking from one open > carboy to another open carboy with a siphon, a pretty standard approach when > glass carboys are used, will essentially saturate the wine or beer with > oxygen. Yes, traces of oxygen can diffuse through the wall of a > Better-Bottle carboy, but experience indicates that the impact is negligible > and more than offset by a wide range of advantages. > " > > Jim > > "jim" > wrote in message ... > >>Their website will have been registered 4 years in April it seems. >> >>Jim >> >>"pp" > wrote in message oups.com... >> >>>Isn't this a pretty new product? I don't remember seeing ads for them >>>before 2 years or so. That's not enough time to get any decent aging >>>data. >>> >>>Pp >>> >>>On Jan 8, 9:54 am, "snpm" > wrote: >>> >>>>Am I the only one who finds it a little odd that there is no obvious >>>>evidence-based practice with this? >>>> >>>> >>>> >>>>RomeoMike wrote: >>>> >>>>>The conclusion from this and other posts seems to be that a Better >>>>>Bottle may or may not be permeable to oxygen, but even if it is, it >>>>>doesn't matter because, as it turns out, a little oxygen is good anyway. >>>>> Ergo, a Better Bottle may be the way to go :-) >>>> >>>>>Joe Sallustio wrote: >>>>> >>>>>>Actually it's more complicated than that for a sealed barrel. The >>>>>>barrel is semi permeable and it is now thought that it actually pulls >>>>>>ambient air into the wine in tiny amounts because a vacuum is created >>>>>>on tightly bunged barrels. They consider this micro oxygenation and >>>>>>it's good for reds. As to whether a better bottle would emulate >>>>>>that, I guess it comes down to surface area and permeability. To be >>>>>>honest, I don't know if they think the air comes in from toppings or >>>>>>through the staves; I have seen both stated. Smaller containers have >>>>>>more surface to mass ratios, if you wanted to emulate anything i would >>>>>>guess the 30 to 55 gallon barrels would be the ones to go for. Maybe >>>>>>Google micro oxygenation and wine or barrels. >>>> >>>>>>Joe- Hide quoted text -- Show quoted text - >>> >> > > I'm laughing so hard at the initial BetterBottle reply that my side hurts... This is marketing hype at its best. Brief exposures of the wine to air as occurs during racking is consumed by the wine and SO2 in a day or two. That is unlike the constant resupply by oxygen diffusion through a container. From my understanding, it's more like leaving excess headspace in the container. Oh well, I'm a Doubting Thomas. I know my cranberry juice oxidizes within a year in its PET container. Is it through the lid seal or through the PET... I haven't run the experiment to find out. But I know PET is not a great oxygen diffusion barrier, so unless there is/are additional layers of good oxygen diffusion barrier material in the BetterBottle, I'd think twice about long term wine storage in a BetterBottle. Gene |
more thoughts on PET versus glass permeability
I think you'd still be in a vast majority in feeling that way.
Being a newbie I haven't yet reconciled why wineries don't usually seem to bulk age beyond a few months but home wine-makers do? Personally I believe the hype on their product for the way I am using it. I am planning to send everything to bottle within 3 months of fermentation ceasing. I have yet to hear someone come forward and say they have had a positive experience with long term aging in Better Bottles though, so I suppose that weighs in for the neigh-sayers so far. Gene, I wonder if you have you stats on PET and diffusion to refute their claims that it is of negligible permeability? I fully accept that statistics don't matter if you are finding that Better Bottles don't work for you! Jim "gene" > wrote in message . net... > jim wrote: >> I don't know if this is of general interest, but here is the reply I had back from better bottle regarding >> permeability and oxidation. I must say it sounds fair... >> >> " >> Substantial, and rapidly growing, numbers of home winemakers and brewers, as >> well as suppliers of kits, clearly prefer Better-Bottle's unique PET carboys >> and fittings to glass carboys. Nevertheless, anecdotal reports of oxygen >> diffusing through the walls of Better-Bottle carboys and causing poor >> results pop up from time to time and we are asked to comment. >> >> Making a good wine or beer is something of an art and occasionally results >> do not meet expectations, regardless of whether the winemaker or brewer uses >> a glass carboy or Better-Bottle carboy. It is impossible to draw any valid >> conclusions from anecdotal reports of sporadic, subtle failures, because >> identifying the cause rigorously is usually impractical. Absolutely, using >> carboys made from any of the common plastics that scalp flavors and are >> quite permeable to oxygen will guarantee an inferior result. However, it >> would be a mistake to assume that using a glass carboy will necessarily >> guarantee a superior result. Rubber stoppers, especially silicone stoppers, >> most common types of flexible tubing, and liquid-filled air locks can leak >> lots of oxygen. Moreover, oxygen diffuses so quickly through beer and wine >> that removing a stopper from a carboy, even briefly, for testing and making >> adjustments can allow a great deal of oxygen to enter. Racking from one open >> carboy to another open carboy with a siphon, a pretty standard approach when >> glass carboys are used, will essentially saturate the wine or beer with >> oxygen. Yes, traces of oxygen can diffuse through the wall of a >> Better-Bottle carboy, but experience indicates that the impact is negligible >> and more than offset by a wide range of advantages. >> " >> >> Jim >> >> "jim" > wrote in message ... >> >>>Their website will have been registered 4 years in April it seems. >>> >>>Jim >>> >>>"pp" > wrote in message oups.com... >>> >>>>Isn't this a pretty new product? I don't remember seeing ads for them >>>>before 2 years or so. That's not enough time to get any decent aging >>>>data. >>>> >>>>Pp >>>> >>>>On Jan 8, 9:54 am, "snpm" > wrote: >>>> >>>>>Am I the only one who finds it a little odd that there is no obvious >>>>>evidence-based practice with this? >>>>> >>>>> >>>>> >>>>>RomeoMike wrote: >>>>> >>>>>>The conclusion from this and other posts seems to be that a Better >>>>>>Bottle may or may not be permeable to oxygen, but even if it is, it >>>>>>doesn't matter because, as it turns out, a little oxygen is good anyway. >>>>>> Ergo, a Better Bottle may be the way to go :-) >>>>> >>>>>>Joe Sallustio wrote: >>>>>> >>>>>>>Actually it's more complicated than that for a sealed barrel. The >>>>>>>barrel is semi permeable and it is now thought that it actually pulls >>>>>>>ambient air into the wine in tiny amounts because a vacuum is created >>>>>>>on tightly bunged barrels. They consider this micro oxygenation and >>>>>>>it's good for reds. As to whether a better bottle would emulate >>>>>>>that, I guess it comes down to surface area and permeability. To be >>>>>>>honest, I don't know if they think the air comes in from toppings or >>>>>>>through the staves; I have seen both stated. Smaller containers have >>>>>>>more surface to mass ratios, if you wanted to emulate anything i would >>>>>>>guess the 30 to 55 gallon barrels would be the ones to go for. Maybe >>>>>>>Google micro oxygenation and wine or barrels. >>>>> >>>>>>>Joe- Hide quoted text -- Show quoted text - >>>> >>> >> >> > I'm laughing so hard at the initial BetterBottle reply that my side hurts... This is marketing hype at its best. > > Brief exposures of the wine to air as occurs during racking is consumed by the wine and SO2 in a day or two. That is > unlike the constant resupply by oxygen diffusion through a container. From my understanding, it's more like leaving > excess headspace in the container. > > Oh well, I'm a Doubting Thomas. I know my cranberry juice oxidizes within a year in its PET container. Is it through > the lid seal or through the PET... I haven't run the experiment to find out. But I know PET is not a great oxygen > diffusion barrier, so unless there is/are additional layers of good oxygen diffusion barrier material in the > BetterBottle, I'd think twice about long term wine storage in a BetterBottle. > > Gene |
more thoughts on PET versus glass permeability
jim wrote:
> I think you'd still be in a vast majority in feeling that way. > > Being a newbie I haven't yet reconciled why wineries don't usually seem to bulk age beyond a few months but home > wine-makers do? > > Personally I believe the hype on their product for the way I am using it. I am planning to send everything to bottle > within 3 months of fermentation ceasing. I have yet to hear someone come forward and say they have had a positive > experience with long term aging in Better Bottles though, so I suppose that weighs in for the neigh-sayers so far. > > Gene, I wonder if you have you stats on PET and diffusion to refute their claims that it is of negligible permeability? > I fully accept that statistics don't matter if you are finding that Better Bottles don't work for you! > > Jim > > > "gene" > wrote in message . net... > >>jim wrote: >> >>>I don't know if this is of general interest, but here is the reply I had back from better bottle regarding >>>permeability and oxidation. I must say it sounds fair... >>> >>>" >>>Substantial, and rapidly growing, numbers of home winemakers and brewers, as >>>well as suppliers of kits, clearly prefer Better-Bottle's unique PET carboys >>>and fittings to glass carboys. Nevertheless, anecdotal reports of oxygen >>>diffusing through the walls of Better-Bottle carboys and causing poor >>>results pop up from time to time and we are asked to comment. >>> >>>Making a good wine or beer is something of an art and occasionally results >>>do not meet expectations, regardless of whether the winemaker or brewer uses >>>a glass carboy or Better-Bottle carboy. It is impossible to draw any valid >>>conclusions from anecdotal reports of sporadic, subtle failures, because >>>identifying the cause rigorously is usually impractical. Absolutely, using >>>carboys made from any of the common plastics that scalp flavors and are >>>quite permeable to oxygen will guarantee an inferior result. However, it >>>would be a mistake to assume that using a glass carboy will necessarily >>>guarantee a superior result. Rubber stoppers, especially silicone stoppers, >>>most common types of flexible tubing, and liquid-filled air locks can leak >>>lots of oxygen. Moreover, oxygen diffuses so quickly through beer and wine >>>that removing a stopper from a carboy, even briefly, for testing and making >>>adjustments can allow a great deal of oxygen to enter. Racking from one open >>>carboy to another open carboy with a siphon, a pretty standard approach when >>>glass carboys are used, will essentially saturate the wine or beer with >>>oxygen. Yes, traces of oxygen can diffuse through the wall of a >>>Better-Bottle carboy, but experience indicates that the impact is negligible >>>and more than offset by a wide range of advantages. >>>" >>> >>>Jim >>> >>>"jim" > wrote in message ... >>> >>> >>>>Their website will have been registered 4 years in April it seems. >>>> >>>>Jim >>>> >>>>"pp" > wrote in message oups.com... >>>> >>>> >>>>>Isn't this a pretty new product? I don't remember seeing ads for them >>>>>before 2 years or so. That's not enough time to get any decent aging >>>>>data. >>>>> >>>>>Pp >>>>> >>>>>On Jan 8, 9:54 am, "snpm" > wrote: >>>>> >>>>> >>>>>>Am I the only one who finds it a little odd that there is no obvious >>>>>>evidence-based practice with this? >>>>>> >>>>>> >>>>>> >>>>>>RomeoMike wrote: >>>>>> >>>>>> >>>>>>>The conclusion from this and other posts seems to be that a Better >>>>>>>Bottle may or may not be permeable to oxygen, but even if it is, it >>>>>>>doesn't matter because, as it turns out, a little oxygen is good anyway. >>>>>>> Ergo, a Better Bottle may be the way to go :-) >>>>>> >>>>>>>Joe Sallustio wrote: >>>>>>> >>>>>>> >>>>>>>>Actually it's more complicated than that for a sealed barrel. The >>>>>>>>barrel is semi permeable and it is now thought that it actually pulls >>>>>>>>ambient air into the wine in tiny amounts because a vacuum is created >>>>>>>>on tightly bunged barrels. They consider this micro oxygenation and >>>>>>>>it's good for reds. As to whether a better bottle would emulate >>>>>>>>that, I guess it comes down to surface area and permeability. To be >>>>>>>>honest, I don't know if they think the air comes in from toppings or >>>>>>>>through the staves; I have seen both stated. Smaller containers have >>>>>>>>more surface to mass ratios, if you wanted to emulate anything i would >>>>>>>>guess the 30 to 55 gallon barrels would be the ones to go for. Maybe >>>>>>>>Google micro oxygenation and wine or barrels. >>>>>> >>>>>>>>Joe- Hide quoted text -- Show quoted text - >>>>> >>> >>I'm laughing so hard at the initial BetterBottle reply that my side hurts... This is marketing hype at its best. >> >>Brief exposures of the wine to air as occurs during racking is consumed by the wine and SO2 in a day or two. That is >>unlike the constant resupply by oxygen diffusion through a container. From my understanding, it's more like leaving >>excess headspace in the container. >> >>Oh well, I'm a Doubting Thomas. I know my cranberry juice oxidizes within a year in its PET container. Is it through >>the lid seal or through the PET... I haven't run the experiment to find out. But I know PET is not a great oxygen >>diffusion barrier, so unless there is/are additional layers of good oxygen diffusion barrier material in the >>BetterBottle, I'd think twice about long term wine storage in a BetterBottle. >> >>Gene > > Can't find the table of diffusivities in a hurry, but here's a reference from University of Guelph, Canada, Food Technology Center, in which PET is mentioned not being the best oxygen barrier: http://www.gftc.ca/articles/2003/packaging3.cfm Here's an interesting article about modifications to PET to improve oxygen barrier properties: http://capricenter.cwru.edu/Publishe...0copolymer.pdf Gene |
