| The possible causes of hydrogen sulfide contamination a

* Too much sulfites, usually the result of grapes being dusted
with too much sulfur during the growing season
* Lack of proper nutrients (nitrogen, yeast hulls) during
fermentation
* Yeast combining with various forms of sulfur (some folks swear
that Red Star Montrachet yeast is notorious for causing H2S, but we've
never experienced this ourselves)
* Bacterial contamination due to poor sanitation technique
|

I'm not using grapes, and I doubt what I am using was sprayed.
I washed eveything before hand. I'm thinking it's a lack of nitrogen
or the yeast. I only used one packet of yeast and split it between the
two batches. Of course it could still be a contamination problem.

I added 1 campden tablet, and 1 tsp of yeast nutrient (with other
ingedients) the day before adding the yeast. I have no idea if my
nutrient has DAP.

One site says "Do not add DAP at the beginning of fermentation, as it
will overpower the yeast which has not yet had enough time to multiply
to full activity." and another says "A common cause of stinking
fermentations is a lack of nitrogen, and mild cases of H2S can often
be cured by adding a small quantity of DAP to the fermentation."

I'll tried the aeration last night, and added some nutrient. Don't
have a sulfide test kit, or any ascorbic acid or copper sulphate.

It smells better today, but still has a smell. Not so much a rotten
egg, now it's more of a whiskey smell. I'm not sure what to think.

The red sumac color is now more orangish.
Stu



On Tue, 04 Oct 2005 21:56:32 -0400, Bruce_Nolte_N3LSY&
wrote:


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