Hi folks,
I just wanted to get your input into the topic of topping up you barrels -
specifically how frequently you are topping them up.

I have several small barrels (around 50Litres) and have been in the habit of
topping them up weekly. My reading suggest that some people do this more or
less frequently or possibly not at all.... any comments?

steve

"steve small" > wrote in message
...
> Hi folks,
> I just wanted to get your input into the topic of topping up you barrels -
> specifically how frequently you are topping them up.
>
> I have several small barrels (around 50Litres) and have been in the habit
of
> topping them up weekly. My reading suggest that some people do this more
or
> less frequently or possibly not at all.... any comments?

For a barrel that small, weekly should be the minimum.

I top and taste my 228 liter barrels every two or three weeks. AFAIC, three
weeks is pushing it a bit. I've seen some barrels (_not_ mine!) around the
winery that have been so long between toppings that the heads are visibly
concave. I think that's pushing it _way_ too far.

Tom S

Tom,

For your 228L barrrel, what would you give as an estimate for the total
amount of "top-up wine" added over the course of barrel ageing? I'm curious
what a typical "concentration factor" is for wines, especially reds, aged in
barrels.

Thanks,
Aaron

"Tom S" > wrote in message
m...
>
> "steve small" > wrote in message
> ...
> > Hi folks,
> > I just wanted to get your input into the topic of topping up you
barrels -
> > specifically how frequently you are topping them up.
> >
> > I have several small barrels (around 50Litres) and have been in the
habit
> of
> > topping them up weekly. My reading suggest that some people do this more
> or
> > less frequently or possibly not at all.... any comments?
>
> For a barrel that small, weekly should be the minimum.
>
> I top and taste my 228 liter barrels every two or three weeks. AFAIC,
three
> weeks is pushing it a bit. I've seen some barrels (_not_ mine!) around
the
> winery that have been so long between toppings that the heads are visibly
> concave. I think that's pushing it _way_ too far.
>
> Tom S
>
>

steve small wrote:

> Hi folks,
> I just wanted to get your input into the topic of topping up you barrels -
> specifically how frequently you are topping them up.

I've a 228 litre and ~50 litre barrel... I am usually down in the cellar
weekly to check things, and top up if need be, though my cellar is
pretty cold, losses aren't as quick as they might be for some place that
is in a warmer climate.

--
charles

"Once ... in the wilds of Afghanistan, I lost my corkscrew, and we were
forced to live on nothing but food and water for days."
- W.C. Fields

"steve small" > wrote in message >...
> Hi folks,
> I just wanted to get your input into the topic of topping up you barrels -
> specifically how frequently you are topping them up.
>
> I have several small barrels (around 50Litres) and have been in the habit of
> topping them up weekly. My reading suggest that some people do this more or
> less frequently or possibly not at all.... any comments?
>
> steve

I would be on top of this especially with small barrels. It is amazing
how much "disappears" with all these fillings. I have several 5 &
10gal barrels where I blend and let age wine in. I top up every week
and you can in some 10g barrels see as much as 150 - 200ml be used.
This varies from barrel to barrel and how old they are. I usually
select the wine with which to use for this at the outset so that I
have some control of the finished product and this way I have "written
off" these top-of wines at the outset and don't feel the pain when you
see them disappear down the hole.

I would like to hear from others how they would deal with any vinegar
flies. I have one small barrel that seems to constantly be damp just
around the edge of the bunghole. The airlock shows constant pressure
and the wine taste fine. I check it daily, kill any vinegar flies if I
see any, wipe any moister up and have been spraying the area with
sulphur

I put in a pestomat and am switching the frequency weekly, but they
seem to still to appear just at this bunghole. I also keep a flytrap
right over it and I can see evidence of the small fly.

So if anyone of you have any suggestions I would be glad to hear them.

SG Brix

"Aaron Puhala" > wrote in message
...
> Tom,
>
> For your 228L barrrel, what would you give as an estimate for the total
> amount of "top-up wine" added over the course of barrel aging? I'm
curious
> what a typical "concentration factor" is for wines, especially reds, aged
in
> barrels.