more thoughts on PET versus glass permeability
I just found a table with some polymers oxygen diffusivity.... PET
better than polycarbonate, but worse than HDPE and polypropylene. http://www.diffusion-polymers.com/gas_diffusion.htm One of the better oxygen diffusion barriers is Polyvinyl Alcohol (PVA), but it doesn't make for a very strong container, so typically would be used as a layer on the inside of the bottle. My polymers handbook is packed away, so this'll have to do for now. Gene jim wrote: > I think you'd still be in a vast majority in feeling that way. > > Being a newbie I haven't yet reconciled why wineries don't usually seem to bulk age beyond a few months but home > wine-makers do? > > Personally I believe the hype on their product for the way I am using it. I am planning to send everything to bottle > within 3 months of fermentation ceasing. I have yet to hear someone come forward and say they have had a positive > experience with long term aging in Better Bottles though, so I suppose that weighs in for the neigh-sayers so far. > > Gene, I wonder if you have you stats on PET and diffusion to refute their claims that it is of negligible permeability? > I fully accept that statistics don't matter if you are finding that Better Bottles don't work for you! > > Jim > > > "gene" > wrote in message . net... > >>jim wrote: >> >>>I don't know if this is of general interest, but here is the reply I had back from better bottle regarding >>>permeability and oxidation. I must say it sounds fair... >>> >>>" >>>Substantial, and rapidly growing, numbers of home winemakers and brewers, as >>>well as suppliers of kits, clearly prefer Better-Bottle's unique PET carboys >>>and fittings to glass carboys. Nevertheless, anecdotal reports of oxygen >>>diffusing through the walls of Better-Bottle carboys and causing poor >>>results pop up from time to time and we are asked to comment. >>> >>>Making a good wine or beer is something of an art and occasionally results >>>do not meet expectations, regardless of whether the winemaker or brewer uses >>>a glass carboy or Better-Bottle carboy. It is impossible to draw any valid >>>conclusions from anecdotal reports of sporadic, subtle failures, because >>>identifying the cause rigorously is usually impractical. Absolutely, using >>>carboys made from any of the common plastics that scalp flavors and are >>>quite permeable to oxygen will guarantee an inferior result. However, it >>>would be a mistake to assume that using a glass carboy will necessarily >>>guarantee a superior result. Rubber stoppers, especially silicone stoppers, >>>most common types of flexible tubing, and liquid-filled air locks can leak >>>lots of oxygen. Moreover, oxygen diffuses so quickly through beer and wine >>>that removing a stopper from a carboy, even briefly, for testing and making >>>adjustments can allow a great deal of oxygen to enter. Racking from one open >>>carboy to another open carboy with a siphon, a pretty standard approach when >>>glass carboys are used, will essentially saturate the wine or beer with >>>oxygen. Yes, traces of oxygen can diffuse through the wall of a >>>Better-Bottle carboy, but experience indicates that the impact is negligible >>>and more than offset by a wide range of advantages. >>>" >>> >>>Jim >>> >>>"jim" > wrote in message ... >>> >>> >>>>Their website will have been registered 4 years in April it seems. >>>> >>>>Jim >>>> >>>>"pp" > wrote in message oups.com... >>>> >>>> >>>>>Isn't this a pretty new product? I don't remember seeing ads for them >>>>>before 2 years or so. That's not enough time to get any decent aging >>>>>data. >>>>> >>>>>Pp >>>>> >>>>>On Jan 8, 9:54 am, "snpm" > wrote: >>>>> >>>>> >>>>>>Am I the only one who finds it a little odd that there is no obvious >>>>>>evidence-based practice with this? >>>>>> >>>>>> >>>>>> >>>>>>RomeoMike wrote: >>>>>> >>>>>> >>>>>>>The conclusion from this and other posts seems to be that a Better >>>>>>>Bottle may or may not be permeable to oxygen, but even if it is, it >>>>>>>doesn't matter because, as it turns out, a little oxygen is good anyway. >>>>>>> Ergo, a Better Bottle may be the way to go :-) >>>>>> >>>>>>>Joe Sallustio wrote: >>>>>>> >>>>>>> >>>>>>>>Actually it's more complicated than that for a sealed barrel. The >>>>>>>>barrel is semi permeable and it is now thought that it actually pulls >>>>>>>>ambient air into the wine in tiny amounts because a vacuum is created >>>>>>>>on tightly bunged barrels. They consider this micro oxygenation and >>>>>>>>it's good for reds. As to whether a better bottle would emulate >>>>>>>>that, I guess it comes down to surface area and permeability. To be >>>>>>>>honest, I don't know if they think the air comes in from toppings or >>>>>>>>through the staves; I have seen both stated. Smaller containers have >>>>>>>>more surface to mass ratios, if you wanted to emulate anything i would >>>>>>>>guess the 30 to 55 gallon barrels would be the ones to go for. Maybe >>>>>>>>Google micro oxygenation and wine or barrels. >>>>>> >>>>>>>>Joe- Hide quoted text -- Show quoted text - >>>>> >>> >>I'm laughing so hard at the initial BetterBottle reply that my side hurts... This is marketing hype at its best. >> >>Brief exposures of the wine to air as occurs during racking is consumed by the wine and SO2 in a day or two. That is >>unlike the constant resupply by oxygen diffusion through a container. From my understanding, it's more like leaving >>excess headspace in the container. >> >>Oh well, I'm a Doubting Thomas. I know my cranberry juice oxidizes within a year in its PET container. Is it through >>the lid seal or through the PET... I haven't run the experiment to find out. But I know PET is not a great oxygen >>diffusion barrier, so unless there is/are additional layers of good oxygen diffusion barrier material in the >>BetterBottle, I'd think twice about long term wine storage in a BetterBottle. >> >>Gene > > > |
more thoughts on PET versus glass permeability
For those that haven't actually touched a Better Bottle, the plastic
used is rigid, unlike a PET pop bottle. They're more like the V8 plastic bottles that we get in Canada (and probably the US, but I'm not certain). I know that this doesn't answer the permeability question, but results from storing wine in PET pop bottles may be different from Better Bottles. On Wed, 10 Jan 2007 00:18:28 -0000, "jim" > wrote: >Being a newbie I haven't yet reconciled why wineries don't usually seem to bulk age beyond a few months but home >wine-makers do? Not sure what commercial wines you're buying, but in local (BC Canada) liquor stores many of the reds being sold are from 2002-2003-2004. Yes whites are from 2005, may be even 2006 if from the southern hemisphere. Steve |
more thoughts on PET versus glass permeability
Thanks for the information Gene, it was useful if not hard reading to a non chemist but appreciated! It does indeed
spell out that standard PET is far from O2-tight :) I think Steve picked up on a useful point there though. The Better-Bottle.com website does suggest, albeit a little mystically, that BBs are made from a 'special PET' with negligible permeability. In scanning the pdf articles I saw that Anna Polyakova says it IS possible to produce a PET which is 'considered impermeable' via two stated methods. I am not sure then whether discussing the properties of standard PET applies as Steve said. On paper it is down to whether Better Bottles 'special PET' is one of these improved types or standard PET. I currently expect the latter. Jim "Steve" > wrote in message ... > For those that haven't actually touched a Better Bottle, the plastic > used is rigid, unlike a PET pop bottle. They're more like the V8 > plastic bottles that we get in Canada (and probably the US, but I'm > not certain). > > I know that this doesn't answer the permeability question, but results > from storing wine in PET pop bottles may be different from Better > Bottles. > > > On Wed, 10 Jan 2007 00:18:28 -0000, "jim" > > wrote: > >>Being a newbie I haven't yet reconciled why wineries don't usually seem to bulk age beyond a few months but home >>wine-makers do? > > Not sure what commercial wines you're buying, but in local (BC Canada) > liquor stores many of the reds being sold are from 2002-2003-2004. > Yes whites are from 2005, may be even 2006 if from the southern > hemisphere. > > Steve |
more thoughts on PET versus glass permeability
Good eye, Jim. Yes, it is possible to lower the oxygen permeability of
PET as Anna Polyakova (cute name for someone working with polymers, BTW). I'll dig for that patent application info, but I'm disappointed that Better Bottle hasn't put the oxygen diffusivity numbers in their technical specifications page for us to VERIFY their claim, not imposing upon us to pay for the testing that they should use to validate the claim in the first place. We're not all 'Bayer Aspirin' trusting souls, lol. The stiffness of the PET has much to do with the degree of crystallinity (i.e. cross-linking) of the polymer as part of the polymerization process. The more cross-linking, the stiffer. The pop bottle PET is more flexible primarily because it has less cross-linking. In polymer science terms that is a 'lower average molecular weight' polymer. So better bottle is higher average molecular weight.... that alone can be the basis of a claim of 'special PET'. I'm not saying the BB is bad. I still am a Doubting Thomas because there are not cold, hard oxygen diffusivity numbers published by BB to back their claim. I've been a materials scientist qualifying materials into manufacturing processes too long to take my supplier's claims at face value. It is buyer beware in the world of suppliers. Gene jim wrote: > Thanks for the information Gene, it was useful if not hard reading to a non chemist but appreciated! It does indeed > spell out that standard PET is far from O2-tight :) > > I think Steve picked up on a useful point there though. The Better-Bottle.com website does suggest, albeit a little > mystically, that BBs are made from a 'special PET' with negligible permeability. In scanning the pdf articles I saw > that Anna Polyakova says it IS possible to produce a PET which is 'considered impermeable' via two stated methods. > > I am not sure then whether discussing the properties of standard PET applies as Steve said. On paper it is down to > whether Better Bottles 'special PET' is one of these improved types or standard PET. I currently expect the latter. > > Jim > > "Steve" > wrote in message ... > >>For those that haven't actually touched a Better Bottle, the plastic >>used is rigid, unlike a PET pop bottle. They're more like the V8 >>plastic bottles that we get in Canada (and probably the US, but I'm >>not certain). >> >>I know that this doesn't answer the permeability question, but results >>from storing wine in PET pop bottles may be different from Better >>Bottles. >> >> >>On Wed, 10 Jan 2007 00:18:28 -0000, "jim" > >>wrote: >> >> >>>Being a newbie I haven't yet reconciled why wineries don't usually seem to bulk age beyond a few months but home >>>wine-makers do? >> >>Not sure what commercial wines you're buying, but in local (BC Canada) >>liquor stores many of the reds being sold are from 2002-2003-2004. >>Yes whites are from 2005, may be even 2006 if from the southern >>hemisphere. >> >>Steve > > > |
Correction - more thoughts on PET versus glass permeability
Correction:
I read the oxygen solubility column rather than diffusivity column when I made my below statement. gene wrote: > I just found a table with some polymers oxygen diffusivity.... PET > better than polycarbonate, but worse than HDPE and polypropylene. I apologize for any confusion which may have arisen due to the error which I committed somewhere between my eyes and my fingers, most likely in the cranial cavity, lol. For oxygen diffusivity, PET is one of the better polymers between 1-2 orders of magnitude lower than polypropylene, HDPE, polycarbonate. Not quite as good as unplasticized, unfilled PVC. Not nearly as good as PVA. I finally found an article which has PET and PVA (in this case EVOH, ethylvinyl alcohol, one of the PVA family of polymers). http://www.chemsoc.org/chembytes/ezi...kett_jul02.htm EVOH is almost two orders of magnitude lower oxygen diffusivity than PET, with the caveat that the EVOH would have to be a buried layer, not directly in contact with liquid. EVOH in contact with liquid is no better than PET for oxygen diffusion. Gene > > http://www.diffusion-polymers.com/gas_diffusion.htm > > One of the better oxygen diffusion barriers is Polyvinyl Alcohol (PVA), > but it doesn't make for a very strong container, so typically would be > used as a layer on the inside of the bottle. > My polymers handbook is packed away, so this'll have to do for now. > > Gene > > jim wrote: > >> I think you'd still be in a vast majority in feeling that way. >> >> Being a newbie I haven't yet reconciled why wineries don't usually >> seem to bulk age beyond a few months but home wine-makers do? >> >> Personally I believe the hype on their product for the way I am using >> it. I am planning to send everything to bottle within 3 months of >> fermentation ceasing. I have