Can I simply bubble CO2 through my wine rather than racking and aerating
it to scrub out H2S? It seems many winemakers use aeration, but that
might be because they lack corny tanks used by brewers. Is that
assumption correct, or is there something I'm missing?

Warren Place

"Warren Place" > wrote in message
...
> Can I simply bubble CO2 through my wine rather than racking and aerating
> it to scrub out H2S?

That will probably work just as well as aeration, without the additional
risk of oxidizing to mercaptan.

If the CO2 doesn't do the trick, there's always copper.

Tom S

On Mon, 10 Nov 2003, Tom S wrote:
> "Warren Place" > wrote in message
> ...
> > Can I simply bubble CO2 through my wine rather than racking and aerating
> > it to scrub out H2S?
>
> That will probably work just as well as aeration, without the additional
> risk of oxidizing to mercaptan.
>
> If the CO2 doesn't do the trick, there's always copper.
>
> Tom S
Actually, I was thinking of copper also. I planned to toss a
copper wool pad into the carboy (sanitized with boiling water), and pin it
down with my racking cane. I hoped that this would help reduce the amount
of H2S, but in case it doesn't do enough, I'll follow with bubbling CO2
through the wine. With bubbling CO2, would small bubble be more effective
than larger bubbles?
Warren Place

"Warren Place" > wrote in message
...
> Actually, I was thinking of copper also. I planned to toss a
> copper wool pad into the carboy (sanitized with boiling water), and pin it
> down with my racking cane. I hoped that this would help reduce the amount
> of H2S, but in case it doesn't do enough, I'll follow with bubbling CO2
> through the wine. With bubbling CO2, would small bubble be more effective
> than larger bubbles?

Yes, but I'd start with CO2 first, and if that doesn't clear the problem
treat it with copper. I wouldn't recommend using a copper wool pad though.
Copper acts pretty quickly on H2S. By the time you realize the problem's
been fixed, the copper pad will have been in there too long, and how do you
plan to fish it out? Too much copper is not a good thing in the wine. A
section of clean ½" copper pipe would be easier to use and control the
contact time of. Just stir until the stink goes away.

Tom S

On Mon, 10 Nov 2003, Tom S wrote:
> I wouldn't recommend using a copper wool pad though.
> Copper acts pretty quickly on H2S. By the time you realize the problem's
> been fixed, the copper pad will have been in there too long, and how do you
> plan to fish it out?
> Tom S
I was thinking of stuffing the pad into the carboy containing the
wine, placing the racking cane tip into the wool, and racking the wine
through the pad as it is transerred to a new carboy. I'll remove the pad
when I clean out the empty carboy by grabbing it with a coat hanger. It
sounds like there would be less oxidation occuring with the wool pad
method than stirring with pipe, but less control over copper contact time
(might be too much copper by the time I'm done racking).
Warren Place

On Mon, 10 Nov 2003, Tom S wrote:
> "Warren Place" > wrote in message
> ...
> > Actually, I was thinking of copper also. I planned to toss a
> > copper wool pad into the carboy (sanitized with boiling water), and pin=
it
> > down with my racking cane. I hoped that this would help reduce the amo=
unt
> > of H2S, but in case it doesn't do enough, I'll follow with bubbling CO2
> > through the wine. With bubbling CO2, would small bubble be more effect=
ive
> > than larger bubbles?
>
> Yes, but I'd start with CO2 first, and if that doesn't clear the problem
> treat it with copper. I wouldn't recommend using a copper wool pad thoug=
h.
> Copper acts pretty quickly on H2S. By the time you realize the problem's
> been fixed, the copper pad will have been in there too long, and how do y=
ou
> plan to fish it out? Too much copper is not a good thing in the wine. A
> section of clean =BD" copper pipe would be easier to use and control the
> contact time of. Just stir until the stink goes away.
>
> Tom S
=09Well, I tried scrubbing my wine with CO2. It'll take a lot of CO2
to do what a little CuSO4 can do. I'll add some copper and see if that
fixes it. A professor at UC Davis pointed out that a potential problem
with adding CO2 is that I might also scrub out desired aromas.
Warren Place

"Warren Place" > wrote in message
...
> Well, I tried scrubbing my wine with CO2. It'll take a lot of CO2
to do what a little CuSO4 can do. I'll add some copper and see if that
fixes it. A professor at UC Davis pointed out that a potential problem
with adding CO2 is that I might also scrub out desired aromas.

Quite true. CO2 bubbling might help with a wine that has a _slight_ H2S
problem though. Copper fining is a more drastic step, which might be
required for a more severe case.

Tom S

Just another little fact about sparging: an inert gas is used to
avoid its becoming dissolved in the solution to be degassed. CO2 will
dissolve in your wine and not only be useless at removing the H2S but
then will interfere in the clarification.

You got some expert advice earlier with this problem. I suggest you go
with Tom's wisdom about the minimal treatment of stirring with a
copper pipe.

