More SO2 Questions
 

At what points should you test for SO2? Also, I've read about the
relationship between pH and SO2, which leads to my next question- If you
test and determine that both SO2 and TA need adjusting, is there any
standard way of adjusting them? The way I understand it, free SO2 will go
up as pH goes down. Should you adjust the pH and re-test (this seems to be
the way as I see it)?
I suspect the answers to these questions vary widely as to whether you use
kits or fruits, etc. I'm currently on my second kit but would like to
eventually like to stretch out to fruit wines.
Thanks in advance. This is the most on-topic no nonsense newsgroup I've had
the pleasure to read.
Gerald
Todd

I always balance the acid as needed and then touch up SO2 if necessary.
I use pH and TA as a guide, some use only pH.

I'm not sure I follow you on the free SO2 rising as pH drops. I'm not
saying it is wrong, just that I'm not aware of it.

The amount of free SO2 generally accepted as protecting the wine rises
with a rise in pH. I use a chart, but the general rule of thumb is if
the pH is in the 3's just subtract 3 and multiply by 100; in other
words, if the pH is 3.5 you need about 50 ppm free, 3.2, 20 ppm.

As a general guide when making wine in 5 gallon batches in glass
carboys I usually start out at 100 PPM on reds. I don't add it to
whites until post ferment (unless it was added by the vendor).

Post ferment I would add 1/4 teaspoon to an unsulfited white, 1/8
tespoon to a red, (unless it had a rotten egg smell and I racked with a
lot of splashing, that would get 1/4 teaspoon) I use potassium
metabisulfite, I don't use sodium meta bisulfite in wine. I rack with
little splashing, so each rack gets 1/8 teaspoon. That equates to
around 20 ppm free.

I keep my wines at a pH less than 3.8 at all times and keep them
topped, I fiddle around very little. If it's over 3.6 I might measure
and bring the sulfite up to 50 or 60 ppm.

I normally only measure pre bottling and touch up if necessary.

Fruit wines are often more challanging when it comes to fiddling with
acid and pH, when you start doing those just remember to add things in
smaller increments, only add half of what you calculate you need, if
that. You can always add a little more after remeasuring.

Most kit wines are usually pretty well balanced and usually won't
require adjustments, but by measuring you will find out what values
usually appeal to you. That's one of the great things about making
your own, it's just like cooking. You can make what you like.

HTH.

Joe



Gerald Todd wrote:
> At what points should you test for SO2? Also, I've read about the
> relationship between pH and SO2, which leads to my next question- If
you
> test and determine that both SO2 and TA need adjusting, is there any
> standard way of adjusting them? The way I understand it, free SO2
will go
> up as pH goes down. Should you adjust the pH and re-test (this
seems to be
> the way as I see it)?
> I suspect the answers to these questions vary widely as to whether
you use
> kits or fruits, etc. I'm currently on my second kit but would like
to
> eventually like to stretch out to fruit wines.
> Thanks in advance. This is the most on-topic no nonsense newsgroup
I've had
> the pleasure to read.
>
Gerald
> Todd

Thanks.

