H2s odor still lingering

Not sure how that would help, I think you might want to consider Copper Sulfate. An old trick to add a little copper to the wine was to rack it through some copper tubing but you are running out of time if this has been going on for months. Copper in foodstuffs is considered a poison at some point so it's nothing to fool around with.

Margalit describes a simple procedure to see if copper sulfate will work in 'Winery Technology and Operations'; if you can't get a copy of it Ii can sum it up in a post.

Joe

Rick wrote:

Sounds great but I've had and treated H2s a couple of times in the past with quick positive results but this time the wine has a slight musty odor with a hint of H2s so I figured (I'm not a chemist) that somehow the main problem has been taken care of but there is some sort of H2s residue hanging on that may have to be treated in a different way, am I on the wrong track? If copper is the way to go I'm more than willing to give it a try also I will try and find a copy of Winery Technology and Operations as soon as I post this message.

Thanks, Rick

Joe Sallustio wrote:

The yeast not being happy during primary fermentation (high H2S consistent with the fermentation going reductive) may have led to some cap spoilage, if it started to dry out at any time during primary fermentation. Did your primary fermentation go very slowly? That could explain the mustiness.

Also, leaving the fruit 'skins' in contact with the wine for too long can add a mustiness to wine. I did this intentionally as experiments in extreme extended maceration (3 months and 6 months) of zinfandel wine. The wine was good except for a hint of ethyl acetate (overripe pineapple smell) after 3 months and the beginning of mustiness caused by the skins starting to break down (in addition to the ethyl acetate) after 6 months.

Another cause of mustiness would be Brettanomyces contamination. Brettanomyces spores are everywhere, just waiting for insufficient sanitation practices in preparing the fermentor to get growing.

The other earthy mustiness I'm familiar with is TCA (trichloroanisole), also know as 'corked' wine. That has been traditionally associated with either tainted cork used in bottling, but can also be caused by having damp wood or cardboard in your 'winery', especially when bleach is used for sanitation.

All four of these musty smells are the byproducts of different kinds of fungus.... nature's most efficient decomposers.

Gene

Rick wrote:

Assuming for a minute that the problem is solely H2S, then Rick is likely faced with H2S that has already progressed to mercaptans or worse. Assuming that is 'simply' H2S, he can try to remedy with copper sulfate - but needs to be very careful; this is deadly stuff. To treat a small quantity like that, he will need to measurements of grains - not grams. The Margolit book is the best guide.

I had a similar problem this last year with some Syrah. I had about 20+ gallons in 4 large carboys (6.5's and one 5) The H2S did not become apparent until a week or so into secondary. Because it appeared in all but one carboy, I am still perplexed as to cause (if it was in primary - why wouldn't it show in all 4 carboys? If in secondary, why in three out of 4? hmmm). anyway, tried a splashy racking, which reduced it, but didn;t solve it. I then spent a couple weeks learning about copper sulfate and then trying it. Too late. I ended dumping all but the one carboy. I now have 5 gallons of wonderful Syrah sitting in a carboy with an oak stave, and regret the loss of the rest.

Figuring that prevention is better than cure, I've been making as many plans as I can to avoid this problem this year. Adding 'super food' as well as DAP during primary; increasing punch downs from twice to three times daily. Other than that, not sure what else i can do other than monitor daily and 'splashy' rack at the first sniff of problem.

any ideas?

Sounds like you have a workable plan, I do that and haven't had issues recently.

Joe

Thx Joe - your advice is always appreciated.

Yes it sounds as if it may be too late but I'm on vacation this week and would like to try and remedy this asap which will means I will not get the book in time.

I picked up a 10g container of blue crystals Cupric Sulfate Crystals CusO45H2O at the local homebrew shop but they didn't have any info on how to use it and there's no user info on the container so I dug around the internet and found an article that said (a 0.1% solution added at about 0.5% ml per gallon will give about 0.3% ppm but do not exceed .05% copper).

It also read that the copper will settle to the bottom in a black form but recommended fining with bentonite after racking.

If your comfortable giving me the info on how to come up with this measurement I'd appreciate it and will most likely do a trial starting with 1/2 the recommended amount.

Actually I made 3 batches of blackberry 2 using D47 and one with 71B ending up with 6 gallons each in secondary and all developed H2s most likely due to the Pot Meta I added before hand to kill off bacteria but I did aerate and add DAP beforehand and a smaller amount on a daily basis when stirring, nothing to punch down on this one because I added the Pot Meta and let set for a couple of days gently stirring twice a day then extracted the juice which made life a whole lot easier bypassing all the fluff when transferring from primary.