I recently heard bandied about the number 7%. That was over the course of
about a year and a half, and it sounds reasonable to me. It's sort of hard
to estimate this accurately, since I always taste - sometimes with one or
more others "help", and occasionally pull a sample out for "evaluation"
purposes. :^)

Tom S

"sgbrix" > wrote in message
m...
> I would like to hear from others how they would deal with any vinegar
> flies. I have one small barrel that seems to constantly be damp just
> around the edge of the bunghole. The airlock shows constant pressure
> and the wine taste fine. I check it daily, kill any vinegar flies if I
> see any, wipe any moisture up and have been spraying the area with
> sulphur
>
> I put in a pestomat and am switching the frequency weekly, but they
> seem to still to appear just at this bunghole. I also keep a flytrap
> right over it and I can see evidence of the small fly.
>
> So if anyone of you have any suggestions I would be glad to hear them.

Why not wet a washcloth with sulfite solution, wring out most of the sulfite
and wrap it around the bung and the bottom of the airlock? I doubt that
they'd care to hang around that.

Tom S

"Tom S" > wrote in message . com>...
> "sgbrix" > wrote in message
> m...

> Why not wet a washcloth with sulfite solution, wring out most of the sulfite

Thanks Tom, but I have been wetting down a papertowel each time and
leaving it. Maybe I just should make a stronger solution. I just get
crazy whenever I see one of these critters.

SG Brix

"sgbrix" > wrote in message
om...
> "Tom S" > wrote in message
. com>...
> > "sgbrix" > wrote in message
> > m...
>
> > Why not wet a washcloth with sulfite solution, wring out most of the
sulfite
>
> Thanks Tom, but I have been wetting down a papertowel each time and
> leaving it. Maybe I just should make a stronger solution. I just get
> crazy whenever I see one of these critters.

I just sprinkle a little sulfite powder around the bung. The powder seems
to keep the flies away for a week or two. I wipe and blow the powder off
before pulling the bung.

"steve small" > wrote in message >...
> Hi folks,
> I just wanted to get your input into the topic of topping up you barrels -
> specifically how frequently you are topping them up.
>
> I have several small barrels (around 50Litres) and have been in the habit of
> topping them up weekly. My reading suggest that some people do this more or
> less frequently or possibly not at all.... any comments?
>
> steve

And another question. If you have to top up every week or so with 100
to 200 ml of wine, where does that top up wine come from? How do you
store variable volumes of wine for topping up? You can't take 100 ml
from a carbouy. Do you bottle wine prematurely? I suppose you could
top up with commercial wine and drink the remainder. What do you do?

Getting a barrel next year.

Dan

I have 50 L barrels as well (probably from the same place as Steve) and top
them up weekly (or every second week on occasion). Right now I have three
vintages in various stages in the "winery"; 2001 were bottled 3-4 months ago
and are not labeled, 2002 are in carboy for blending and 2003 are in barrel.
For topping up I use a similar wine from the 2001 bottles.

My barrel room is relatively warm (low to mid 60's) so weekly topping off is
important. As a reply to an earlier post, I have estimated that over the
course of a year I add back about 10L or 20% of the volume of a barrel.
Usually I have two wines go through a barrel, so this represents about a 10%
concentration for each wine.
Tim


"Dan Emerson" > wrote in message
om...
: "steve small" > wrote in message
>...
: > Hi folks,
: > I just wanted to get your input into the topic of topping up you
barrels -
: > specifically how frequently you are topping them up.
: >
: > I have several small barrels (around 50Litres) and have been in the
habit of
: > topping them up weekly. My reading suggest that some people do this more
or
: > less frequently or possibly not at all.... any comments?
: >
: > steve
:
: And another question. If you have to top up every week or so with 100
: to 200 ml of wine, where does that top up wine come from? How do you
: store variable volumes of wine for topping up? You can't take 100 ml
: from a carbouy. Do you bottle wine prematurely? I suppose you could
: top up with commercial wine and drink the remainder. What do you do?
:
: Getting a barrel next year.
:
: Dan

