fermenting stuck
 

Hi. Here I go with my first post to this group. I've enjoyed
following it for some time from the side lines.

Here's my question...

I am making about 3 gallons of an apple wine that I started with some
lovely fresh apples. All was going exceedingly well until this week
all seems to have stopped. I have been watching the batch carefully
and there is definitely nothing going on inside that carboy. The
spec.gravity has stopped at 1025, so it's not quite ready to finish
just yet.

I have done some reading about re-starting the fermentation process,
what I wanted was some opinions on what might be going on. I also
want to be bold and just outright ask "What WOULD happen if I just
added more yeast to the batch, obviously there is still sugar to feed
the yeast, etc?"

I realize this is my ignorance showing and I appreciate what guidance
can be offered in return.

Cheers, thanks.

Chris Mears
Charlottetown, PEI, Canada

fermenting stuck
 

hi chris & welcome... can you tell us please: what was yr starting SG &
what yeast did you use? did you taking any other readings like TA or pH?
also what else besides apples is in the 3 gals you've got going? You can
always pitch more yeast...but that could just stall too. More info will
allow your question to be answered more thoroughly. regards, bob


"chrismears" > wrote in message
...
> Hi. Here I go with my first post to this group. I've enjoyed
> following it for some time from the side lines.
>
> Here's my question...
>
> I am making about 3 gallons of an apple wine that I started with some
> lovely fresh apples. All was going exceedingly well until this week
> all seems to have stopped. I have been watching the batch carefully
> and there is definitely nothing going on inside that carboy. The
> spec.gravity has stopped at 1025, so it's not quite ready to finish
> just yet.
>
> I have done some reading about re-starting the fermentation process,
> what I wanted was some opinions on what might be going on. I also
> want to be bold and just outright ask "What WOULD happen if I just
> added more yeast to the batch, obviously there is still sugar to feed
> the yeast, etc?"
>
> I realize this is my ignorance showing and I appreciate what guidance
> can be offered in return.
>
> Cheers, thanks.
>
> Chris Mears
> Charlottetown, PEI, Canada

fermenting stuck
 

On Nov 23, 3:46 pm, chrismears > wrote:
> Hi. Here I go with my first post to this group. I've enjoyed
> following it for some time from the side lines.
>
> Here's my question...
>
> I am making about 3 gallons of an apple wine that I started with some
> lovely fresh apples. All was going exceedingly well until this week
> all seems to have stopped. I have been watching the batch carefully
> and there is definitely nothing going on inside that carboy. The
> spec.gravity has stopped at 1025, so it's not quite ready to finish
> just yet.
>
> I have done some reading about re-starting the fermentation process,
> what I wanted was some opinions on what might be going on. I also
> want to be bold and just outright ask "What WOULD happen if I just
> added more yeast to the batch, obviously there is still sugar to feed
> the yeast, etc?"
>
> I realize this is my ignorance showing and I appreciate what guidance
> can be offered in return.
>
> Cheers, thanks.
>
> Chris Mears
> Charlottetown, PEI, Canada

Well, first make sure it's warm enough, most yeasts work better from
20 to 30C. Just adding yeast to a stuck fermentation usually ends up
in more wasted yeast. You are better off building a starter and
feeding it into the batch a bit at a time (pull off some of the batch
and add it to the starter, not the other way around).

Joe.

fermenting stuck
 

On Nov 23, 7:13 pm, "bobdrob" > wrote:
> hi chris & welcome... can you tell us please: what was yr starting SG &
> what yeast did you use? did you taking any other readings like TA or pH?
> also what else besides apples is in the 3 gals you've got going? You can
> always pitch more yeast...but that could just stall too. More info will
> allow your question to be answered more thoroughly. regards, bob

Hi. The recipe is just a basic apples+water+sugar+yeast (+nutrient,
campden, etc). I didn't take any extra readings when I put this one
together, but the initial SG was at 1100. The batch is about a month
and a half old and has been a very slow product so far - the slow bit
I'm not at all worried with. It's being kept in my pantry, so it is
at about room temperature all the time.
Cheers
Chris

fermenting stuck
 

>
> Well, first make sure it's warm enough, most yeasts work better from
> 20 to 30C. Just adding yeast to a stuck fermentation usually ends up
> in more wasted yeast. You are better off building a starter and
> feeding it into the batch a bit at a time (pull off some of the batch
> and add it to the starter, not the other way around).
>
> Joe.

Hi. Is there a special starter I should use to re-start this? Room
temperature shouldn't be an issue - it's being kept in my pantry so it
is always warm enough. In other news, I have a second lovely batch
that is working out well; it is clearing now and I am looking forward
to bottling it soon.
Cheers
Chris

fermenting stuck
 

"chrismears" > wrote in message
...
> On Nov 23, 7:13 pm, "bobdrob" > wrote:
>> hi chris & welcome... can you tell us please: what was yr starting SG
>> &
>> what yeast did you use? did you taking any other readings like TA or pH?
>> also what else besides apples is in the 3 gals you've got going? You can
>> always pitch more yeast...but that could just stall too. More info will
>> allow your question to be answered more thoroughly. regards, bob
>
> Hi. The recipe is just a basic apples+water+sugar+yeast (+nutrient,
> campden, etc). I didn't take any extra readings when I put this one
> together, but the initial SG was at 1100. The batch is about a month
> and a half old and has been a very slow product so far - the slow bit
> I'm not at all worried with. It's being kept in my pantry, so it is
> at about room temperature all the time.
> Cheers
> Chris

Uhhhm, if the original SG was 1.110, then your in the potential alky-hol
range of 20+ % , or as we like to refer to it, knockout juice! my cohorts &
i 've been making KO-J for a couple of years.Being in that range suggests
that yr yeasties gave it their all then gave up the ghost; if you're in that
range, restarting the yeast is an option that will involve propagating a
large, more alcohol tolerant batch to pitch & will take a few days to
accomplish. Alternatively, have you tasted it yet? If your culture partyed
itself into yeast-oblivion @ 20% potential alcohol, try it; it may have a
pleasant sweetness to it before it sends you down tipsy street. If this is
the case, fret no more- let it sit to clarify racking as usual, etc. We've
bottled 4 batches of incompletely fermented KO-J w/o a bottlebomb to date.
If that makes you nervous, then hit it w/ some potassium sorbate before
bottling. If you want to ferment to dryness, then start your yeast in about
a quart of non-sorbated juice. Once it gets going, add a cup of yr stuck
wine, let it culture & keep adding stuck winein 1-2 cup increments until you
get a vigorous & thriving gallon of yeast . Then pitch that... I like lalvin
1118 in KO-J settings. HTH

fermenting stuck
 

On Nov 24, 11:36 am, "bobdrob" > wrote:
> "chrismears" > wrote in message
>
> ...
>
> > On Nov 23, 7:13 pm, "bobdrob" > wrote:
> >> hi chris & welcome... can you tell us please: what was yr starting SG
> >> &
> >> what yeast did you use? did you taking any other readings like TA or pH?
> >> also what else besides apples is in the 3 gals you've got going? You can
> >> always pitch more yeast...but that could just stall too. More info will
> >> allow your question to be answered more thoroughly. regards, bob
>
> > Hi. The recipe is just a basic apples+water+sugar+yeast (+nutrient,
> > campden, etc). I didn't take any extra readings when I put this one
> > together, but the initial SG was at 1100. The batch is about a month
> > and a half old and has been a very slow product so far - the slow bit
> > I'm not at all worried with. It's being kept in my pantry, so it is
> > at about room temperature all the time.
> > Cheers
> > Chris
>
> Uhhhm, if the original SG was 1.110, then your in the potential alky-hol
> range of 20+ % , or as we like to refer to it, knockout juice! my cohorts &

Bobdrob, you might want to recheck your SG table. 1.100 SG is only
going to give you 13.4% alcohol, and 1.110 is 14.9%.

Chris, I had a stuck fermentation with some Peach I did a couple years
back. What I did to get it going was to prepare a new starter using
apple juice. Once that was going strong I add small amounts of the
stuck juice to this starter over the next three days until I had added
in the all the juice from the stuck fermentation. For the stuck
fermentation I used yeast that is good for restarting a stuck
fermentation. Options are Red Star Premier Curvee, Lalvin 43, Lalvin
EC-1118, Lalvin K1-V1116, etc. There are more listed at
http://winemaking.jackkeller.net/strains.asp. Also add some yeast
energizer per package directions to ensure a strong starter. If you
use dry yeast make sure to re-hydrate it properly before addiing it to
your starter.

Here are some other links you might find useful:
http://www.yobrew.co.uk/stuck.php
http://www.grapestompers.com/article...rmentation.htm

Good Luck,
Steve

fermenting stuck
 

> Hi. Is there a special starter I should use to re-start this? Room
> temperature shouldn't be an issue - it's being kept in my pantry so it
> is always warm enough.

Steve's post already gave you great advice and the correct value of
'potential alcohol' for 1.100SG. (My tables came from NBS so I know
they are right.) The only thing I would expand on is the amount of
time to give it to get going. Starters need to get going really well
before you add them to the total volume. I keep doubling the volume
of the starter and let it get back to fermenting strongly.

>13% ABV for an apple wine might be a little heavy duty; if this died at around 9 or 10 % I might be happy with that. I show that as 1.022 to 1.029 S.G.

bobdrob,
I show 1.115 as 19.3 % ABV; I have the book at home that probably
takes them higher; I have spreadsheet I made on my work PC. I can
email you the spreadsheet.

Joe

fermenting stuck
 

On Nov 24, 10:27 am, chrismears > wrote:
> On Nov 23, 7:13 pm, "bobdrob" > wrote:
>
> > hi chris & welcome... can you tell us please: what was yr starting SG &
> > what yeast did you use? did you taking any other readings like TA or pH?
> > also what else besides apples is in the 3 gals you've got going? You can
> > always pitch more yeast...but that could just stall too. More info will
> > allow your question to be answered more thoroughly. regards, bob
>
> Hi. The recipe is just a basic apples+water+sugar+yeast (+nutrient,
> campden, etc). I didn't take any extra readings when I put this one
> together, but the initial SG was at 1100. The batch is about a month
> and a half old and has been a very slow product so far - the slow bit
> I'm not at all worried with. It's being kept in my pantry, so it is
> at about room temperature all the time.
> Cheers
> Chris

For future reference, over a month at room temperature is too slow for
a healthy ferment, espically if there is still so much sugar left.
Most likely cause is there is not enough active yeast in the batch,
possibly also lack of nutrients. Definitely do a strong starter with a
new strong yeast and restart the ferment.

Pp

fermenting stuck
 

Joe Sallustio wrote:

>
>> Hi. Is there a special starter I should use to
>> re-start this? Room temperature shouldn't be
>> an issue - it's being kept in my pantry so it
>> is always warm enough.
>
> Steve's post already gave you great advice and
> the correct value of
> 'potential alcohol' for 1.100SG. (My tables
> came from NBS so I know
> they are right.) The only thing I would expand
> on is the amount of
> time to give it to get going. Starters need to
> get going really well
> before you add them to the total volume. I
> keep doubling the volume of the starter and let
> it get back to fermenting strongly.
>
>>13% ABV for an apple wine might be a little
>>heavy duty; if this died at around 9 or 10 % I
>>might be happy with that. I show that as 1.022
>>to 1.029 S.G.
>
> bobdrob,
> I show 1.115 as 19.3 % ABV; I have the book at
> home that probably
> takes them higher; I have spreadsheet I made on
> my work PC. I can email you the spreadsheet.
>
> Joe

Joe, are you sure of that? I quick check on my
program shows 1.115 SG to be equivalent to 15.78
Brix and the PA to be 15.78

fermenting stuck
 

On Nov 26, 11:46 am, "Paul E. Lehmann" > wrote:
> Joe Sallustio wrote:
>
> >> Hi. Is there a special starter I should use to
> >> re-start this? Room temperature shouldn't be
> >> an issue - it's being kept in my pantry so it
> >> is always warm enough.
>
> > Steve's post already gave you great advice and
> > the correct value of
> > 'potential alcohol' for 1.100SG. (My tables
> > came from NBS so I know
> > they are right.) The only thing I would expand
> > on is the amount of
> > time to give it to get going. Starters need to
> > get going really well
> > before you add them to the total volume. I
> > keep doubling the volume of the starter and let
> > it get back to fermenting strongly.
>
> >>13% ABV for an apple wine might be a little
> >>heavy duty; if this died at around 9 or 10 % I
> >>might be happy with that. I show that as 1.022
> >>to 1.029 S.G.
>
> > bobdrob,
> > I show 1.115 as 19.3 % ABV; I have the book at
> > home that probably
> > takes them higher; I have spreadsheet I made on
> > my work PC. I can email you the spreadsheet.
>
> > Joe
>
> Joe, are you sure of that? I quick check on my
> program shows 1.115 SG to be equivalent to 15.78
> Brix and the PA to be 15.78- Hide quoted text -
>
> - Show quoted text -

Same here - don't have the tables on me but last couple of years we
got some Zin and Petite Sirah grapes that were over 1.130. I remember
checking the PA on those and even that was definitely under 20% - not
that we fermented them that way!

Pp

fermenting stuck
 

I use this table: http://www.brsquared.org/wine/CalcInfo/HydSugAl.htm
which backs paul and joe's comments.

I have to admit though, I never quite understood how this can be if
0PA is 1.000 and I usually ferment down to around 0.990

Jim

On Nov 26, 8:36 pm, pp > wrote:
> On Nov 26, 11:46 am, "Paul E. Lehmann" > wrote:
>
>
>
> > Joe Sallustio wrote:
>
> > >> Hi. Is there a special starter I should use to
> > >> re-start this? Room temperature shouldn't be
> > >> an issue - it's being kept in my pantry so it
> > >> is always warm enough.
>
> > > Steve's post already gave you great advice and
> > > the correct value of
> > > 'potential alcohol' for 1.100SG. (My tables
> > > came from NBS so I know
> > > they are right.) The only thing I would expand
> > > on is the amount of
> > > time to give it to get going. Starters need to
> > > get going really well
> > > before you add them to the total volume. I
> > > keep doubling the volume of the starter and let
> > > it get back to fermenting strongly.
>
> > >>13% ABV for an apple wine might be a little
> > >>heavy duty; if this died at around 9 or 10 % I
> > >>might be happy with that. I show that as 1.022
> > >>to 1.029 S.G.
>
> > > bobdrob,
> > > I show 1.115 as 19.3 % ABV; I have the book at
> > > home that probably
> > > takes them higher; I have spreadsheet I made on
> > > my work PC. I can email you the spreadsheet.
>
> > > Joe
>
> > Joe, are you sure of that? I quick check on my
> > program shows 1.115 SG to be equivalent to 15.78
> > Brix and the PA to be 15.78- Hide quoted text -
>
> > - Show quoted text -
>
> Same here - don't have the tables on me but last couple of years we
> got some Zin and Petite Sirah grapes that were over 1.130. I remember
> checking the PA on those and even that was definitely under 20% - not
> that we fermented them that way!
>
> Pp

fermenting stuck
 

Why is everybody calling me Joe these days? :-p

As for the 0.990 vs 1.000 difference, basically, you can think about
it as the table being designed so that instead of using the difference
between the starting and final sg points, you're only using the
starting point. In other words, the table is built with the assumption
that your wine ferments completely to dryness (because that's what PA
means) and gives you the PA values with that assumption.

Pp

On Nov 26, 1:37 pm, jim > wrote:
> I use this table:http://www.brsquared.org/wine/CalcInfo/HydSugAl.htm
> which backs paul and joe's comments.
>
> I have to admit though, I never quite understood how this can be if
> 0PA is 1.000 and I usually ferment down to around 0.990
>
> Jim
>
> On Nov 26, 8:36 pm, pp > wrote:
>
>
>
> > On Nov 26, 11:46 am, "Paul E. Lehmann" > wrote:
>
> > > Joe Sallustio wrote:
>
> > > >> Hi. Is there a special starter I should use to
> > > >> re-start this? Room temperature shouldn't be
> > > >> an issue - it's being kept in my pantry so it
> > > >> is always warm enough.
>
> > > > Steve's post already gave you great advice and
> > > > the correct value of
> > > > 'potential alcohol' for 1.100SG. (My tables
> > > > came from NBS so I know
> > > > they are right.) The only thing I would expand
> > > > on is the amount of
> > > > time to give it to get going. Starters need to
> > > > get going really well
> > > > before you add them to the total volume. I
> > > > keep doubling the volume of the starter and let
> > > > it get back to fermenting strongly.
>
> > > >>13% ABV for an apple wine might be a little
> > > >>heavy duty; if this died at around 9 or 10 % I
> > > >>might be happy with that. I show that as 1.022
> > > >>to 1.029 S.G.
>
> > > > bobdrob,
> > > > I show 1.115 as 19.3 % ABV; I have the book at
> > > > home that probably
> > > > takes them higher; I have spreadsheet I made on
> > > > my work PC. I can email you the spreadsheet.
>
> > > > Joe
>
> > > Joe, are you sure of that? I quick check on my
> > > program shows 1.115 SG to be equivalent to 15.78
> > > Brix and the PA to be 15.78- Hide quoted text -
>
> > > - Show quoted text -
>
> > Same here - don't have the tables on me but last couple of years we
> > got some Zin and Petite Sirah grapes that were over 1.130. I remember
> > checking the PA on those and even that was definitely under 20% - not
> > that we fermented them that way!
>
> > Pp- Hide quoted text -
>
> - Show quoted text -

fermenting stuck
 

Heh sorry to miss you out. Thanks for the info.

I understand that PA starts with the potential. What I am getting at
is that SG and PA are given a common correlation as being discussed in
this thread. Yet, SG works on total movement (from initial to final
SG). So, what is the difference between a wine with PA of 15 that
finishes at SG 1.000 and a wine with a PA of 15 which finishes at
0.990?

That still *weirds me out* Many thanks and I hope this isn't too off
topic.

Jim

On Nov 27, 1:04 am, pp > wrote:
> Why is everybody calling me Joe these days? :-p
>
> As for the 0.990 vs 1.000 difference, basically, you can think about
> it as the table being designed so that instead of using the difference
> between the starting and final sg points, you're only using the
> starting point. In other words, the table is built with the assumption
> that your wine ferments completely to dryness (because that's what PA
> means) and gives you the PA values with that assumption.
>
> Pp
>
> On Nov 26, 1:37 pm, jim > wrote:
>
> > I use this table:http://www.brsquared.org/wine/CalcInfo/HydSugAl.htm
> > which backs paul and joe's comments.
>
> > I have to admit though, I never quite understood how this can be if
> > 0PA is 1.000 and I usually ferment down to around 0.990
>
> > Jim
>
> > On Nov 26, 8:36 pm, pp > wrote:
>
> > > On Nov 26, 11:46 am, "Paul E. Lehmann" > wrote:
>
> > > > Joe Sallustio wrote:
>
> > > > >> Hi. Is there a special starter I should use to
> > > > >> re-start this? Room temperature shouldn't be
> > > > >> an issue - it's being kept in my pantry so it
> > > > >> is always warm enough.
>
> > > > > Steve's post already gave you great advice and
> > > > > the correct value of
> > > > > 'potential alcohol' for 1.100SG. (My tables
> > > > > came from NBS so I know
> > > > > they are right.) The only thing I would expand
> > > > > on is the amount of
> > > > > time to give it to get going. Starters need to
> > > > > get going really well
> > > > > before you add them to the total volume. I
> > > > > keep doubling the volume of the starter and let
> > > > > it get back to fermenting strongly.
>
> > > > >>13% ABV for an apple wine might be a little
> > > > >>heavy duty; if this died at around 9 or 10 % I
> > > > >>might be happy with that. I show that as 1.022
> > > > >>to 1.029 S.G.
>
> > > > > bobdrob,
> > > > > I show 1.115 as 19.3 % ABV; I have the book at
> > > > > home that probably
> > > > > takes them higher; I have spreadsheet I made on
> > > > > my work PC. I can email you the spreadsheet.
>
> > > > > Joe
>
> > > > Joe, are you sure of that? I quick check on my
> > > > program shows 1.115 SG to be equivalent to 15.78
> > > > Brix and the PA to be 15.78- Hide quoted text -
>
> > > > - Show quoted text -
>
> > > Same here - don't have the tables on me but last couple of years we
> > > got some Zin and Petite Sirah grapes that were over 1.130. I remember
> > > checking the PA on those and even that was definitely under 20% - not
> > > that we fermented them that way!
>
> > > Pp- Hide quoted text -
>
> > - Show quoted text -

fermenting stuck
 

jim wrote:

> Heh sorry to miss you out. Thanks for the info.
>
> I understand that PA starts with the potential.
> What I am getting at is that SG and PA are given
> a common correlation as being discussed in
> this thread. Yet, SG works on total movement
> (from initial to final
> SG). So, what is the difference between a wine
> with PA of 15 that finishes at SG 1.000 and a
> wine with a PA of 15 which finishes at 0.990?
>
> That still *weirds me out* Many thanks and I
> hope this isn't too off topic.

Ray Calvert had a discussion on this point about a
year ago with another poster. I don't think it
was ever resolved.

In my calculations I use formulae that were
developed by UC Davis. Of course, this does not
mean that they are bullet proof.

In order to resolve this, I think someone (who
actually cares enough - or is interested enough)
to actually do an experiment and ferment a wine
with a known initial SG and a final SG (both
corrected for temperature - preferably with a
high initial SG and a very low final SG) and send
the finished wine to a certified lab for results
of PA. The test is not all that expensive,
especially considering all the controversy about
the topic.



>
> Jim
>
> On Nov 27, 1:04 am, pp >
> wrote:
>> Why is everybody calling me Joe these days? :-p
>>
>> As for the 0.990 vs 1.000 difference,
>> basically, you can think about it as the table
>> being designed so that instead of using the
>> difference between the starting and final sg
>> points, you're only using the starting point.
>> In other words, the table is built with the
>> assumption that your wine ferments completely
>> to dryness (because that's what PA means) and
>> gives you the PA values with that assumption.
>>
>> Pp
>>
>> On Nov 26, 1:37 pm, jim >
>> wrote:
>>
>> > I use this
>> >
table:http://www.brsquared.org/wine/CalcInfo/HydSugAl.htm
>> > which backs paul and joe's comments.
>>
>> > I have to admit though, I never quite
>> > understood how this can be if 0PA is 1.000
>> > and I usually ferment down to around 0.990
>>
>> > Jim
>>
>> > On Nov 26, 8:36 pm, pp >
>> > wrote:
>>
>> > > On Nov 26, 11:46 am, "Paul E. Lehmann"
>> > > > wrote:
>>
>> > > > Joe Sallustio wrote:
>>
>> > > > >> Hi. Is there a special starter I
>> > > > >> should use to
>> > > > >> re-start this? Room temperature
>> > > > >> shouldn't be an issue - it's being
>> > > > >> kept in my pantry so it is always warm
>> > > > >> enough.
>>
>> > > > > Steve's post already gave you great
>> > > > > advice and the correct value of
>> > > > > 'potential alcohol' for 1.100SG. (My
>> > > > > tables came from NBS so I know
>> > > > > they are right.) The only thing I
>> > > > > would expand on is the amount of
>> > > > > time to give it to get going. Starters
>> > > > > need to get going really well
>> > > > > before you add them to the total
>> > > > > volume. I keep doubling the volume of
>> > > > > the starter and let it get back to
>> > > > > fermenting strongly.
>>
>> > > > >>13% ABV for an apple wine might be a
>> > > > >>little heavy duty; if this died at
>> > > > >>around 9 or 10 % I
>> > > > >>might be happy with that. I show that
>> > > > >>as 1.022 to 1.029 S.G.
>>
>> > > > > bobdrob,
>> > > > > I show 1.115 as 19.3 % ABV; I have the
>> > > > > book at home that probably
>> > > > > takes them higher; I have spreadsheet I
>> > > > > made on
>> > > > > my work PC. I can email you the
>> > > > > spreadsheet.
>>
>> > > > > Joe
>>
>> > > > Joe, are you sure of that? I quick check
>> > > > on my program shows 1.115 SG to be
>> > > > equivalent to 15.78 Brix and the PA to be
>> > > > 15.78- Hide quoted text -
>>
>> > > > - Show quoted text -
>>
>> > > Same here - don't have the tables on me but
>> > > last couple of years we got some Zin and
>> > > Petite Sirah grapes that were over 1.130. I
>> > > remember checking the PA on those and even
>> > > that was definitely under 20% - not that we
>> > > fermented them that way!
>>
>> > > Pp- Hide quoted text -
>>
>> > - Show quoted text -

fermenting stuck
 

The final SG of a wine fermented to dryness has to account for the fact
that the alcohol in the wine is less dense than water. That's why the
dry wine has an SG less than 1.000. A wine at SG 1.000 is not quite dry.

Gene

jim wrote:
> Heh sorry to miss you out. Thanks for the info.
>
> I understand that PA starts with the potential. What I am getting at
> is that SG and PA are given a common correlation as being discussed in
> this thread. Yet, SG works on total movement (from initial to final
> SG). So, what is the difference between a wine with PA of 15 that
> finishes at SG 1.000 and a wine with a PA of 15 which finishes at
> 0.990?
>
> That still *weirds me out* Many thanks and I hope this isn't too off
> topic.
>
> Jim
>
> On Nov 27, 1:04 am, pp > wrote:
>> Why is everybody calling me Joe these days? :-p
>>
>> As for the 0.990 vs 1.000 difference, basically, you can think about
>> it as the table being designed so that instead of using the difference
>> between the starting and final sg points, you're only using the
>> starting point. In other words, the table is built with the assumption
>> that your wine ferments completely to dryness (because that's what PA
>> means) and gives you the PA values with that assumption.
>>
>> Pp
>>
>> On Nov 26, 1:37 pm, jim > wrote:
>>
>>> I use this table:http://www.brsquared.org/wine/CalcInfo/HydSugAl.htm
>>> which backs paul and joe's comments.
>>> I have to admit though, I never quite understood how this can be if
>>> 0PA is 1.000 and I usually ferment down to around 0.990
>>> Jim
>>> On Nov 26, 8:36 pm, pp > wrote:
>>>> On Nov 26, 11:46 am, "Paul E. Lehmann" > wrote:
>>>>> Joe Sallustio wrote:
>>>>>>> Hi. Is there a special starter I should use to
>>>>>>> re-start this? Room temperature shouldn't be
>>>>>>> an issue - it's being kept in my pantry so it
>>>>>>> is always warm enough.
>>>>>> Steve's post already gave you great advice and
>>>>>> the correct value of
>>>>>> 'potential alcohol' for 1.100SG. (My tables
>>>>>> came from NBS so I know
>>>>>> they are right.) The only thing I would expand
>>>>>> on is the amount of
>>>>>> time to give it to get going. Starters need to
>>>>>> get going really well
>>>>>> before you add them to the total volume. I
>>>>>> keep doubling the volume of the starter and let
>>>>>> it get back to fermenting strongly.
>>>>>>> 13% ABV for an apple wine might be a little
>>>>>>> heavy duty; if this died at around 9 or 10 % I
>>>>>>> might be happy with that. I show that as 1.022
>>>>>>> to 1.029 S.G.
>>>>>> bobdrob,
>>>>>> I show 1.115 as 19.3 % ABV; I have the book at
>>>>>> home that probably
>>>>>> takes them higher; I have spreadsheet I made on
>>>>>> my work PC. I can email you the spreadsheet.
>>>>>> Joe
>>>>> Joe, are you sure of that? I quick check on my
>>>>> program shows 1.115 SG to be equivalent to 15.78
>>>>> Brix and the PA to be 15.78- Hide quoted text -
>>>>> - Show quoted text -
>>>> Same here - don't have the tables on me but last couple of years we
>>>> got some Zin and Petite Sirah grapes that were over 1.130. I remember
>>>> checking the PA on those and even that was definitely under 20% - not
>>>> that we fermented them that way!
>>>> Pp- Hide quoted text -
>>> - Show quoted text -
>

fermenting stuck
 

my lexdyksic abinility to dear a dryhometer notwithstanding, i'd appreciate
a copy of that spreadsheet. thanks joe!



"Joe Sallustio" > wrote in message
...
>
>> Hi. Is there a special starter I should use to re-start this? Room
>> temperature shouldn't be an issue - it's being kept in my pantry so it
>> is always warm enough.
>
> Steve's post already gave you great advice and the correct value of
> 'potential alcohol' for 1.100SG. (My tables came from NBS so I know
> they are right.) The only thing I would expand on is the amount of
> time to give it to get going. Starters need to get going really well
> before you add them to the total volume. I keep doubling the volume
> of the starter and let it get back to fermenting strongly.
>
>>13% ABV for an apple wine might be a little heavy duty; if this died at
>>around 9 or 10 % I might be happy with that. I show that as 1.022 to
>>1.029 S.G.
>
> bobdrob,
> I show 1.115 as 19.3 % ABV; I have the book at home that probably
> takes them higher; I have spreadsheet I made on my work PC. I can
> email you the spreadsheet.
>
> Joe

fermenting stuck
 

Hi Gene, alcohol is definitely less dense than water, but if a wine at
1.000 is not quite dry, why do they calibrate 1.000 with 0PA? Do you
see why I think it is confusing?

Jim

On Nov 27, 9:34 am, gene > wrote:
> The final SG of a wine fermented to dryness has to account for the fact
> that the alcohol in the wine is less dense than water. That's why the
> dry wine has an SG less than 1.000. A wine at SG 1.000 is not quite dry.
>
> Gene
>
> jim wrote:
> > Heh sorry to miss you out. Thanks for the info.
>
> > I understand that PA starts with the potential. What I am getting at
> > is that SG and PA are given a common correlation as being discussed in
> > this thread. Yet, SG works on total movement (from initial to final
> > SG). So, what is the difference between a wine with PA of 15 that
> > finishes at SG 1.000 and a wine with a PA of 15 which finishes at
> > 0.990?
>
> > That still *weirds me out* Many thanks and I hope this isn't too off
> > topic.
>
> > Jim
>
> > On Nov 27, 1:04 am, pp > wrote:
> >> Why is everybody calling me Joe these days? :-p
>
> >> As for the 0.990 vs 1.000 difference, basically, you can think about
> >> it as the table being designed so that instead of using the difference
> >> between the starting and final sg points, you're only using the
> >> starting point. In other words, the table is built with the assumption
> >> that your wine ferments completely to dryness (because that's what PA
> >> means) and gives you the PA values with that assumption.
>
> >> Pp
>
> >> On Nov 26, 1:37 pm, jim > wrote:
>
> >>> I use this table:http://www.brsquared.org/wine/CalcInfo/HydSugAl.htm
> >>> which backs paul and joe's comments.
> >>> I have to admit though, I never quite understood how this can be if
> >>> 0PA is 1.000 and I usually ferment down to around 0.990
> >>> Jim
> >>> On Nov 26, 8:36 pm, pp > wrote:
> >>>> On Nov 26, 11:46 am, "Paul E. Lehmann" > wrote:
> >>>>> Joe Sallustio wrote:
> >>>>>>> Hi. Is there a special starter I should use to
> >>>>>>> re-start this? Room temperature shouldn't be
> >>>>>>> an issue - it's being kept in my pantry so it
> >>>>>>> is always warm enough.
> >>>>>> Steve's post already gave you great advice and
> >>>>>> the correct value of
> >>>>>> 'potential alcohol' for 1.100SG. (My tables
> >>>>>> came from NBS so I know
> >>>>>> they are right.) The only thing I would expand
> >>>>>> on is the amount of
> >>>>>> time to give it to get going. Starters need to
> >>>>>> get going really well
> >>>>>> before you add them to the total volume. I
> >>>>>> keep doubling the volume of the starter and let
> >>>>>> it get back to fermenting strongly.
> >>>>>>> 13% ABV for an apple wine might be a little
> >>>>>>> heavy duty; if this died at around 9 or 10 % I
> >>>>>>> might be happy with that. I show that as 1.022
> >>>>>>> to 1.029 S.G.
> >>>>>> bobdrob,
> >>>>>> I show 1.115 as 19.3 % ABV; I have the book at
> >>>>>> home that probably
> >>>>>> takes them higher; I have spreadsheet I made on
> >>>>>> my work PC. I can email you the spreadsheet.
> >>>>>> Joe
> >>>>> Joe, are you sure of that? I quick check on my
> >>>>> program shows 1.115 SG to be equivalent to 15.78
> >>>>> Brix and the PA to be 15.78- Hide quoted text -
> >>>>> - Show quoted text -
> >>>> Same here - don't have the tables on me but last couple of years we
> >>>> got some Zin and Petite Sirah grapes that were over 1.130. I remember
> >>>> checking the PA on those and even that was definitely under 20% - not
> >>>> that we fermented them that way!
> >>>> Pp- Hide quoted text -
> >>> - Show quoted text -

fermenting stuck
 

On Nov 26, 2:46 pm, "Paul E. Lehmann" > wrote:
> Joe Sallustio wrote:
>
> >> Hi. Is there a special starter I should use to
> >> re-start this? Room temperature shouldn't be
> >> an issue - it's being kept in my pantry so it
> >> is always warm enough.
>
> > Steve's post already gave you great advice and
> > the correct value of
> > 'potential alcohol' for 1.100SG. (My tables
> > came from NBS so I know
> > they are right.) The only thing I would expand
> > on is the amount of
> > time to give it to get going. Starters need to
> > get going really well
> > before you add them to the total volume. I
> > keep doubling the volume of the starter and let
> > it get back to fermenting strongly.
>
> >>13% ABV for an apple wine might be a little
> >>heavy duty; if this died at around 9 or 10 % I
> >>might be happy with that. I show that as 1.022
> >>to 1.029 S.G.
>
> > bobdrob,
> > I show 1.115 as 19.3 % ABV; I have the book at
> > home that probably
> > takes them higher; I have spreadsheet I made on
> > my work PC. I can email you the spreadsheet.
>
> > Joe
>
> Joe, are you sure of that? I quick check on my
> program shows 1.115 SG to be equivalent to 15.78
> Brix and the PA to be 15.78

Hi Paul,
Yes, I'm sure to a rounding error. I have the book now. Baume
(modulus 145) is what most people refer to as 'potential alcohol'. I
show 34.3 brix =1.14985 S.G. =18.90 Baume 145 at 20C.

I really think the confusion comes from two places.

One, alcohol concentrations can be measured by volume (V/V or ABV) or
weight ABW) . Most refer to ABV now and don't mention ABW. ABW is
about 20% lower than ABV so maybe that is what your chart is
calibrated to, weight, not volume.

More important, the potential alcohol scale is _exactly_ what it says
it is. It is only a crude measuurement of potential alcohol. There
in no way to measure density changes and categorically align them to
actual alcohol content with precision. The type and quantity of yeast
used, the temperature of fermentation and the storage conditions all
play into final alcohol content. PA does not consider dry extract
content either, most of which is acid and is variable to an easily
measurable degree. It can't. Wine can have a little acetic acid and
can have a whole lot, that affects the density too.

All that said, if you make the same wines the same way with the same
materials you can probably predict pretty well what your final alcohol
will be. I use those values as a rough guess of where things stand
and that is it. As I see it, this scale is useful to monitor
fermentation progress and very little else because then is a
marginally relative measurement. Even then the acids are changing to
a measurable degree and all my hydrometers measure is total density at
a given temperature.

As to why it doesn't go below zero, I'm pretty sure Baume calibrated
his scales with salt solutions so by definition they can't go below
zero. The final gravity is much affected by dry extract content so
where a dry wine will end up isn't just a matter of alcohol, it's the
acid content and other dissolved solids too. The best relatively
cheap way to measure alcohol is by distillation and hydrometry; that
way you are measuring relatively pure components. The best cheap way
to measure residual sugar is Clinitest tablets.

Physics is cool but I treat the PA scale like Myth Busters; I watch it
but I don't lend a lot of weight to it... :)

Joe

fermenting stuck
 

Joe Sallustio wrote:

> On Nov 26, 2:46 pm, "Paul E. Lehmann"
> > wrote:
>> Joe Sallustio wrote:
>>
>> >> Hi. Is there a special starter I should use
>> >> to
>> >> re-start this? Room temperature shouldn't
>> >> be an issue - it's being kept in my pantry
>> >> so it is always warm enough.
>>
>> > Steve's post already gave you great advice
>> > and the correct value of
>> > 'potential alcohol' for 1.100SG. (My tables
>> > came from NBS so I know
>> > they are right.) The only thing I would
>> > expand on is the amount of
>> > time to give it to get going. Starters need
>> > to get going really well
>> > before you add them to the total volume. I
>> > keep doubling the volume of the starter and
>> > let it get back to fermenting strongly.
>>
>> >>13% ABV for an apple wine might be a little
>> >>heavy duty; if this died at around 9 or 10 %
>> >>I
>> >>might be happy with that. I show that as
>> >>1.022 to 1.029 S.G.
>>
>> > bobdrob,
>> > I show 1.115 as 19.3 % ABV; I have the book
>> > at home that probably
>> > takes them higher; I have spreadsheet I made
>> > on
>> > my work PC. I can email you the spreadsheet.
>>
>> > Joe
>>
>> Joe, are you sure of that? I quick check on my
>> program shows 1.115 SG to be equivalent to
>> 15.78 Brix and the PA to be 15.78
>
> Hi Paul,
> Yes, I'm sure to a rounding error. I have the
> book now. Baume
> (modulus 145) is what most people refer to as
> 'potential alcohol'. I show 34.3 brix =1.14985
> S.G. =18.90 Baume 145 at 20C.
>
> I really think the confusion comes from two
> places.
>
> One, alcohol concentrations can be measured by
> volume (V/V or ABV) or
> weight ABW) . Most refer to ABV now and don't
> mention ABW. ABW is about 20% lower than ABV so
> maybe that is what your chart is calibrated to,
> weight, not volume.
>
> More important, the potential alcohol scale is
> _exactly_ what it says
> it is. It is only a crude measuurement of
> potential alcohol. There in no way to measure
> density changes and categorically align them to
> actual alcohol content with precision. The type
> and quantity of yeast
> used, the temperature of fermentation and the
> storage conditions all
> play into final alcohol content. PA does not
> consider dry extract content either, most of
> which is acid and is variable to an easily
> measurable degree. It can't. Wine can have a
> little acetic acid and can have a whole lot,
> that affects the density too.
>
> All that said, if you make the same wines the
> same way with the same materials you can
> probably predict pretty well what your final
> alcohol
> will be. I use those values as a rough guess of
> where things stand
> and that is it. As I see it, this scale is
> useful to monitor fermentation progress and very
> little else because then is a
> marginally relative measurement. Even then the
> acids are changing to a measurable degree and
> all my hydrometers measure is total density at a
> given temperature.
>
> As to why it doesn't go below zero, I'm pretty
> sure Baume calibrated his scales with salt
> solutions so by definition they can't go below
> zero. The final gravity is much affected by dry
> extract content so where a dry wine will end up
> isn't just a matter of alcohol, it's the
> acid content and other dissolved solids too.
> The best relatively cheap way to measure alcohol
> is by distillation and hydrometry; that
> way you are measuring relatively pure
> components. The best cheap way to measure
> residual sugar is Clinitest tablets.
>
> Physics is cool but I treat the PA scale like
> Myth Busters; I watch it
> but I don't lend a lot of weight to it... :)
>
> Joe

Just curious, what does your book say the PA and
SG equivalent to 22 Brix is?

Personally, I am not hung up on Alcohol. In fact
I very much dislike the high Brix Central Valley
California wines. I much more prefer the lower
alcohol Mid Atlantic wines. They go a lot better
with food. I guess that is why they are called
"old style" wines.

fermenting stuck
 

On Nov 27, 4:10 am, Joe Sallustio > wrote:
> On Nov 26, 2:46 pm, "Paul E. Lehmann" > wrote:
>
>
>
>
>
> > Joe Sallustio wrote:
>
> > >> Hi. Is there a special starter I should use to
> > >> re-start this? Room temperature shouldn't be
> > >> an issue - it's being kept in my pantry so it
> > >> is always warm enough.
>
> > > Steve's post already gave you great advice and
> > > the correct value of
> > > 'potential alcohol' for 1.100SG. (My tables
> > > came from NBS so I know
> > > they are right.) The only thing I would expand
> > > on is the amount of
> > > time to give it to get going. Starters need to
> > > get going really well
> > > before you add them to the total volume. I
> > > keep doubling the volume of the starter and let
> > > it get back to fermenting strongly.
>
> > >>13% ABV for an apple wine might be a little
> > >>heavy duty; if this died at around 9 or 10 % I
> > >>might be happy with that. I show that as 1.022
> > >>to 1.029 S.G.
>
> > > bobdrob,
> > > I show 1.115 as 19.3 % ABV; I have the book at
> > > home that probably
> > > takes them higher; I have spreadsheet I made on
> > > my work PC. I can email you the spreadsheet.
>
> > > Joe
>
> > Joe, are you sure of that? I quick check on my
> > program shows 1.115 SG to be equivalent to 15.78
> > Brix and the PA to be 15.78
>
> Hi Paul,
> Yes, I'm sure to a rounding error. I have the book now. Baume
> (modulus 145) is what most people refer to as 'potential alcohol'. I
> show 34.3 brix =1.14985 S.G. =18.90 Baume 145 at 20C.
>

Okay, that explains it - Joe, I think you're missing a "1" in the
second decimal point, so we're comparing sg of 1.11 against that of
1.15, which would account for the large discrepancy in the calculated
alcohol value.

Pp

fermenting stuck
 

On Nov 27, 2:30 am, jim > wrote:
> Hi Gene, alcohol is definitely less dense than water, but if a wine at
> 1.000 is not quite dry, why do they calibrate 1.000 with 0PA? Do you
> see why I think it is confusing?
>
> Jim
>

Because when you have a wine with sg of 1.000, you're talking about a
final gravity reading, after fermentation. The PA table, on the other
hand talks about the starting gravity of the must. The PA tables are
usually calibrated for a water-sugar solution and 1.000 is the sg
point of water, so "must" of 1.000 by definition contains no sugar so
it has PA of 0%.

Pp

fermenting stuck
 

My understanding is the SG 1.000 is calibrated with distilled water at
20 degC (68 degF).

Zero PA (0PA) is a stable reference point, though it doesn't reflect the
true zero PA density of grape must. About 5-10 percent of the total
soluble solids in the grape must are from non-fermentable sugars,
organic acids, organic acid salts, nitrogen-containing compounds,
tannins, pectins and mineral salts.

These other soluble solids are responsible for a lot of the uncertainty
in PA calculation from must SG. Alcohol evaporation during fermentation
is the other significant variable making PA an inexact predictor of
final alcohol content.

I found the following reference about grape maturity useful for getting
a good picture of the grape growing practices and analyses on winemaking
results.
http://winegrapes.tamu.edu/grow/maturity.pdf

One topic they discuss is potential alcohol.

Gene



jim wrote:
> Hi Gene, alcohol is definitely less dense than water, but if a wine at
> 1.000 is not quite dry, why do they calibrate 1.000 with 0PA? Do you
> see why I think it is confusing?
>
> Jim
>
> On Nov 27, 9:34 am, gene > wrote:
>> The final SG of a wine fermented to dryness has to account for the fact
>> that the alcohol in the wine is less dense than water. That's why the
>> dry wine has an SG less than 1.000. A wine at SG 1.000 is not quite dry.
>>
>> Gene
>>
>> jim wrote:
>>> Heh sorry to miss you out. Thanks for the info.
>>> I understand that PA starts with the potential. What I am getting at
>>> is that SG and PA are given a common correlation as being discussed in
>>> this thread. Yet, SG works on total movement (from initial to final
>>> SG). So, what is the difference between a wine with PA of 15 that
>>> finishes at SG 1.000 and a wine with a PA of 15 which finishes at
>>> 0.990?
>>> That still *weirds me out* Many thanks and I hope this isn't too off
>>> topic.
>>> Jim
>>> On Nov 27, 1:04 am, pp > wrote:
>>>> Why is everybody calling me Joe these days? :-p
>>>> As for the 0.990 vs 1.000 difference, basically, you can think about
>>>> it as the table being designed so that instead of using the difference
>>>> between the starting and final sg points, you're only using the
>>>> starting point. In other words, the table is built with the assumption
>>>> that your wine ferments completely to dryness (because that's what PA
>>>> means) and gives you the PA values with that assumption.
>>>> Pp
>>>> On Nov 26, 1:37 pm, jim > wrote:
>>>>> I use this table:http://www.brsquared.org/wine/CalcInfo/HydSugAl.htm
>>>>> which backs paul and joe's comments.
>>>>> I have to admit though, I never quite understood how this can be if
>>>>> 0PA is 1.000 and I usually ferment down to around 0.990
>>>>> Jim
>>>>> On Nov 26, 8:36 pm, pp > wrote:
>>>>>> On Nov 26, 11:46 am, "Paul E. Lehmann" > wrote:
>>>>>>> Joe Sallustio wrote:
>>>>>>>>> Hi. Is there a special starter I should use to
>>>>>>>>> re-start this? Room temperature shouldn't be
>>>>>>>>> an issue - it's being kept in my pantry so it
>>>>>>>>> is always warm enough.
>>>>>>>> Steve's post already gave you great advice and
>>>>>>>> the correct value of
>>>>>>>> 'potential alcohol' for 1.100SG. (My tables
>>>>>>>> came from NBS so I know
>>>>>>>> they are right.) The only thing I would expand
>>>>>>>> on is the amount of
>>>>>>>> time to give it to get going. Starters need to
>>>>>>>> get going really well
>>>>>>>> before you add them to the total volume. I
>>>>>>>> keep doubling the volume of the starter and let
>>>>>>>> it get back to fermenting strongly.
>>>>>>>>> 13% ABV for an apple wine might be a little
>>>>>>>>> heavy duty; if this died at around 9 or 10 % I
>>>>>>>>> might be happy with that. I show that as 1.022
>>>>>>>>> to 1.029 S.G.
>>>>>>>> bobdrob,
>>>>>>>> I show 1.115 as 19.3 % ABV; I have the book at
>>>>>>>> home that probably
>>>>>>>> takes them higher; I have spreadsheet I made on
>>>>>>>> my work PC. I can email you the spreadsheet.
>>>>>>>> Joe
>>>>>>> Joe, are you sure of that? I quick check on my
>>>>>>> program shows 1.115 SG to be equivalent to 15.78
>>>>>>> Brix and the PA to be 15.78- Hide quoted text -
>>>>>>> - Show quoted text -
>>>>>> Same here - don't have the tables on me but last couple of years we
>>>>>> got some Zin and Petite Sirah grapes that were over 1.130. I remember
>>>>>> checking the PA on those and even that was definitely under 20% - not
>>>>>> that we fermented them that way!
>>>>>> Pp- Hide quoted text -
>>>>> - Show quoted text -
>

fermenting stuck
 

"jim" > wrote in message
...
> Hi Gene, alcohol is definitely less dense than water, but if a wine at
> 1.000 is not quite dry, why do they calibrate 1.000 with 0PA? Do you
> see why I think it is confusing?
>
> Jim

The scales on a hydrometer are like a snapshot. A picture of a
moment frozen in time. That picture is of a prepitch must with
no alcohol in it. Once alcohol enters the picture, the claibration
on the hydrometer is no longer valid. HTH

Frederick

fermenting stuck
 

On Nov 28, 12:00 pm, "frederick ploegman" >
wrote:
> "jim" > wrote in message
>
> ...
>
> > Hi Gene, alcohol is definitely less dense than water, but if a wine at
> > 1.000 is not quite dry, why do they calibrate 1.000 with 0PA? Do you
> > see why I think it is confusing?
>
> > Jim
>
> The scales on a hydrometer are like a snapshot. A picture of a
> moment frozen in time. That picture is of a prepitch must with
> no alcohol in it. Once alcohol enters the picture, the claibration
> on the hydrometer is no longer valid. HTH
>
> Frederick

Now that makes it all coherent for me, thanks Frederick!

fermenting stuck
 

jim wrote:
> On Nov 28, 12:00 pm, "frederick ploegman" >
> wrote:
>> "jim" > wrote in message
>>
>> ...
>>
>>> Hi Gene, alcohol is definitely less dense than water, but if a wine at
>>> 1.000 is not quite dry, why do they calibrate 1.000 with 0PA? Do you
>>> see why I think it is confusing?
>>> Jim
>> The scales on a hydrometer are like a snapshot. A picture of a
>> moment frozen in time. That picture is of a prepitch must with
>> no alcohol in it. Once alcohol enters the picture, the claibration
>> on the hydrometer is no longer valid. HTH
>>
>> Frederick
>
> Now that makes it all coherent for me, thanks Frederick!

Are you sure about that, Frederick?

My understanding is that alcohol doesn't affect the Specific Gravity
accuracy, but it does affect the correlation to "potential alcohol" and
"degrees Brix". The more alcohol, the bigger the skew error.

I'm aware of only three significant factors that cause errors in
specific gravity measurement of wine with a properly calibrated hydrometer.

First, bubbles in the solution cause buoyancy errors (that's why we spin
the hydrometer, to knock bubbles off of it). Second, suspended solids
(floating grape skins, etc.) which, if touching the hydrometer, cause
buoyancy errors. Third is temperature of the juice, for which we have
SG correction tables.

Am I missing something here?

Gene

fermenting stuck
 

"gene" > wrote in message
t...
> jim wrote:
>> On Nov 28, 12:00 pm, "frederick ploegman" >
>> wrote:
>>> "jim" > wrote in message
>>>
>>> ...
>>>
>>>> Hi Gene, alcohol is definitely less dense than water, but if a wine at
>>>> 1.000 is not quite dry, why do they calibrate 1.000 with 0PA? Do you
>>>> see why I think it is confusing?
>>>> Jim
>>> The scales on a hydrometer are like a snapshot. A picture of a
>>> moment frozen in time. That picture is of a prepitch must with
>>> no alcohol in it. Once alcohol enters the picture, the claibration
>>> on the hydrometer is no longer valid. HTH
>>>
>>> Frederick
>>
>> Now that makes it all coherent for me, thanks Frederick!
>
> Are you sure about that, Frederick?
>
> My understanding is that alcohol doesn't affect the Specific Gravity
> accuracy, but it does affect the correlation to "potential alcohol" and
> "degrees Brix". The more alcohol, the bigger the skew error.
>

<snip>

Yup - that's what I meant. Jim's question was about the relationship
between SG and PA and alcohol definitely "skews" that up. ;o)

Frederick

fermenting stuck
 

Apples and pears contain sorbitol which give them nonfermentable
gravity. The effect you describe does occasionally occur with some
varietys of pears. Apples the effect is always present but is
ususually quite low.
Stuck ferments on apple is sometimes due to zinc deficiency Years ago
I used to add twenty grams of zinc sulphate and five grams of thiamine
to twenty five thousand litres of ferment this was enough in most
cases to unstick a stuck ferment.

Bob M
www.molab.co.nz

fermenting stuck
 

Hi. It's been a while since I participated in this discussion - the
old adage of busy life being my crutch. Thanks to the theads I did
make a starter to try and re-start this batch. I was successful and
this weekend I have started working on getting the batch clear and
ready for bottling. It's been a fun experiment though not quite the
taste I was hoping for (at least the test glass I couldn't resist
trying the other night), I'm sure this will improve with age.

While I haven't taken the time to write in, it's been great fun to
follow the threads here and it's done a lot to keep my interest piqued
for wine-making adventures.

Cheers and merry Christmas.

Chris
Charlottetown, PEI, Canada