Also on the sanitary end I've made well over a hinder batches of beer and about 25 batches of wines and meads knock on wood I never had an infection problem in the past ( I'm a sanitary nut) but I guess you never know when the bug will strike, hopefully the slight musty odor will disappear after treatment or a transfer or two along with some bulk aging.

Rick

Joe Sallustio wrote:

Yes it sounds as if it may be too late but I'm on vacation this week and would like to try and remedy this asap which means I will not get the book in time.

I picked up a 10g container of blue crystals Cupric Sulfate Crystals CusO45H2O at the local homebrew shop but they didn't have any info on how to use it and there's no user info on the container so I dug around

the internet and found an article that said (a 0.1% solution added at about 0.5% ml per gallon will give about 0.3% ppm but do not exceed .05% copper).

It also read that the copper will settle to the bottom in a black form but recommended fining with bentonite after racking.

If your comfortable giving me the info on how to come up with this measurement I'd appreciate it and will most likely do a trial starting with 1/2 the recommended amount.

Actually I made 3 batches of blackberry 2 using D47 and one with 71B ending up with 6 gallons each in secondary and all developed H2s most likely due to the Pot Meta which I added before hand to kill off bacteria but I did aerate and add DAP beforehand and a smaller amount on a daily basis when stirring. The fermentation appeared to go well and nothing to punch down on this one because I added the Pot Meta and let set for a couple of days gently stirring twice a day then extracted the juice which made life a whole lot easier bypassing all the fluff when transferring from primary.

Also on the sanitary end I've made well over a hundred batches of beer and about 25 batches of wines and meads knock on wood I never had an infection problem in the past ( I'm a sanitary nut) but I guess you never know when the bug will strike, hopefully the slight musty odor will disappear after treatment or a transfer or two along with some bulk aging.

Rick

Joe Sallustio wrote:

Rick, Winemakers use one percent copper sulfate solutions ( 1 gram copper sulfate in 99 milliliters of water) to remove H2S and mercaptan stench from wine. The reaction is very quick. Put 50 ml or wine in a glass, add a drop of 1% solution and stir. If the stench does not disappear, it is _not_ H2S or mercaptan. More info here

Lum - two questions;

1. there is a third structure that develops after mercaptans (can;t remember right now) do you know of such?
2. I was of the understanding (mistaken?) that the Cu sulfate effected only the H2S - NOT the mercaptan structure, nor the ensuing (above). Is that wrong?

Ric,

The "third structure" is disulfide.

H2S is a stinky gas. If the H2S is not removed from the wine in a few weeks, the H2S will react with alcohol in the wine and form mercaptan. If the wine containing mercaptan is aerated, the mercaptan will form disulfide. H2S and mercaptan will react with copper and form copper sulfide. Copper sulfide is a solid. It has no odor and it precipitates out of the wine. Unfortunately, copper will not react with disulfide directly. But, ascorbic acid (vitamin "C") is sometimes added to wines containing disulfide. The ascorbic acid breaks the disulfide bond and converts the disulfide back into mercaptan. Then the mercaptan can be removed with copper.

BUT, the ascorbic acid-disulfide reaction time is very slow (months not weeks). So, treating a wine containing disulfide can be a very frustrating process and many winemakers give up too soon.

Lum

Thanks Lum - that helped a lot.

If you're still browsing this thread I have, as always (!) more questions; Does the disulfide still smell? Last season, I tried to aerate some stinky merlot, didn;t work, so I treated with Cu sulfate, per Margalit. Still didnlt work (still rotten egg smell). After a few weeks, no change, so I dumped it. Assuming it was disulfide, I am now thinking that possibly I could have treated with ascorbic acid, then Cu sulfate, and left it a while longer.

dang it - dumped about 35 gallons of wine.

Compound Aroma Threshold (ppb) _____________________________________________________________ Hydrogen Sulfide Rotten Egg 0.9-1.5 Ethanethiol Burnt match 1.1-1.8 Methanethiol Rotten cabbage 1.5 Diethyl Sulfide Rubbery 0.9-1.3 Dimethyl Sulfide Canned Corn 17-25 Diethyl Disulfide Garlic 3.6-4.3 Dimethyl Disulfide Cooked cabbage 9.8-10.2

From: Sulfide Sensory Thresholds and Aroma Descriptions ng/ml ppb. Produced By Enological Technical Services. St. Helena, CA

Ric wrote:

Very informative - thank you!

Thanks for the info and thanks to all that helped with this one, I learned alot from this thread also I did order Margalit's book.

Thanks again, Rick

Lum Eisenman wrote: