There have been numerous interesting threads on storing opened wine and I
don't doubt more are coming :-). However, I don't recall anything about the
use of oxygen absorbers to help preservation. Does anyone know if oxygen
absorbers are used in the wine industry? You may have come across them with
packaged foods, usually as little packets containing iron oxide marked "do
not eat" with names like Oxy-eater. Oxygen absorbing beer bottle stoppers
can be bought, eg. www.wineandhop.com, but I have not seen them for wine.


--
James V. Silverton
Potomac, Maryland, USA

I have not seen anything about oxygen absorbers being used by the wine
industry. They usually use an inert gas such as nitrogen to flush out
air when they feel a need to do so. There are very effective oxygen
absorbing compounds sold for chemical research, but I have not heard of
these being used by the food industry other than for research purposes.
Some of these would not be safe around foods, and any that were might
require very expensive testing to gain FDA approval for food use. Wine
itself, especially red, can absorb oxygen, and any oxygen in the neck of
the bottle probably is consumed fairly rapidly. The main problem then is
to have a very effective seal so that very little more air can leak into
the bottle.Some oxygen exposure seems to benefit many reds. They often
are exposed to air when being made and aging in oak casks. This seems to
soften and smooth the wine, provided there is not too much contact with
air. Thus I doubt if the small amount of air sealed into a red will have
much effect on the quality of the wine in the long term. Leaky bottles
are another matter. Wine makers who worry about the oxygen in the air in
the neck of the bottle sometimes use nitrogen to flush out the air. An
oxygen absorber might be more useful for beer or fruit juices that do
not contain large amounts of oxygen-hungry compounds such as found in
red wines.

My mailbox is always full to avoid spam. To contact me,
erase from my email address. Then add . I
do not check this box every day, so post if you need a quick response.

"James Silverton" > wrote in message >...

> Does anyone know if oxygen absorbers are used in the wine industry?

May not be exactly what you're thinking of, but SO2 is used in wine to
prevent oxidation.

Andy

"JEP" > wrote in message
om...
> "James Silverton" > wrote in message
>...
>
> > Does anyone know if oxygen absorbers are used in the wine industry?
>
> May not be exactly what you're thinking of, but SO2 is used in wine to
> prevent oxidation.
>
> Andy

Thanks, but it was my impression that SO2 was used to kill off wild yeasts
and possibly other unwanted critters (g). I don't really know how it would
prevent oxidation unless you used it displace oxygen and I suspect that
would lead to unwanted acidification.


--
James V. Silverton
Potomac, Maryland, USA

James Silverton wrote:

>
> Thanks, but it was my impression that SO2 was used to kill off wild yeasts
> and possibly other unwanted critters (g). I don't really know how it would
> prevent oxidation unless you used it displace oxygen and I suspect that
> would lead to unwanted acidification.

Actually, SO2 (or metabisulfite as it's usually used) reacts readily with
oxygen to form sulfate (oxidation of sulfur IV to sulfur VI) and water. The
reaction is:

SO2 + H2O --> H2SO3 + 1/2O2 --> H2SO4

Mark Lipton

Yes, SO2 is one of the many compounds that will react with oxygen, and
it is used in fairly small quantites in making many wines. However, it
can be rather unpleasant in taste and smell if much is used. Also it may
cause health problems for a few people. I doubt if it would be approved
for use in food if it were just now being introduced. However use goes
back long before most countries had many laws concerning food additives.
The bright red "Maraschino" cherries sold in the US for food decoration
when I was young often reeked of SO2. Ascorbic acid also will combine
with oxygen. It often is added to fruit before freezing to prevent
browning. Ascorbic acid, aka Vitamin C, is needed by all of us and
tolerated in fairly large amounts. However it is not as good a
disinfectant as SO2.

My mailbox is always full to avoid spam. To contact me, erase
from my email address. Then add . I do not
check this box every day, so post if you need a quick response.

(Cwdjrx _) wrote:

> Yes, SO2 is one of the many compounds that will react with
> oxygen, and it is used in fairly small quantites in making many
> wines.

Not "many", but all, except for the minute amount of totally
sulphur free wines (which would be labelled as such, as this would
be their USP). The problem with the latter is their life-span,
that can be counted in weeks, seldom months, never years.

M.

