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Re: hydrogen sulfide problem

I had read that ascorbic acid can be added to revert disulfides back to

> mercaptans to treat with bocksin or copper sulfate. Does anyone know how > long this takes and how long it should sit after adding copper before > filtering? Thanks. > Dave

Dave, The reaction time between ascorbic acid and disulfide is slow. At cellar temperatures, several months may be required to convert disulfide back to mercaptan. On the other hand, the reaction time between copper and H2S or mercaptan is fast. The reaction will complete about as fast as the copper can be mixed into the wine, so you can filter immediately. See Margalit, "Concepts on Wine Chemistry," page 320 and Zoecklein, "Wine Analysis and Production," page 175. lum

Reply to
Lum
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Do you know how long it takes to form disulfides? I figured out the problem maybe a week or two after I noticed the smell. I added Bocksin and that helped a lot but it still smells somewhat, even after adding a little bit more and sterile filtering, so the next step is adding copper sulfate I guess but I dont want to add it if its not going to work completely. So I guess I'll be sitting on it for a while. Maybe the Bocksin just didnt take all of it out and the copper will work fine. I guess I will find out. Thanks for your feedback. Dave

Reply to
gator

Dave,

I've heard that it can take a large dose of Bocksin to clear a Mercaptan problem so you may want to try a second treatment before you go with the copper.

CHEERS!

Aaron

Reply to
Aaron Puhala

This is a bit off-topic, but does anyone here know how concentrated H2S needs to be in the surrounding atmosphere before it is a health concern?

My latest job relates to natural gas production and some of the people I work with have experience out in "the field" (around well sites and gas plants). H2S is a common byproduct of natural gas retrieval. With their background, my co-workers were of the opinion that H2S at any detectable concentration is a health hazard (I don't remember exactly how or why).

Is the amount of H2S that can conceivably be produced by ferementing must safe to inhale, or should I look to ventilate the area immediately if I ever have an H2S problem in the future?

Thanks, Richard

Reply to
Richard Kovach

Richard,

Hydrogen sulfide is indeed poisonous. The Occupational Safety and Health Administration (OSHA) has established an acceptable maximum concentration of

20 parts per million (20 milligrams per liter) in the workplace, with a maximum level of 50 ppm allowed for 10 minutes.

Fortunately, our noses can detect very small quantities of H2S. Margalit in "Concepts in Wine Chemistry" (page 320) says the detection threshold in air is about 20 micro-grams per liter. So, our detection limit is about 1/1000 times the permissible level. I don't know how much H2S might be produced during fermentation. It can produce a BIG stench sometimes, so ventilation always seems like a good idea to me.

Regards, lum

Reply to
Lum

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