yet to hear someone come forward and say >> they have had a positive experience with long term aging in Better >> Bottles though, so I suppose that weighs in for the neigh-sayers so far. >> >> Gene, I wonder if you have you stats on PET and diffusion to refute >> their claims that it is of negligible permeability? I fully accept >> that statistics don't matter if you are finding that Better Bottles >> don't work for you! >> >> Jim >> >> >> "gene" > wrote in message >> . net... >> >>> jim wrote: >>> >>>> I don't know if this is of general interest, but here is the reply I >>>> had back from better bottle regarding permeability and oxidation. I >>>> must say it sounds fair... >>>> >>>> " >>>> Substantial, and rapidly growing, numbers of home winemakers and >>>> brewers, as >>>> well as suppliers of kits, clearly prefer Better-Bottle's unique PET >>>> carboys >>>> and fittings to glass carboys. Nevertheless, anecdotal reports of >>>> oxygen >>>> diffusing through the walls of Better-Bottle carboys and causing poor >>>> results pop up from time to time and we are asked to comment. >>>> >>>> Making a good wine or beer is something of an art and occasionally >>>> results >>>> do not meet expectations, regardless of whether the winemaker or >>>> brewer uses >>>> a glass carboy or Better-Bottle carboy. It is impossible to draw any >>>> valid >>>> conclusions from anecdotal reports of sporadic, subtle failures, >>>> because >>>> identifying the cause rigorously is usually impractical. Absolutely, >>>> using >>>> carboys made from any of the common plastics that scalp flavors and are >>>> quite permeable to oxygen will guarantee an inferior result. >>>> However, it >>>> would be a mistake to assume that using a glass carboy will necessarily >>>> guarantee a superior result. Rubber stoppers, especially silicone >>>> stoppers, >>>> most common types of flexible tubing, and liquid-filled air locks >>>> can leak >>>> lots of oxygen. Moreover, oxygen diffuses so quickly through beer >>>> and wine >>>> that removing a stopper from a carboy, even briefly, for testing and >>>> making >>>> adjustments can allow a great deal of oxygen to enter. Racking from >>>> one open >>>> carboy to another open carboy with a siphon, a pretty standard >>>> approach when >>>> glass carboys are used, will essentially saturate the wine or beer with >>>> oxygen. Yes, traces of oxygen can diffuse through the wall of a >>>> Better-Bottle carboy, but experience indicates that the impact is >>>> negligible >>>> and more than offset by a wide range of advantages. >>>> " >>>> >>>> Jim >>>> >>>> "jim" > wrote in message >>>> ... >>>> >>>> >>>>> Their website will have been registered 4 years in April it seems. >>>>> >>>>> Jim >>>>> >>>>> "pp" > wrote in message >>>>> oups.com... >>>>> >>>>> >>>>>> Isn't this a pretty new product? I don't remember seeing ads for them >>>>>> before 2 years or so. That's not enough time to get any decent aging >>>>>> data. >>>>>> >>>>>> Pp >>>>>> >>>>>> On Jan 8, 9:54 am, "snpm" > wrote: >>>>>> >>>>>> >>>>>>> Am I the only one who finds it a little odd that there is no obvious >>>>>>> evidence-based practice with this? >>>>>>> >>>>>>> >>>>>>> >>>>>>> RomeoMike wrote: >>>>>>> >>>>>>> >>>>>>>> The conclusion from this and other posts seems to be that a Better >>>>>>>> Bottle may or may not be permeable to oxygen, but even if it is, it >>>>>>>> doesn't matter because, as it turns out, a little oxygen is good >>>>>>>> anyway. >>>>>>>> Ergo, a Better Bottle may be the way to go :-) >>>>>>> >>>>>>> >>>>>>>> Joe Sallustio wrote: >>>>>>>> >>>>>>>> >>>>>>>>> Actually it's more complicated than that for a sealed barrel. The >>>>>>>>> barrel is semi permeable and it is now thought that it actually >>>>>>>>> pulls >>>>>>>>> ambient air into the wine in tiny amounts because a vacuum is >>>>>>>>> created >>>>>>>>> on tightly bunged barrels. They consider this micro >>>>>>>>> oxygenation and >>>>>>>>> it's good for reds. As to whether a better bottle would emulate >>>>>>>>> that, I guess it comes down to surface area and permeability. >>>>>>>>> To be >>>>>>>>> honest, I don't know if they think the air comes in from >>>>>>>>> toppings or >>>>>>>>> through the staves; I have seen both stated. Smaller >>>>>>>>> containers have >>>>>>>>> more surface to mass ratios, if you wanted to emulate anything >>>>>>>>> i would >>>>>>>>> guess the 30 to 55 gallon barrels would be the ones to go for. >>>>>>>>> Maybe >>>>>>>>> Google micro oxygenation and wine or barrels. >>>>>>> >>>>>>> >>>>>>>>> Joe- Hide quoted text -- Show quoted text - >>>>>> >>>>>> >>>> >>> I'm laughing so hard at the initial BetterBottle reply that my side >>> hurts... This is marketing hype at its best. >>> >>> Brief exposures of the wine to air as occurs during racking is >>> consumed by the wine and SO2 in a day or two. That is unlike the >>> constant resupply by oxygen diffusion through a container. From my >>> understanding, it's more like leaving excess headspace in the container. >>> >>> Oh well, I'm a Doubting Thomas. I know my cranberry juice oxidizes >>> within a year in its PET container. Is it through the lid seal or >>> through the PET... I haven't run the experiment to find out. But I >>> know PET is not a great oxygen diffusion barrier, so unless there >>> is/are additional layers of good oxygen diffusion barrier material in >>> the BetterBottle, I'd think twice about long term wine storage in a >>> BetterBottle. >>> >>> Gene >> >> >> >> |
more thoughts on PET versus glass permeability
I totally agree with you Gene. Facts should be put on the table. Better
bottle say their patent is pending. Hopefully someone with enough know how amongst us will be able to read that patent app and make sense of whether BB is a step forward or not. If their patent is in process then they have no worries or fears of anyone stealing their idea. My practical nature hopes it is not all shill, since BB is ridiculously lighter than glass!! Sean gene wrote: > Good eye, Jim. Yes, it is possible to lower the oxygen permeability of > PET as Anna Polyakova (cute name for someone working with polymers, > BTW). I'll dig for that patent application info, but I'm disappointed > that Better Bottle hasn't put the oxygen diffusivity numbers in their > technical specifications page for us to VERIFY their claim, not imposing > upon us to pay for the testing that they should use to validate the > claim in the first place. We're not all 'Bayer Aspirin' trusting souls, > lol. > > The stiffness of the PET has much to do with the degree of crystallinity > (i.e. cross-linking) of the polymer as part of the polymerization > process. The more cross-linking, the stiffer. The pop bottle PET is > more flexible primarily because it has less cross-linking. In polymer > science terms that is a 'lower average molecular