questions about sulfites
 

I have 2 questions:
1. When you test the sulfite level in a carboy, if you just dip the
titret into the top of a carboy, is this a reasonable sample? That is,
are sulfites so volatile that there might be different levels at the
bottom of a carboy than at the top?

2. I've often wondered why I'm being so exact with my sulfite
titrations. If I complete a batch of wine and age it in a carboy, I
find that I often have to add more sulfite over the course of a year. I
do all of the adjustments for pH. But if I know that I'm aiming for a
sulfite level of 40 ppm, based on pH, why not just add maybe 80 or 100
ppm at the onset and let nature take its course over the next year of
aging. The alternative is to shoot for 40, then have it decrease to 20
and not be noticed for several months. Does this make sense?

Thanks,

Lee

"Lee" > wrote in message
ups.com...
>I have 2 questions:
> 1. When you test the sulfite level in a carboy, if you just dip the
> titret into the top of a carboy, is this a reasonable sample? That is,
> are sulfites so volatile that there might be different levels at the
> bottom of a carboy than at the top?
>
> 2. I've often wondered why I'm being so exact with my sulfite
> titrations. If I complete a batch of wine and age it in a carboy, I
> find that I often have to add more sulfite over the course of a year. I
> do all of the adjustments for pH. But if I know that I'm aiming for a
> sulfite level of 40 ppm, based on pH, why not just add maybe 80 or 100
> ppm at the onset and let nature take its course over the next year of
> aging. The alternative is to shoot for 40, then have it decrease to 20
> and not be noticed for several months. Does this make sense?
>
> Thanks,
>
> Lee
>

This has been discussed before and I do not remember the reason but it is
not a good idea. I believe it was Lum that explained why but I am not sure.
If you do not get a good answer, try searching back through old threads with
google.

Ray

Ray Calvert wrote:
> "Lee" > wrote in message
> ups.com...
> >I have 2 questions:
> > 1. When you test the sulfite level in a carboy, if you just dip the
> > titret into the top of a carboy, is this a reasonable sample? That is,
> > are sulfites so volatile that there might be different levels at the
> > bottom of a carboy than at the top?
> >
> > 2. I've often wondered why I'm being so exact with my sulfite
> > titrations. If I complete a batch of wine and age it in a carboy, I
> > find that I often have to add more sulfite over the course of a year. I
> > do all of the adjustments for pH. But if I know that I'm aiming for a
> > sulfite level of 40 ppm, based on pH, why not just add maybe 80 or 100
> > ppm at the onset and let nature take its course over the next year of
> > aging. The alternative is to shoot for 40, then have it decrease to 20
> > and not be noticed for several months. Does this make sense?
> >
> > Thanks,
> >
> > Lee
> >
>
> This has been discussed before and I do not remember the reason but it is
> not a good idea. I believe it was Lum that explained why but I am not sure.
> If you do not get a good answer, try searching back through old threads with
> google.
>
> Ray

I believe it was TomS and the main reason was that when there is too
much sulfite, you can't evaluate how the wine is developing. Also,
there is a chance you're overshoot the addition and the sulfite never
drops to a decent level.

Pp

It is becasue the available SO2 dissapates at a rate like
(arbitrarily) 20% a day. It does not dissipate at a rate of say
(again arbitrarily) 2 grams a day.

So if you put twice as much in you will just lose twice as much as
day....so over the course of fermentation you will still lose it all.

This is complicated by acidity levels and other stuff, and I did not
feel like looking up the dissipation rates...but you can get the idea.