On Mon, 01 Dec 2003 10:44:42 -0500, Mark Lipton >
wrote:
>
>James Silverton wrote:
>
>>
>> Thanks, but it was my impression that SO2 was used to kill off wild yeasts
>> and possibly other unwanted critters (g). I don't really know how it would
>> prevent oxidation unless you used it displace oxygen and I suspect that
>> would lead to unwanted acidification.
>
>Actually, SO2 (or metabisulfite as it's usually used) reacts readily with
>oxygen to form sulfate (oxidation of sulfur IV to sulfur VI) and water. The
>reaction is:
>
>SO2 + H2O --> H2SO3 + 1/2O2 --> H2SO4
>
>Mark Lipton

If I recall my high school chemistry correctly, the last compound in
the above equation is sulphuric acid, not something I would like to
consume in any quantity, no matter how small.

Vino

Vino wrote:

>
> >SO2 + H2O --> H2SO3 + 1/2O2 --> H2SO4
> >
> >Mark Lipton
>
> If I recall my high school chemistry correctly, the last compound in
> the above equation is sulphuric acid, not something I would like to
> consume in any quantity, no matter how small.

Keep in mind that I've shown the reaction in its acid form, but at the pH of
wine the reaction would be:

NaHSO3 + 1/2O2 --> NaHSO4

(bisulfite) (bisulfate)

The sodium bisulfate formed in this reaction is an FDA approved additive to
food. The major problem with sulfuric acid is just that it's so strongly
acidic that it damages tissue; bisulfate, being far less acidic, is harmless.

HTH
Mark Lipton

(Cwdjrx _) wrote in message >...
> Yes, SO2 is one of the many compounds that will react with oxygen, and
> it is used in fairly small quantites in making many wines. However, it
> can be rather unpleasant in taste and smell if much is used. Also it may
> cause health problems for a few people. I doubt if it would be approved
> for use in food if it were just now being introduced. However use goes
> back long before most countries had many laws concerning food additives.
> The bright red "Maraschino" cherries sold in the US for food decoration
> when I was young often reeked of SO2. Ascorbic acid also will combine
> with oxygen. It often is added to fruit before freezing to prevent
> browning. Ascorbic acid, aka Vitamin C, is needed by all of us and
> tolerated in fairly large amounts. However it is not as good a
> disinfectant as SO2.
>
Oh, I think SO2 would be easily approved. It is very useful in
preserving a wide range of foods including wine and safe for the vast
majority of us. Now, *alcohol* getting approval, that's a different
story ;^)

"James Silverton" > wrote in message >...
> "JEP" > wrote in message
> om...
> > "James Silverton" > wrote in message
> >...
> >
> > > Does anyone know if oxygen absorbers are used in the wine industry?
> >
> > May not be exactly what you're thinking of, but SO2 is used in wine to
> > prevent oxidation.
> >
> > Andy
>
> Thanks, but it was my impression that SO2 was used to kill off wild yeasts
> and possibly other unwanted critters (g). I don't really know how it would
> prevent oxidation unless you used it displace oxygen and I suspect that
> would lead to unwanted acidification.

Mark Lipton has already given the chemical equation involved but I
thought it should be noted that you are also correct. S02 has
multiple uses in winemaking. It is often used at crush for the reason
you mentioned, although I believe the operative word is "stun", not
"kill" since the wild yeasts aren't actually killed. The idea is to
suppress the wild yeast population in order clear the field for
introduction of a cultured yeast that has been selected in part for
its SO2-tolerance. Most "free" SO2 is consumed during primary
fermentation. Once malolactic fermentation (which cannot stand much
SO2) is complete, SO2 levels are bumped back up - and often again just
before bottling. The purpose then is partially to prevent unwanted
microbial activity in the bottle but the more important one is to
prevent oxidation. SO2 has the effect of scavenging oxygen from the
wine through the reaction Mark detailed; it is mostly by preventing
oxidation that SO2 makes wine ageable in terms of years rather than
months.

- Mark W.

"Vino" > wrote in message
...
> On Mon, 01 Dec 2003 10:44:42 -0500, Mark Lipton >
> wrote:
> >
> >James Silverton wrote:
> >
> >>
> >> Thanks, but it was my impression that SO2 was used to kill off wild
yeasts
> >> and possibly other unwanted critters (g). I don't really know how it
would
> >> prevent oxidation unless you used it displace oxygen and I suspect that
> >> would lead to unwanted acidification.
> >
> >Actually, SO2 (or metabisulfite as it's usually used) reacts readily with
> >oxygen to form sulfate (oxidation of sulfur IV to sulfur VI) and water.
The
> >reaction is:
> >
> >SO2 + H2O --> H2SO3 + 1/2O2 --> H2SO4
> >
> >Mark Lipton
>
> If I recall my high school chemistry correctly, the last compound in
> the above equation is sulphuric acid, not something I would like to
> consume in any quantity, no matter how small.
>
> Vino

That's exactly what it is, and you drink a little of it in every glass of
wine - including the wines made without added sulfites.