THE STIRRING WILL REMOVE GAS FASTER THAN SPARGING. THE COPPER WILL
PUSH THE H2S OUT FAST ENOUGH WITHOUT ADDING TOO MUCH COPPER TO THE
WINE.

Irene (who uses high tech when it is called for)

Warren Place > wrote in message >...
> On Mon, 10 Nov 2003, Tom S wrote:
> > "Warren Place" > wrote in message
> > ...
> > > Can I simply bubble CO2 through my wine rather than racking and aerating
> > > it to scrub out H2S?
> >
> > That will probably work just as well as aeration, without the additional
> > risk of oxidizing to mercaptan.
> >
> > If the CO2 doesn't do the trick, there's always copper.
> >
> > Tom S
> Actually, I was thinking of copper also. I planned to toss a
> copper wool pad into the carboy (sanitized with boiling water), and pin it
> down with my racking cane. I hoped that this would help reduce the amount
> of H2S, but in case it doesn't do enough, I'll follow with bubbling CO2
> through the wine. With bubbling CO2, would small bubble be more effective
> than larger bubbles?
> Warren Place

On 10 Nov 2003, Irene wrote:

> Just another little fact about sparging: an inert gas is used to
> avoid its becoming dissolved in the solution to be degassed. CO2 will
> dissolve in your wine and not only be useless at removing the H2S but
> then will interfere in the clarification.
Tom didn't say CO2 was useless. As far as CO2 dissolving, I'm not
worried about that. It will help prevent oxidation and I have all the
time in the world to wait for my wine to degass and clear.

> You got some expert advice earlier with this problem. I suggest you go
> with Tom's wisdom about the minimal treatment of stirring with a
> copper pipe.
>
> THE STIRRING WILL REMOVE GAS FASTER THAN SPARGING. THE COPPER WILL
> PUSH THE H2S OUT FAST ENOUGH WITHOUT ADDING TOO MUCH COPPER TO THE
> WINE.
I like the copper pipe idea and will try that since it is less
trouble. Thanks for corraborating Tom's advice.
Warren Place

"Warren Place" > wrote in message
...
>
> I like the copper pipe idea and will try that since it is less
> trouble. Thanks for corraborating Tom's advice.
> Warren Place
>
You can also get a small bottle of copper sulfate from www.piwine.com . If
you follow the directions you can add just enough copper to take care of the
problem AND you'll know exactly how much copper is in the wine. I used to
use the copper pipe/flashing/silverware approach, but once I discovered how
easy copper sulfate is and how little you need to solve the problem I
wouldn't do anything else anymore. It really works like magic.

Good Luck,

John

On 11/10/03 7:13 AM, in article
, "Irene"
> wrote:

> Just another little fact about sparging: an inert gas is used to
> avoid its becoming dissolved in the solution to be degassed. CO2 will
> dissolve in your wine and not only be useless at removing the H2S but
> then will interfere in the clarification.

On the contrary, the more CO2 gas is dissolved, the less the solution will
be able to hold onto the H2S gas. It will help to push the H2S out of
solution. And I don't understand your statement about CO2 interfering with
clarification. Why would that be?

--
Greg Cook
http://homepage.mac.com/gregcook/Wine

(remove spamblocker from my email)

Hm. My chemistry lessons kicked in and said:

--Inert gas (N2, Ar, He) is ~1000X less soluble than CO2. We use He
for those special applications, or a vacuum degasser (that would
probably be better for wine).

--CO2 reacts as well as dissolves easily. H2O + CO2 = H2CO3 = (H+)
and (HCO3-)

So my concern would be to avoid H2S + CO2 = ??? HCO2S- is pretty
disgusting.

About clarification: the smallest particulates are carried up and down
the bulk of the wine by the release and dissolution of the CO2. To
have the most effective compact sediment that is easily racked, one
stirs out the CO2. If you have bubbled in the CO2, it takes more
effort to get it back out again.

Note that this is significantly different than adding the headspace
dose of CO2 in industrial size tanks--that only displaces the air as
CO2 is heavier.

In general, I believe that one should use the most controllable form
of chemical addition that is available. YES to a fixed amount of
copper sulfate solution. NO to peroxide as its strength varies with
storage and it has stabilizers added...Likewise, the copper wire has
much more surface area than the pipe and therefore the reaction is
less controllable.

Irene

P.S. In case anybody is interested, there is the Journal of Food and
Agricultural Chemistry published by the American Chemical Society that
has a good number of papers concerning subjects such as the extraction
of colour from grapes, the detection of pesticides and ag-chemicals in
wine, the effect of grape species on volatiles...and many other topics
to do with viticulture, grapes and winemaking.


Greg Cook > wrote in message >.. .
> On 11/10/03 7:13 AM, in article
>

>> On the contrary, the more CO2 gas is dissolved, the less the
solution will
> be able to hold onto the H2S gas. It will help to push the H2S out of
> solution. And I don't understand your statement about CO2 interfering with
> clarification. Why would that be?