Richard Kovach wrote:
I have a red wine that about a month ago developed a bad H2S problem,
because I got too busy and left it on the gross lees far too long. I
treated it with 1% CuSO4 soln until the H2S odour seemed to be gone.
I've been checking on the odour of the wine since, and it's been
reasonable. However today I sampled it and it seems to have a slight
but disturbing off note that I would say is best described as "burnt
rubber". It seemed to be more of a taste perception than odour, but
perhaps that's because I currently have a cold.

I tried searching the newsgroup archives on this but I'm not convinced
I found conclusive info. Is the burnt rubber problem caused by
disulfides as an old post suggested? If so, should I treat with
Ascorbic acid? Are there risks of making the wine worse by using
ascorbic acid and more copper?

I've been planning all along to blend this carboy of wine with another
of Merlot, and in the blending test I did today I couldn't seem to
detect the problem even though it was quite noticeable prior to
blending. My tendency would be to try and treat the problem before
blending in case it later spoils the entire lot, but I'd appreciate
advice from others with more experience with this.

Thanks in advance,
Richard

For what it's worth, as a brewer of beer, burnt rubber is associated
with yeast autolysis. I don't know if this could collerate to wine.

Brewer Bob