"Dan Emerson" > wrote in message
om...
> "steve small" > wrote in message
>...
> > Hi folks,
> > I just wanted to get your input into the topic of topping up you
barrels -
> > specifically how frequently you are topping them up.
> >
> > I have several small barrels (around 50Litres) and have been in the
habit of
> > topping them up weekly. My reading suggest that some people do this more
or
> > less frequently or possibly not at all.... any comments?
> >
> > steve
>
> And another question. If you have to top up every week or so with 100
> to 200 ml of wine, where does that top up wine come from? How do you
> store variable volumes of wine for topping up? You can't take 100 ml
> from a carbouy. Do you bottle wine prematurely? I suppose you could
> top up with commercial wine and drink the remainder. What do you do?
>
> Getting a barrel next year.
>
> Dan

Steve, Dan and All,

Barrels exchange roughly 2 ml of oxygen (O2) per liter of wine per year.
So, a 50 liter barrel exchanges 2 X 50 = 100 ml of O2 per year.
Or, 100 / 52 ~ 2 ml O2 per week.
Air contains about 20 ml of O2 per 100 ml.
So leaving 100 ml of head space in a small barrel just about doubles the
oxygen input.

100 ml is a pretty small head space, so I'm not sure that topping small
barrels once a week is necessarily a good thing. But, maybe may arithmetic
is wrong????

lum

Lum,

I haven't actually measured, but the top up of my headspace in my 60
liter barrels is more like a half bottle or even more every 2 weeks.
There is no leaking and the bung is on tightly.

Glen Duff
---------------


Lum wrote:

> "Dan Emerson" > wrote in message
> om...
>
>>"steve small" > wrote in message
>>
> >...
>
>>>Hi folks,
>>>I just wanted to get your input into the topic of topping up you
>>>
> barrels -
>
>>>specifically how frequently you are topping them up.
>>>
>>>I have several small barrels (around 50Litres) and have been in the
>>>
> habit of
>
>>>topping them up weekly. My reading suggest that some people do this more
>>>
> or
>
>>>less frequently or possibly not at all.... any comments?
>>>
>>>steve
>>>
>>And another question. If you have to top up every week or so with 100
>>to 200 ml of wine, where does that top up wine come from? How do you
>>store variable volumes of wine for topping up? You can't take 100 ml
>>from a carbouy. Do you bottle wine prematurely? I suppose you could
>>top up with commercial wine and drink the remainder. What do you do?
>>
>>Getting a barrel next year.
>>
>>Dan
>>
>
> Steve, Dan and All,
>
> Barrels exchange roughly 2 ml of oxygen (O2) per liter of wine per year.
> So, a 50 liter barrel exchanges 2 X 50 = 100 ml of O2 per year.
> Or, 100 / 52 ~ 2 ml O2 per week.
> Air contains about 20 ml of O2 per 100 ml.
> So leaving 100 ml of head space in a small barrel just about doubles the
> oxygen input.
>
> 100 ml is a pretty small head space, so I'm not sure that topping small
> barrels once a week is necessarily a good thing. But, maybe may arithmetic
> is wrong????
>
> lum
>
>
>
>

"Glen Duff" > wrote in message
...
> Lum,
>
> I haven't actually measured, but the top up of my headspace in my 60
> liter barrels is more like a half bottle or even more every 2 weeks.
> There is no leaking and the bung is on tightly.

Wow! That sounds like a _lot_ of evaporative loss to me. I probably lose
about the same volume over the same length of time from a barrel almost 4
times the size.

I'd guess that your losses are that high because the staves are thinner in
your barrel than they are in my 228 liter export barrels, which are an inch
thick. Either that, or you recently filled a new barrel and it's still
soaking up wine.

Tom S

"Dan Emerson" > wrote in message
om...
> And another question. If you have to top up every week or so with 100
> to 200 ml of wine, where does that top up wine come from? How do you
> store variable volumes of wine for topping up? You can't take 100 ml
> from a carbouy.

No, but you _can_ break down a carboy to gallon jugs, liter bottles and
smaller sizes. Also, when tasting and topping, pull out a sample such that
your topping wine volume is a bit smaller than the headspace, pour in the
topping wine, top off from the sample you just pulled and use the remainder
for tasting. No leftovers that way!

Tom S

Dan Emerson wrote:

>
> And another question. If you have to top up every week or so with 100
> to 200 ml of wine, where does that top up wine come from? How do you
> store variable volumes of wine for topping up? You can't take 100 ml
> from a carbouy. Do you bottle wine prematurely? I suppose you could
> top up with commercial wine and drink the remainder. What do you do?

