One of my 2003 batches (mixture of CA central valley Cab Sauv and
Alicante) has been bubbling away pretty steadily in the carboy with
what I thought was MLF (it's close to 3 weeks since it went dry). I
had been too busy to check it much the last 10 days, and when I
finally took a wiff there was a lot of H2S coming off. Since I had
some 1% CuSO4 solution handy from a couple of years ago when I had my
first H2S problem, I hit the wine with what should have been about
0.07ppm and racked off the lees. The lees themselves did not smell
very strongly of H2S.

Since that racking, there has been no detectable bubbling. I'm
curious as to whether the bubbling I saw could have been H2S being
produced rather than MLF. Or was it likely MLF, and the racking
and/or CuSO4 addition stunted or killed the MLF process? Or is 3 or 4
days just too little time to be seeing bubbles being given off again
(the tiny ones in the wine, not the airlock bubbling) even if MLF is
still active?

Thanks,
Richard

I've seen this before. I think CO2 can't push the airlock bubbler
until the wine is saturated with CO2. Racking releases the saturated
gasses and the slow MLF takes a while to re-saturate the wine. Can't
comment on the H2S, I hate that smell.

Dan


(Richard Kovach) wrote in message . com...
One of my 2003 batches (mixture of CA central valley Cab Sauv and
Alicante) has been bubbling away pretty steadily in the carboy with
what I thought was MLF (it's close to 3 weeks since it went dry). I
had been too busy to check it much the last 10 days, and when I
finally took a wiff there was a lot of H2S coming off. Since I had
some 1% CuSO4 solution handy from a couple of years ago when I had my
first H2S problem, I hit the wine with what should have been about
0.07ppm and racked off the lees. The lees themselves did not smell
very strongly of H2S.

Since that racking, there has been no detectable bubbling. I'm
curious as to whether the bubbling I saw could have been H2S being
produced rather than MLF. Or was it likely MLF, and the racking
and/or CuSO4 addition stunted or killed the MLF process? Or is 3 or 4
days just too little time to be seeing bubbles being given off again
(the tiny ones in the wine, not the airlock bubbling) even if MLF is
still active?

Thanks,
Richard