"Joe Sallustio" > wrote in message
oups.com...
>I always balance the acid as needed and then touch up SO2 if necessary.
> I use pH and TA as a guide, some use only pH.
>
> I'm not sure I follow you on the free SO2 rising as pH drops. I'm not
> saying it is wrong, just that I'm not aware of it.
>
> The amount of free SO2 generally accepted as protecting the wine rises
> with a rise in pH. I use a chart, but the general rule of thumb is if
> the pH is in the 3's just subtract 3 and multiply by 100; in other
> words, if the pH is 3.5 you need about 50 ppm free, 3.2, 20 ppm.
>
> As a general guide when making wine in 5 gallon batches in glass
> carboys I usually start out at 100 PPM on reds. I don't add it to
> whites until post ferment (unless it was added by the vendor).
>
> Post ferment I would add 1/4 teaspoon to an unsulfited white, 1/8
> tespoon to a red, (unless it had a rotten egg smell and I racked with a
> lot of splashing, that would get 1/4 teaspoon) I use potassium
> metabisulfite, I don't use sodium meta bisulfite in wine. I rack with
> little splashing, so each rack gets 1/8 teaspoon. That equates to
> around 20 ppm free.
>
> I keep my wines at a pH less than 3.8 at all times and keep them
> topped, I fiddle around very little. If it's over 3.6 I might measure
> and bring the sulfite up to 50 or 60 ppm.
>
> I normally only measure pre bottling and touch up if necessary.
>
> Fruit wines are often more challanging when it comes to fiddling with
> acid and pH, when you start doing those just remember to add things in
> smaller increments, only add half of what you calculate you need, if
> that. You can always add a little more after remeasuring.
>
> Most kit wines are usually pretty well balanced and usually won't
> require adjustments, but by measuring you will find out what values
> usually appeal to you. That's one of the great things about making
> your own, it's just like cooking. You can make what you like.
>
> HTH.
>
> Joe
>
>
>
> Gerald Todd wrote:
>> At what points should you test for SO2? Also, I've read about the
>> relationship between pH and SO2, which leads to my next question- If
> you
>> test and determine that both SO2 and TA need adjusting, is there any
>> standard way of adjusting them? The way I understand it, free SO2
> will go
>> up as pH goes down. Should you adjust the pH and re-test (this
> seems to be
>> the way as I see it)?
>> I suspect the answers to these questions vary widely as to whether
> you use
>> kits or fruits, etc. I'm currently on my second kit but would like
> to
>> eventually like to stretch out to fruit wines.
>> Thanks in advance. This is the most on-topic no nonsense newsgroup
> I've had
>> the pleasure to read.
>>
> Gerald
>> Todd
>

Todd,

> At what points should you test for SO2?

Throughout the winemaking process.

> Also, I've read about the
> relationship between pH and SO2, which leads to my next question- If
you
> test and determine that both SO2 and TA need adjusting, is there any
> standard way of adjusting them?

You should firstly adjust TA, and then adjust SO2 depending on the pH.

> The way I understand it, free SO2 will go up as pH goes down.

The lower the pH, the more molecular SO2 will dissociate. This is the
primary form which protects the wine.

> Should you adjust the pH and re-test (this seems to be the way as I
see it)?

Adjust SO2 depending on whatever the pH happens to be.

> I suspect the answers to these questions vary widely as to whether
you use
> kits or fruits, etc.

The above is relevant for all wine - whether from fruit or kits.

You may find the following article helpful:
http://members.tripod.com/~BRotter/SO2.htm

Ben

"Gerald Todd" > wrote in message
news:1108751775.78920acfb063b537ea4751dda3f090f1@t eranews...
> At what points should you test for SO2?

Right after fermentation and just before bottling. If you're barrel aging,
you need to check it every few months too.

Also, I've read about the
> relationship between pH and SO2, which leads to my next question- If you
> test and determine that both SO2 and TA need adjusting, is there any
> standard way of adjusting them?

TA first; then check the pH and adjust the free SO2 according to that.

The way I understand it, free SO2 will go
> up as pH goes down.

Not true. Free SO2 is independent of pH within the normal range for wines.
You're thinking of _molecular_ free SO2, which IS pH dependent.

The three forms are (1) total SO2; (2) free SO2; (3) molecular free SO2.

Total SO2 is just what it sounds like: all SO2 in the wine. Much of that
total is bound to other things in the wine in such a way that it is not
available to protect the wine.

Free SO2 is available to dissociate into molecular free SO2, but that is a
pH dependent phenomenon. The lower the pH, the more this dissociation
occurs. The amount of molecular free SO2 needed to protect a wine from
spoilage and oxidation is roughly 0.8 ppm. At pH 3.2 it takes about 20 ppm
free SO2 to produce 0.8 ppm molecular SO2. At pH 3.6 it takes about 60 ppm
free SO2 to produce that same 0.8 ppm molecular SO2.

Tom S

Thank for the info. Just what I was looking for.