I've found it effective to use 1 and 2 litre pop bottles... I'll top
off, and squeeze the bottle until there is no airspace left. This has
worked well for me.

--
charles

"Once ... in the wilds of Afghanistan, I lost my corkscrew, and we were
forced to live on nothing but food and water for days."
- W.C. Fields

"Tom S" > wrote in message
. com...
>
Either that, or you recently filled a new barrel and it's still
> soaking up wine.
>

How long can that process go on for? Can the amount that needs to be soaked
up be expressed as a percentage of barrel volume? I'm just wondering how
much I will lose to soak-in on my 30 liter barrel.

Brian

"Brian Lundeen" > wrote in message
...
>
> "Tom S" > wrote in message
> . com...
> >
> Either that, or you recently filled a new barrel and it's still
> > soaking up wine.
> >
>
> How long can that process go on for? Can the amount that needs to be
soaked
> up be expressed as a percentage of barrel volume? I'm just wondering how
> much I will lose to soak-in on my 30 liter barrel.

I don't really know, but IIRC Lum gave a figure like 4 gallons for a 60
gallon barrel.

You also should consider that depending on temperature variations in the
winery the amount of topping wine required may vary from zero to at least
twice "normal".

Tom S

Brian Lundeen wrote:

> "Tom S" > wrote in message
> . com...
>
> Either that, or you recently filled a new barrel and it's still
>
>>soaking up wine.
>>
>
>
> How long can that process go on for? Can the amount that needs to be soaked
> up be expressed as a percentage of barrel volume? I'm just wondering how
> much I will lose to soak-in on my 30 liter barrel.
>
> Brian
>
>

You really can't quote a percentage of volume. You might be able to get
a percentage of surface area of the barrel, which is quite different.
For an exercise I did some calculations assuming that a barrel was a
cylinder twice as high as wide.
For a cylinder 50cm in circumference and 100cm high I came up with a
surface to volume figure of 1:10
I then halved the measurements (1/8th the volume) and got a figure of 1:5
Altering ratios made quite a difference as well so unless you do the
geometry better than I did you can't calculate it just like this.

Tom,

Just checked my barrels and the 60 liter barrel containing Chardonnay
sur lie needed just about exactly a half bottle and according to my
records it was last filled about 2 weeks ago. The barrel is a Hungarian
(European Oak) burgundy squat styled and is about 1 1/2 years old. I
measured the staves and they are either 7/8" or a full 1".

I too am surprised at the loss although I expect smaller barrels will
lose proportionately more just on the basis of a higher surface/volume
ratio.

I am going to start recording the date and volume of top-up of both my
white and red barrels.

Cheers,

Glen Duff
--------------

Tom S wrote:

> "Glen Duff" > wrote in message
> ...
>
>>Lum,
>>
>>I haven't actually measured, but the top up of my headspace in my 60
>>liter barrels is more like a half bottle or even more every 2 weeks.
>>There is no leaking and the bung is on tightly.
>>
>
> Wow! That sounds like a _lot_ of evaporative loss to me. I probably lose
> about the same volume over the same length of time from a barrel almost 4
> times the size.
>
> I'd guess that your losses are that high because the staves are thinner in
> your barrel than they are in my 228 liter export barrels, which are an inch
> thick. Either that, or you recently filled a new barrel and it's still
> soaking up wine.
>
> Tom S
>
>
>

RE>
> And another question. If you have to top up every week or so with 100
> to 200 ml of wine, where does that top up wine come from? How do you
> store variable volumes of wine for topping up? You can't take 100 ml
> from a carbouy. Do you bottle wine prematurely? I suppose you could
> top up with commercial wine and drink the remainder. What do you do?
>
I generally make more wine than my barrels will hold, and use the leftover
for topping up. I have a collection of smaller jugs and bottles from
1gallon - 125ml and break the larger amounts into smaller bottles to top up
from.

I usually top up about 80-125ml per week to the barrels, but my basement is
relatively cool and fairly humid.

I am curious about Lums comments regarding O2 exchange, because it is
precisely oxidation that concerns me - specifically with the frequency of
opening the barrels to top them up. I have read that some wineries do not
top up at all - they bung and roll the barrel to keep the bung hole wet and
then leave them for months. Strikes me as an odd approach but there you are.

steve

"Tom S" > wrote in message
. com...