It's not dangerous in the concentrations present in table wines.

Look at it this way:
Your stomach contains hydrochloric acid, at pH ~3, which is present to break
down the food you eat into digestible liquids. You certainly wouldn't care
to drink pool acid, but it's really the same stuff that naturally occurs in
your stomach - just in lower concentration.

The same principle applies to sulfuric acid in wine.

Tom S

(Cwdjrx _) wrote in message >...
> Ascorbic acid also will combine
> with oxygen. It often is added to fruit before freezing to prevent
> browning. Ascorbic acid, aka Vitamin C, is needed by all of us and
> tolerated in fairly large amounts. However it is not as good a
> disinfectant as SO2.


Actually, ascorbic acid has been discounted as a long term
anti-oxidant for wine. I can't remember the details, but it actually
contributed to oxidation after a period of time. I could probably dig
up the details if anyone is interested.

I don't think many (if any) wine makers are currently using it.
Supposedly, it's ok to use ascorbic acid in combination with SO2, but
then why not just use SO2.

Andy

"JEP" > wrote in message
om...
> Actually, ascorbic acid has been discounted as a long term
> anti-oxidant for wine. I can't remember the details, but it actually
> contributed to oxidation after a period of time.

I have also read the same (but don't remember where).

> I don't think many (if any) wine makers are currently using it.

Ascorbic acid is still occasionally used in "problem" wines. If a wine
develops a disulfide problem due to incomplete or non-treatment of a
mercaptan/hydrogen sulfide problem, ascorbic acid is required to break the
disulfide bond so that copper can be used to treat the offending odor.
Obviously this is only done as a last resort, but the effect can be
dramatic.

Tom S

On Wed, 03 Dec 2003 07:12:18 GMT, "Tom S" >
wrote:

>
>> >
>> >SO2 + H2O --> H2SO3 + 1/2O2 --> H2SO4
>> >
>> >Mark Lipton
>>
>> If I recall my high school chemistry correctly, the last compound in
>> the above equation is sulphuric acid, not something I would like to
>> consume in any quantity, no matter how small.
>>
>> Vino
>
>That's exactly what it is, and you drink a little of it in every glass of
>wine - including the wines made without added sulfites.
>
>It's not dangerous in the concentrations present in table wines.
>
>Look at it this way:
>Your stomach contains hydrochloric acid, at pH ~3, which is present to break
>down the food you eat into digestible liquids. You certainly wouldn't care
>to drink pool acid, but it's really the same stuff that naturally occurs in
>your stomach - just in lower concentration.
>
>The same principle applies to sulfuric acid in wine.
>
>Tom S
>
I don't doubt the validity of what you say. Sometimes (maybe most of
the time; mabe ALL of the time) it's best to ignore what happens with
the stuff we put into our stomachs and simply enjoy the pleasures
associated with its getting there.

Vino

"Vino" > wrote in message
...
> Sometimes (maybe most of
> the time; mabe ALL of the time) it's best to ignore what happens with
> the stuff we put into our stomachs and simply enjoy the pleasures
> associated with its getting there.

I suspect there are exceptions.

Back in the early part of the 20th Century there was a patent elixir on the
market that supposedly had remarkable curative powers and gave its consumer
a warm feeling of well being - a sort of inner glow, as it were.

The product was called "Radithor" or some such. The active principle was
radium salts.
http://www.orau.org/ptp/collection/q...res/radith.htm

Tom S

"Tom S" > wrote in message .com>...
> Ascorbic acid is still occasionally used in "problem" wines. If a wine
> develops a disulfide problem due to incomplete or non-treatment of a
> mercaptan/hydrogen sulfide problem, ascorbic acid is required to break the
> disulfide bond so that copper can be used to treat the offending odor.
> Obviously this is only done as a last resort, but the effect can be
> dramatic.
>
> Tom S

Yes. Thanks. I forgot about about.

Of course, you still need to make sure the SO2 level is sufficient to
protect the wine from oxidation.

Andy