Stu Pedaso wrote:
> I have 3 batches going, added yeast on Sunday.
> 1 is a 2gallon apple and pear, using K1-V1116 it is foaming nicely but
> has a very funny smell. My wife says rotten, I say just a very strong
> alcohol.
>
> 2 is a 1gal sumac (may be high in tannin) has no foam. A small sample
> placed in a glass yesterday had small bubbles, like soda.
>
> 3 is a 1 quart banana trial. no foam either. just small bubbles.
>
> I used 71B-1122 on 2 and 3. Both have a funny smell, almost a rotten
> egg smell, but there is also a hint of working yeast and alcohol.
>
> I've only made one apple batch prior to these. and it smeledl much
> better than these. Any suggestions, does 71B-1122 hardly foam?
> Stu

You have come down with the dreaded Hydrogen Sulfide disease my friend!
Hydrogen Sulfide forms during fermentation when there is an excess of
Sulfur present on the grapes due to late spraying to prevent mildew, or
there are certain critical nutrients missing or in short supply in the
grapes. It has plagued winemakers since ancient times, and can be
sometimes difficult to deal with even today. Leaving especially whites
on the gross lees too long can cause this condition as well. I am still
learning how to deal with this, I discovered I had this problem in a big
way on my Chardonnay when I did the first racking. Phew! It was so
strong my eyes watered.

First, the bad news: If you don't deal with this problem quickly, you
might as well dump the wine down the sewer. What happens is that if the
H2S remains dissolved in the wine, it will react with Alcohol to form
Mercaptans, which in turn will form disulfides and polydisulfides, which
are almost impossible to remove from the finished wine.

The good news is, if you catch the problem early you can probably save
the wine. Hydrogen Sulfide is present as a gas in solution in the wine.
By just aerating it, you will remove much of the gas, but you also will
have to deal with the Mercaptans that are already forming in the wine.
I Googled for information on this topic, and came up with these links,
along with several other good links that concisely explain the problem,
and how to deal with it:

http://www.sdaws.org/Articles/Article4.htm
http://www.grapestompers.com/article...en_sulfide.htm
http://www.bcawa.ca/winemaking/h2s.htm