Gerald Todd
"Tom S" > wrote in message
...
>
> "Gerald Todd" > wrote in message
> news:1108751775.78920acfb063b537ea4751dda3f090f1@t eranews...
>> At what points should you test for SO2?
>
> Right after fermentation and just before bottling. If you're barrel
> aging, you need to check it every few months too.
>
> Also, I've read about the
>> relationship between pH and SO2, which leads to my next question- If you
>> test and determine that both SO2 and TA need adjusting, is there any
>> standard way of adjusting them?
>
> TA first; then check the pH and adjust the free SO2 according to that.
>
> The way I understand it, free SO2 will go
>> up as pH goes down.
>
> Not true. Free SO2 is independent of pH within the normal range for
> wines. You're thinking of _molecular_ free SO2, which IS pH dependent.
>
> The three forms are (1) total SO2; (2) free SO2; (3) molecular free SO2.
>
> Total SO2 is just what it sounds like: all SO2 in the wine. Much of that
> total is bound to other things in the wine in such a way that it is not
> available to protect the wine.
>
> Free SO2 is available to dissociate into molecular free SO2, but that is a
> pH dependent phenomenon. The lower the pH, the more this dissociation
> occurs. The amount of molecular free SO2 needed to protect a wine from
> spoilage and oxidation is roughly 0.8 ppm. At pH 3.2 it takes about 20
> ppm free SO2 to produce 0.8 ppm molecular SO2. At pH 3.6 it takes about
> 60 ppm free SO2 to produce that same 0.8 ppm molecular SO2.
>
> Tom S
>

Thanks.
Gerald Todd
> wrote in message
oups.com...
> Todd,
>
>> At what points should you test for SO2?
>
> Throughout the winemaking process.
>
>> Also, I've read about the
>> relationship between pH and SO2, which leads to my next question- If
> you
>> test and determine that both SO2 and TA need adjusting, is there any
>> standard way of adjusting them?
>
> You should firstly adjust TA, and then adjust SO2 depending on the pH.
>
>> The way I understand it, free SO2 will go up as pH goes down.
>
> The lower the pH, the more molecular SO2 will dissociate. This is the
> primary form which protects the wine.
>
>> Should you adjust the pH and re-test (this seems to be the way as I
> see it)?
>
> Adjust SO2 depending on whatever the pH happens to be.
>
>> I suspect the answers to these questions vary widely as to whether
> you use
>> kits or fruits, etc.
>
> The above is relevant for all wine - whether from fruit or kits.
>
> You may find the following article helpful:
> http://members.tripod.com/~BRotter/SO2.htm
>
> Ben
>

Gerald,
I can email you an Excel spreadsheet that graphs the relationship, it's
small. Just email me if you want a copy.
Joe

Gerald Todd wrote:
> Thank for the info. Just what I was looking for.
>
> Gerald
Todd
> "Tom S" > wrote in message
> ...
> >
> > "Gerald Todd" > wrote in message
> > news:1108751775.78920acfb063b537ea4751dda3f090f1@t eranews...
> >> At what points should you test for SO2?
> >
> > Right after fermentation and just before bottling. If you're
barrel
> > aging, you need to check it every few months too.
> >
> > Also, I've read about the
> >> relationship between pH and SO2, which leads to my next question-
If you
> >> test and determine that both SO2 and TA need adjusting, is there
any
> >> standard way of adjusting them?
> >
> > TA first; then check the pH and adjust the free SO2 according to
that.
> >
> > The way I understand it, free SO2 will go
> >> up as pH goes down.
> >
> > Not true. Free SO2 is independent of pH within the normal range
for
> > wines. You're thinking of _molecular_ free SO2, which IS pH
dependent.
> >
> > The three forms are (1) total SO2; (2) free SO2; (3) molecular
free SO2.
> >
> > Total SO2 is just what it sounds like: all SO2 in the wine. Much
of that
> > total is bound to other things in the wine in such a way that it is
not
> > available to protect the wine.
> >
> > Free SO2 is available to dissociate into molecular free SO2, but
that is a
> > pH dependent phenomenon. The lower the pH, the more this
dissociation
> > occurs. The amount of molecular free SO2 needed to protect a wine
from
> > spoilage and oxidation is roughly 0.8 ppm. At pH 3.2 it takes
about 20
> > ppm free SO2 to produce 0.8 ppm molecular SO2. At pH 3.6 it takes
about
> > 60 ppm free SO2 to produce that same 0.8 ppm molecular SO2.
> >
> > Tom S
> >