Don,
My two best sources on this question are Lum Eisenman and Ben Rotter.
You can find some good information on this question at Ben Rotter's
site:
http://members.tripod.com/~BRotter/
Firstly to clarify, your comment on the dosage of H202 from Jackisch
that "0.7 ml of 3% H2O2 to lower it (I think) 20 ppm" should be
expressed with the quantity being treated in this case I believe it is 1
gal. Also, when I try to verify the calculation it appears he is
referring to 0.7 ml lowering 1 gal by only 10 ppm's. When using H202
you need to be very careful on the dosage. I believe he refers to 1 gal
that I assume is a U.S. gal (3.785 liters) and not an Imperial Gallon.
According to my calculations .18 ml (actually .17556 ml) of 3% H202
lowers 1 liter of wine by 10 ppm's free SO2. Again, I think you should
check through your own calculations but I am quite confident of these
numbers.
The bottom line is:
- Each .18 ml of 3% H2O2 will lower 1 liter by 10 mg/l free SO2.
- Testing the SO2 level before and after H2O2 addition is advised.
- H2O2 should be added slowly.
- There is a limit in the amount of SO2 that can be added as the
reaction at low levels produces insignificant amounts of H2SO4 (sulfuric
acid) but if too much is added a bitter taste will appear in the wine.
You can use the level I cited above to check the Jackisch dose although
I expect they are quite close.
Good luck,
Glen Duff
-----------
Don S wrote:
> I don't have a SO2 tester but what is the typical SO2
> level after adding a kit's potassium metabisulfite?
>
> The kit had slowed right down to a bubble every minute
> of two and when I check it a few weeks later it had
> stopped. Being somewhat close to an bonehead 
I assumed
> fermentation was done and added the potassium meta. Now
> I realize it was stuck at 1.010. I've tried adding yeast
> nutrient, using EC-1118 and a warming belt to heat it
> up to 70F, and a splash racking. No luck. I forget the
> exact numbers but Philip Jackisch book recommends adding
> 0.7 ml of 3% H2O2 to lower it (I think) 20 ppm. In any
> case, I need to know the ballpark level right now.
>
> It's a Pinot Gris Kendall Ridge kit. Is there another
> possibility for the stuck fermentation?
>
> Don
>