weight' polymer. So > better bottle is higher average molecular weight.... that alone can be > the basis of a claim of 'special PET'. I'm not saying the BB is bad. I > still am a Doubting Thomas because there are not cold, hard oxygen > diffusivity numbers published by BB to back their claim. I've been a > materials scientist qualifying materials into manufacturing processes > too long to take my supplier's claims at face value. It is buyer beware > in the world of suppliers. > > Gene > > jim wrote: > > Thanks for the information Gene, it was useful if not hard reading to a non chemist but appreciated! It does indeed > > spell out that standard PET is far from O2-tight :) > > > > I think Steve picked up on a useful point there though. The Better-Bottle.com website does suggest, albeit a little > > mystically, that BBs are made from a 'special PET' with negligible permeability. In scanning the pdf articles I saw > > that Anna Polyakova says it IS possible to produce a PET which is 'considered impermeable' via two stated methods. > > > > I am not sure then whether discussing the properties of standard PET applies as Steve said. On paper it is down to > > whether Better Bottles 'special PET' is one of these improved types or standard PET. I currently expect the latter. > > > > Jim > > > > "Steve" > wrote in message ... > > > >>For those that haven't actually touched a Better Bottle, the plastic > >>used is rigid, unlike a PET pop bottle. They're more like the V8 > >>plastic bottles that we get in Canada (and probably the US, but I'm > >>not certain). > >> > >>I know that this doesn't answer the permeability question, but results > >>from storing wine in PET pop bottles may be different from Better > >>Bottles. > >> > >> > >>On Wed, 10 Jan 2007 00:18:28 -0000, "jim" > > >>wrote: > >> > >> > >>>Being a newbie I haven't yet reconciled why wineries don't usually seem to bulk age beyond a few months but home > >>>wine-makers do? > >> > >>Not sure what commercial wines you're buying, but in local (BC Canada) > >>liquor stores many of the reds being sold are from 2002-2003-2004. > >>Yes whites are from 2005, may be even 2006 if from the southern > >>hemisphere. > >> > >>Steve > > > > > > |
more thoughts on PET versus glass permeability
I wish they'd provide statistics too. Hi Gene, and thanks for the info!
The last bit of information I got from Better Bottle regarding the material used for hte Better Bottles was this: " There are many formulations for PET as used in products. Pure PET is a much better barrier than most other plastics; however, with the addition of certain copolymers and the right stretching, it becomes much more impermeable. We use a copolymer that has an extremely low permeability, and we are working to make formulation that have such low permeability that they can be used to produce 750 ml, re-usable wine and beer bottles to replace glass. Crystallized PET is what we use for our fittings. " I did ask in the first instance for stats, but they obviously don't give those out. Cheers again, Jim "snpm" > wrote in message oups.com... >I totally agree with you Gene. Facts should be put on the table. Better > bottle say their patent is pending. Hopefully someone with enough know > how amongst us will be able to read that patent app and make sense of > whether BB is a step forward or not. If their patent is in process then > they have no worries or fears of anyone stealing their idea. My > practical nature hopes it is not all shill, since BB is ridiculously > lighter than glass!! > > Sean > > > gene wrote: >> Good eye, Jim. Yes, it is possible to lower the oxygen permeability of >> PET as Anna Polyakova (cute name for someone working with polymers, >> BTW). I'll dig for that patent application info, but I'm disappointed >> that Better Bottle hasn't put the oxygen diffusivity numbers in their >> technical specifications page for us to VERIFY their claim, not imposing >> upon us to pay for the testing that they should use to validate the >> claim in the first place. We're not all 'Bayer Aspirin' trusting souls, >> lol. >> >> The stiffness of the PET has much to do with the degree of crystallinity >> (i.e. cross-linking) of the polymer as part of the polymerization >> process. The more cross-linking, the stiffer. The pop bottle PET is >> more flexible primarily because it has less cross-linking. In polymer >> science terms that is a 'lower average molecular weight' polymer. So >> better bottle is higher average molecular weight.... that alone can be >> the basis of a claim of 'special PET'. I'm not saying the BB is bad. I >> still am a Doubting Thomas because there are not cold, hard oxygen >> diffusivity numbers published by BB to back their claim. I've been a >> materials scientist qualifying materials into manufacturing processes >> too long to take my supplier's claims at face value. It is buyer beware >> in the world of suppliers. >> >> Gene >> >> jim wrote: >> > Thanks for the information Gene, it was useful if not hard reading to a non chemist but appreciated! It does >> > indeed >> > spell out that standard PET is far from O2-tight :) >> > >> > I think Steve picked up on a useful point there though. The Better-Bottle.com website does suggest, albeit a >> > little >> > mystically, that BBs are made from a 'special PET' with negligible permeability. In scanning the pdf articles I >> > saw >> > that Anna Polyakova says it IS possible to produce a PET which is 'considered impermeable' via two stated methods. >> > >> > I am not sure then whether discussing the properties of standard PET applies as Steve said. On paper it is down to >> > whether Better Bottles 'special PET' is one of these improved types or standard PET. I currently expect the >> > latter. >> > >> > Jim >> > >> > "Steve" > wrote in message ... >> > >> >>For those that haven't actually touched a Better Bottle, the plastic >> >>used is rigid, unlike a PET pop bottle. They're more like the V8 >> >>plastic bottles that we get in Canada (and probably the US, but I'm >> >>not certain). >> >> >> >>I know that this doesn't answer the permeability question, but results >> >>from storing wine in PET pop bottles may be different from Better >> >>Bottles. >> >> >> >> >> >>On Wed, 10 Jan 2007 00:18:28 -0000, "jim" > >> >>wrote: >> >> >> >> >> >>>Being a newbie I haven't yet reconciled why wineries don't usually seem to bulk age beyond a few months but home >> >>>wine-makers do? >> >> >> >>Not sure what commercial wines you're buying, but in local (BC Canada) >> >>liquor stores many of the reds being sold are from 2002-2003-2004. >> >>Yes whites are from 2005, may be even 2006 if from the southern >> >>hemisphere. >> >> >> >>Steve >> > >> > >> > > |
more thoughts on PET versus glass permeability
I made a cranial processing error when writing the first sentence below.