"Glen Duff" > wrote in message
...
> Lum,
>
> I haven't actually measured, but the top up of my headspace in my 60
> liter barrels is more like a half bottle or even more every 2 weeks.
> There is no leaking and the bung is on tightly.

: Wow! That sounds like a _lot_ of evaporative loss to me. I probably lose
: about the same volume over the same length of time from a barrel almost 4
: times the size.
:
: I'd guess that your losses are that high because the staves are thinner in
: your barrel than they are in my 228 liter export barrels, which are an
inch
: thick. Either that, or you recently filled a new barrel and it's still
: soaking up wine.
:
: Tom S

My experience has been similar to Glens. I have two American Oak barrels, 1
Hungarian and this year added a French barrel (Moreau). The grain on the
French is by far the tightest looking of the barrels and although it is the
newest (the others are at least 4 years old) my impression is that it shows
the least amount of evaporative loss. I will have to start taking careful
notes of the added volumes to see if this is the case.
Tim

"steve small" > wrote in message
...
> I am curious about Lums comments regarding O2 exchange, because it is
> precisely oxidation that concerns me - specifically with the frequency of
> opening the barrels to top them up.

I suspect that actually opening the barrel for topping contributes much less
significantly than the diffusion of oxygen through the staves. After all,
how long is the surface of the wine exposed during topping, and how big is
that surface? OTOH, the surface of the wine within the aggregate of all the
staves and heads is very much larger, and is exposed to air for the entire
time the wine is in the barrel. Also, since the wine penetrates to varying
depths within the staves the surface area exposed to diffusion through the
staves will be textured, and therefore have a much greater effective surface
area than the inside surface of the barrel.

> I have read that some wineries do not
> top up at all - they bung and roll the barrel to keep the bung hole wet
and
> then leave them for months.

That used to be more common when redwood bungs were still in use and before
the advent of steel tubing barrel racks, but there are probably still
wineries that do it that way with silicone bungs. I haven't seen rolled
barrels in quite awhile, and AFAIC that's not a desirable approach. I need
to keep closer tabs on the progress of my wines.

Incidentally, I remember that the Parducci winery used to bung barrels tight
and stand them on _end_ on stacked pallets! That would make me _very_
nervous.

Tom S

"Tom S" > wrote in message
. com...
>
> "steve small" > wrote in message
> ...
> > I am curious about Lums comments regarding O2 exchange, because it is
> > precisely oxidation that concerns me - specifically with the frequency
of
> > opening the barrels to top them up.
>
> I suspect that actually opening the barrel for topping contributes much
less
> significantly than the diffusion of oxygen through the staves. After all,
> how long is the surface of the wine exposed during topping, and how big is
> that surface? OTOH, the surface of the wine within the aggregate of all
the
> staves and heads is very much larger, and is exposed to air for the entire
> time the wine is in the barrel. Also, since the wine penetrates to
varying
> depths within the staves the surface area exposed to diffusion through the
> staves will be textured, and therefore have a much greater effective
surface
> area than the inside surface of the barrel.
>
> > I have read that some wineries do not
> > top up at all - they bung and roll the barrel to keep the bung hole wet
> and
> > then leave them for months.
>
> That used to be more common when redwood bungs were still in use and
before
> the advent of steel tubing barrel racks, but there are probably still
> wineries that do it that way with silicone bungs. I haven't seen rolled
> barrels in quite awhile, and AFAIC that's not a desirable approach. I
need
> to keep closer tabs on the progress of my wines.
>
> Incidentally, I remember that the Parducci winery used to bung barrels
tight
> and stand them on _end_ on stacked pallets! That would make me _very_
> nervous.
>
> Tom S

Please let me try my arithmetic again.

A new, 225 liter barrel exchanges, through the staves and heads, about 2 ml
of oxygen (O2) per liter of wine per year .

Therefore, a 225 liter barrel exchanges 2 X 225 = 450 ml of O2 per year.
So, 450 / 52 = 8.6 ml of oxygen per week goes into the barrel through the
staves.

Air contains about 20% oxygen.

If a 225 liter barrel is topped up once each week, and if 10 ml of head
space remains in the barrel when the bung is replaced after topping up, then
2 ml of oxygen is introduced into the barrel (any O2 in the barrel when the
bung is replaced will end up in the wine). 10 ml of head space introduces
about 20% ( 2 / 10.6) of the weekly oxygen input.

But, 10 ml of head space after topping is a small amount. If 100 ml of
head space remains when the bung is replaced, then 20 ml of O2 is introduced
into the barrel. In this case, weekly topping up introduces about 2.5 times
more O2 than that coming in through the staves.

What am I missing here???

"Lum" > wrote in message
...
> Please let me try my arithmetic again.
>
> A new, 225 liter barrel exchanges, through the staves and heads, about 2
ml
> of oxygen (O2) per liter of wine per year .
>
> Therefore, a 225 liter barrel exchanges 2 X 225 = 450 ml of O2 per year.
> So, 450 / 52 = 8.6 ml of oxygen per week goes into the barrel through
the
> staves.
>
> Air contains about 20% oxygen.
>
> If a 225 liter barrel is topped up once each week, and if 10 ml of head
> space remains in the barrel when the bung is replaced after topping up,
then
> 2 ml of oxygen is introduced into the barrel (any O2 in the barrel when
the
> bung is replaced will end up in the wine). 10 ml of head space introduces
> about 20% ( 2 / 10.6) of the weekly oxygen input.
>
> But, 10 ml of head space after topping is a small amount. If 100 ml of
> head space remains when the bung is replaced, then 20 ml of O2 is
introduced
> into the barrel. In this case, weekly topping up introduces about 2.5
times
> more O2 than that coming in through the staves.
>
> What am I missing here???

Only one little thing that I can think of. I don't know about you, but when
I top and bung a barrel I leave _zero_ headspace - not 100 ml. Not even 10
ml. Zero.

I don't use cupped bungs because I don't want any air trapped when I bung a
barrel. Frankly, I don't understand why Boswell even makes them.

Tom S

>
> Only one little thing that I can think of. I don't know about you, but when
> I top and bung a barrel I leave _zero_ headspace - not 100 ml. Not even 10
> ml. Zero.
>
> I don't use cupped bungs because I don't want any air trapped when I bung a
> barrel. Frankly, I don't understand why Boswell even makes them.
>
> Tom S


Ullage (topping-up) causes the oxygen exposure in oak barrels.
Oxygen does not enter through the staves or head of a sound securely
bunged barrel. Water and alcohol will permeate outward creating a
vacuum in the barrel. Examination of the stave cross-section reveals
the "wine side" to be "wine logged" or saturated to a average depth of
2- 6 mm. Progressing outward the moisture content abruptly diminishes
to 18% at the centre of the stave and 8% to 12% at the outer surface
relative to the cellar humidity. The point being, that were oxygen to
gain access to the wine via the staves or head, the inner 6 mm would
show evidence of oxidation. Such evidence in sound securely bunged
barrels does not exist as Singleton, Vernon L., elaborates "Vinifera
Wine Growers Journal", Vol. 8, No. 4,(1981:231).
Whether the barrel is loose-bunged or tight-bunged and the cellar
temperature and humidity influence the evaporative losses and volume
of ullage. A barrel is said to be loose bunged when the bung is
topmost and above the wine level. Tight bunged when the (silicone)
bung is fitted and the barrel rotated such that the bung is beneath
the wine surface, which in my opinion offers the best seal against
oxygen infiltration via the vacuum effect and the bung position.
Oxygen does not enter through the staves or head of a sound securely
bunged barrel. Water and alcohol will permeate outward creating a
vacuum which is apparent when you pull a secure bung. Wine in topped
up barrels is exposed to oxygen during racking and topping made
necessary by evaporative ullage (Angel's Share).
Zinman

"zinman" > wrote in message
om...
> >
> > Only one little thing that I can think of. I don't know about you, but
when
> > I top and bung a barrel I leave _zero_ headspace - not 100 ml. Not even
10
> > ml. Zero.
> >
> > I don't use cupped bungs because I don't want any air trapped when I
bung a
> > barrel. Frankly, I don't understand why Boswell even makes them.
> >
> > Tom S
>
>
> Ullage (topping-up) causes the oxygen exposure in oak barrels.
> Oxygen does not enter through the staves or head of a sound securely
> bunged barrel. Water and alcohol will permeate outward creating a
> vacuum in the barrel. Examination of the stave cross-section reveals
> the "wine side" to be "wine logged" or saturated to a average depth of
> 2- 6 mm. Progressing outward the moisture content abruptly diminishes
> to 18% at the centre of the stave and 8% to 12% at the outer surface
> relative to the cellar humidity. The point being, that were oxygen to
> gain access to the wine via the staves or head, the inner 6 mm would
> show evidence of oxidation. Such evidence in sound securely bunged
> barrels does not exist as Singleton, Vernon L., elaborates "Vinifera
> Wine Growers Journal", Vol. 8, No. 4,(1981:231).
> Whether the barrel is loose-bunged or tight-bunged and the cellar
> temperature and humidity influence the evaporative losses and volume
> of ullage. A barrel is said to be loose bunged when the bung is
> topmost and above the wine level. Tight bunged when the (silicone)
> bung is fitted and the barrel rotated such that the bung is beneath
> the wine surface, which in my opinion offers the best seal against
> oxygen infiltration via the vacuum effect and the bung position.
> Oxygen does not enter through the staves or head of a sound securely
> bunged barrel. Water and alcohol will permeate outward creating a
> vacuum which is apparent when you pull a secure bung. Wine in topped
> up barrels is exposed to oxygen during racking and topping made
> necessary by evaporative ullage (Angel's Share).
> Zinman

Zinman,
Until a few month ago, I agreed with your assessment of oxygen transport
through barrels, but I don't agree now. Please take a look at the info here
http://www.flextank.com.au/PDF_Files...rrels-Work.pdf
and at the material presented in reference #3 of the above paper.
Apparently barrel dynamics were never measured until recently.
lum

"zinman" > wrote in message
om...
> Ullage (topping-up) causes the oxygen exposure in oak barrels.
> Oxygen does not enter through the staves or head of a sound securely
> bunged barrel. Water and alcohol will permeate outward creating a
> vacuum in the barrel. Examination of the stave cross-section reveals
> the "wine side" to be "wine logged" or saturated to a average depth of
> 2- 6 mm. Progressing outward the moisture content abruptly diminishes
> to 18% at the centre of the stave and 8% to 12% at the outer surface
> relative to the cellar humidity. The point being, that were oxygen to
> gain access to the wine via the staves or head, the inner 6 mm would
> show evidence of oxidation. Such evidence in sound securely bunged
> barrels does not exist as Singleton, Vernon L., elaborates "Vinifera
> Wine Growers Journal", Vol. 8, No. 4,(1981:231).

That's a prestigious reference (if a little out of date).
IOW, I'm not convinced.

> Whether the barrel is loose-bunged or tight-bunged and the cellar
> temperature and humidity influence the evaporative losses and volume
> of ullage.

Temperature obviously increases evaporative losses. The effect of humidity
is to shift the ratio of alcohol evaporation vs water evaporation. In a
humid cellar, alcohol evaporates in a higher proportion than does water.
The opposite occurs in a dry cellar.

A barrel is said to be loose bunged when the bung is
> topmost and above the wine level. Tight bunged when the (silicone)
> bung is fitted and the barrel rotated such that the bung is beneath
> the wine surface

Au contraire. Tight bunged means exactly what it says: the bung is jammed
hard into the bunghole such that it forms an airtight seal. It has nothing
to do with rotation of the barrel or where the surface of the wine is with
respect to the bung. A barrel with the bung vertical can definitely be
hermetically sealed in this fashion.

Loose bunging is when the bung is merely set in place, allowing the barrel
to vent pressure (typically). This is often done when ML is not yet
complete. Some winemakers use one-way "venting" silicone bungs or airlocks
for this purpose, but many do not. I've even seen baggies filled with
bentonite laid across the bunghole to effect "loose bunging".

Wine in topped
> up barrels is exposed to oxygen during racking and topping made
> necessary by evaporative ullage (Angel's Share).

True, but that effect is considered minor in comparison to the slow
diffusion of oxygen through the staves. Only glass or metal are capable of
totally barring the diffusion of most gases. Plastics are not, although
some plastics are better than others. Porous, organic materials like wood
are much more permeable than most plastics.

Tom S