I looked at the oxygen solubility column rather than the oxygen diffusivity column. OOPS. PET is betwen one and two orders of magnitude lower oxygen diffusivity than polycarbonate, HDPE and polypropylene. But PET still at least 100X (could be up to 1000x) worse than in glass containers. In winemaking terms, white wines stored in sealed glass carboys might be expected to last 2 to 3 times as long as in virgin PET containers, if there are no other air leaks past the stopper. For red wines, PET carboys might be a good thing. PET has slower micro-oxidation rate than HDPE, which is used by some aussie wineries for reds aging. For white wines, you don't want any micro-oxidation. Please note that PET is on the order of 20 times higher oxygen diffusivity compared to EVOH (ethylvinyl alcohol, a member of the polyvinyl alcohol family). However, there is a caveat for EVOH... it's oxygen barrier properties are no better than PET when in direct contact with water, so EVOH must be a buried layer in a polymer 'sandwich' to get benefit of it's better oxygen barrier properties. I'm having trouble finding the oxygen diffusivity for glass, to compare against all polymers. Dang, I wish my materials science reference books weren't in storage. If I recall correctly, glass is between 2 and 4 orders of magnitude better than polymers for oxygen diffusivity (100 to 10,000 times better) for the same thickness. Now, as we all know, glass carboys are thicker, so the glass carboy is hella lower total oxygen diffusion rate than any plastic carboy. The oxygen getting into wine in a glass carboy, for all practical purposes, only comes through the airlock stopper or leaks between the stopper and the glass. Gene gene wrote: > I just found a table with some polymers oxygen diffusivity.... PET > better than polycarbonate, but worse than HDPE and polypropylene. > > http://www.diffusion-polymers.com/gas_diffusion.htm > > One of the better oxygen diffusion barriers is Polyvinyl Alcohol (PVA), > but it doesn't make for a very strong container, so typically would be > used as a layer on the inside of the bottle. > My polymers handbook is packed away, so this'll have to do for now. > > Gene > > jim wrote: > >> I think you'd still be in a vast majority in feeling that way. >> >> Being a newbie I haven't yet reconciled why wineries don't usually >> seem to bulk age beyond a few months but home wine-makers do? >> >> Personally I believe the hype on their product for the way I am using >> it. I am planning to send everything to bottle within 3 months of >> fermentation ceasing. I have yet to hear someone come forward and say >> they have had a positive experience with long term aging in Better >> Bottles though, so I suppose that weighs in for the neigh-sayers so far. >> >> Gene, I wonder if you have you stats on PET and diffusion to refute >> their claims that it is of negligible permeability? I fully accept >> that statistics don't matter if you are finding that Better Bottles >> don't work for you! >> >> Jim >> >> >> "gene" > wrote in message >> . net... >> >>> jim wrote: >>> >>>> I don't know if this is of general interest, but here is the reply I >>>> had back from better bottle regarding permeability and oxidation. I >>>> must say it sounds fair... >>>> >>>> " >>>> Substantial, and rapidly growing, numbers of home winemakers and >>>> brewers, as >>>> well as suppliers of kits, clearly prefer Better-Bottle's unique PET >>>> carboys >>>> and fittings to glass carboys. Nevertheless, anecdotal reports of >>>> oxygen >>>> diffusing through the walls of Better-Bottle carboys and causing poor >>>> results pop up from time to time and we are asked to comment. >>>> >>>> Making a good wine or beer is something of an art and occasionally >>>> results >>>> do not meet expectations, regardless of whether the winemaker or >>>> brewer uses >>>> a glass carboy or Better-Bottle carboy. It is impossible to draw any >>>> valid >>>> conclusions from anecdotal reports of sporadic, subtle failures, >>>> because >>>> identifying the cause rigorously is usually impractical. Absolutely, >>>> using >>>> carboys made from any of the common plastics that scalp flavors and are >>>> quite permeable to oxygen will guarantee an inferior result. >>>> However, it >>>> would be a mistake to assume that using a glass carboy will necessarily >>>> guarantee a superior result. Rubber stoppers, especially silicone >>>> stoppers, >>>> most common types of flexible tubing, and liquid-filled air locks >>>> can leak >>>> lots of oxygen. Moreover, oxygen diffuses so quickly through beer >>>> and wine >>>> that removing a stopper from a carboy, even briefly, for testing and >>>> making >>>> adjustments can allow a great deal of oxygen to enter. Racking from >>>> one open >>>> carboy to another open carboy with a siphon, a pretty standard >>>> approach when >>>> glass carboys are used, will essentially saturate the wine or beer with >>>> oxygen. Yes, traces of oxygen can diffuse through the wall of a >>>> Better-Bottle carboy, but experience indicates that the impact is >>>> negligible >>>> and more than offset by a wide range of advantages. >>>> " >>>> >>>> Jim >>>> >>>> "jim" > wrote in message >>>> ... >>>> >>>> >>>>> Their website will have been registered 4 years in April it seems. >>>>> >>>>> Jim >>>>> >>>>> "pp" > wrote in message >>>>> oups.com... >>>>> >>>>> >>>>>> Isn't this a pretty new product? I don't remember seeing ads for them >>>>>> before 2 years or so. That's not enough time to get any decent aging >>>>>> data. >>>>>> >>>>>> Pp >>>>>> >>>>>> On Jan 8, 9:54 am, "snpm" > wrote: >>>>>> >>>>>> >>>>>>> Am I the only one who finds it a little odd that there is no obvious >>>>>>> evidence-based practice with this? >>>>>>> >>>>>>> >>>>>>> >>>>>>> RomeoMike wrote: >>>>>>> >>>>>>> >>>>>>>> The conclusion from this and other posts seems to be that a Better >>>>>>>> Bottle may or may not be permeable to oxygen, but even if it is, it >>>>>>>> doesn't matter because, as it turns out, a little oxygen is good >>>>>>>> anyway. >>>>>>>> Ergo, a Better Bottle may be the way to go :-) >>>>>>> >>>>>>> >>>>>>>> Joe Sallustio wrote: >>>>>>>> >>>>>>>> >>>>>>>>> Actually it's more complicated than that for a sealed barrel. The >>>>>>>>> barrel is semi permeable and it is now thought that it actually >>>>>>>>> pulls >>>>>>>>> ambient air into the wine in tiny amounts because a vacuum is >>>>>>>>> created >>>>>>>>> on tightly bunged barrels. They consider this micro >>>>>>>>> oxygenation and >>>>>>>>> it's good for reds. As to whether a better bottle would emulate >>>>>>>>> that, I guess it comes down to surface area and permeability. >>>>>>>>> To be >>>>>>>>> honest, I don't know if they think the air comes in from >>>>>>>>> toppings or >>>>>>>>> through the staves; I have seen both stated. Smaller >>>>>>>>> containers have >>>>>>>>> more surface to mass ratios, if you wanted to emulate anything >>>>>>>>> i would >>>>>>>>> guess the 30 to 55 gallon barrels would be the ones to go for. >>>>>>>>> Maybe >>>>>>>>> Google micro oxygenation and wine or barrels. >>>>>>> >>>>>>> >>>>>>>>> Joe- Hide quoted text -- Show quoted text - >>>>>> >>>>>> >>>> >>> I'm laughing so hard at the initial BetterBottle reply that my side >>> hurts... This is marketing hype at its best. >>> >>> Brief exposures of the wine to air as occurs during racking is >>> consumed by the wine and SO2 in a day or two. That is unlike the >>> constant resupply by oxygen diffusion through a container. From my >>> understanding, it's more like leaving excess headspace in the container. >>> >>> Oh well, I'm a Doubting Thomas. I know my cranberry juice oxidizes >>> within a year in its PET container. Is it through the lid seal or >>> through the PET... I haven't run the experiment to find out. But I >>> know PET is not a great oxygen diffusion barrier, so unless there >>> is/are additional layers of good oxygen diffusion barrier material in >>> the BetterBottle, I'd think twice about long term wine storage in a >>> BetterBottle. >>> >>> Gene >> >> >> >> |
more thoughts on PET versus glass permeability
>>> Being a newbie I haven't yet reconciled why wineries don't
>>> usually seem to bulk age beyond a few months but home >>> wine-makers do? Because they are in production business in which aging does not add enough to the bottom line to justify it. It's similar to American 'Big Three' Brewers who can sell 'swill' as fast as they can make it. Why bother with improving product? >> Not sure what commercial wines you're buying, but in local >> (BC Canada) liquor stores many of the reds being sold are >> from 2002-2003-2004. Yes whites are from 2005, may be even >> 2006 if from the southern hemisphere. Take a look at the year on 'Two Buck Chuck'. > For those that haven't actually touched a Better Bottle, the plastic > used is rigid, unlike a PET pop bottle. They're more like the V8 > plastic bottles that we get in Canada (and probably the US, but I'm > not certain). It's still PET. Miller is bottling beer in plastic bottles ans assert that the shelf life is six months. > I know that this doesn't answer the permeability question, but > results from storing wine in PET pop bottles may be different > from Better Bottles. There is nothing wrong with Pet soda bottles for storing wine, mead, or beer you intend to drink in the next 30 days. Is there any evidence that a Better Bottle has an oxygen barrier that will hold up for one to three years? I'd like to read it. Dick |
more thoughts on PET versus glass permeability
Dick wrote....
> there any evidence that a Better Bottle has an oxygen barrier > that will hold up for one to three years? I'd like to read it. Dick, we all would! |
more thoughts on PET versus glass permeability
>>> Not sure what commercial wines you're buying, but in local >>> (BC Canada) liquor stores many of the reds being sold are >>> from 2002-2003-2004. Yes whites are from 2005, may be even >>> 2006 if from the southern hemisphere. > >Take a look at the year on 'Two Buck Chuck'. > SInce the closest place to get Three Buck Chuck that I know for certain (ie there could be closer) is a full days drive in the summer, I won't be doing that anytime soon. Steve |
more thoughts on PET versus glass permeability
> >Take a look at the year on 'Two Buck Chuck'.
> > > SInce the closest place to get Three Buck Chuck that I know for > certain (ie there could be closer) is a full days drive in the summer, > I won't be doing that anytime soon. > It's 3 bucks here now too and it's not that special. It's ok wine and you get a bottle to reuse. As to the long term storage if we had a local supplier I would try one. I looked them up and they aren't much more than glass. I rarely go over a year in glass, I'm not making artisan wine. Joe |
more thoughts on PET versus glass permeability
It made me smile when I saw her name Gene I must admit ;)
I must admit I will be / am happy to make wine as good as commercial wineries so it doesn't pain me if I can't use the BB for reliable aging beyond a few months. I'll no doubt realise my ignorance when I taste a glass bulk-aged wine in later life. I agree with the general sentiment. "Stats out for the lads." Otherwise we are all just speculating on the minutae on the assumption that they are being honest/dishonest with their advertising claims. It seems unlikely that they / their supplier have never measured the permeability of their product. The spiral of silence suggests that the figures don't look as good on paper as they'd like them too. It's a reasonable assumption. As to whether they feel it looks bad or will make people think it is bad (remembering how permeable barrels are) I suppose that's another opinion with no substantiation. Thanks for posting this thread though, it's useful stuff... |
more thoughts on PET versus glass permeability
Here in North Carolina, $2 buck Chuck is $2.99 (Trader Joe's just opened
in Cary, a suburb of Raleigh). I agree, it's an OK wine. I have used it to blend and that works well. I had a Shiraz that was kinda weak, so I added 18% Two Buck Chuck's Cab Sauv. And now it's real nice. It took a week after blending to clear up. But I am really liking this blend. And I got some bottles added to my inventory. smile. As far as Better Bottles - I have one, use it more often than my heavy glass ones. I did have an oxidized wine from bulk aging, and I had it in the BB for 5 months. Not sure it was the bottle or something I did, though. So this is anecdotal and fyi. It drank OK early, but now I'm stuck with 9 bottles of vinegar. DAve Joe Sallustio wrote: >>> Take a look at the year on 'Two Buck Chuck'. >>> >> SInce the closest place to get Three Buck Chuck that I know for >> certain (ie there could be closer) is a full days drive in the summer, >> I won't be doing that anytime soon. >> > It's 3 bucks here now too and it's not that special. It's ok wine and > you get a bottle to reuse. > > As to the long term storage if we had a local supplier I would try one. > I looked them up and they aren't much more than glass. I rarely go > over a year in glass, I'm not making artisan wine. > > Joe > |
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