Re: H2s odor still lingering

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?



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:

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:

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:

I have a large batch of blackberry (18 gallons) that I started in early
April of this year which developed H2s in the primary, I splashed
transferred and treated with Bocksin but several months later I can
still notice a slight H2s odor?
Does anyone have a cure for this residual odor, I thought I read
somewhere in the past that treating with Potassium Sorbate may help but
can't remember any details.

Rick


.

Relevant Pages

  • Re: H2s odor still lingering
    ... The yeast not being happy during primary fermentation may have led to some cap spoilage, if it started to dry out at any time during primary fermentation. ... leaving the fruit 'skins' in contact with the wine for too long can add a mustiness to wine. ... If copper is the way to go I'm more than willing to give it a try also ...
    (rec.crafts.winemaking)
  • Re: H2s odor still lingering
    ... I've never had this problem, but I've been told that racking through a short, thin length of copper tubing sometimes works, or drop a small piece of copper in the wine for a few hours. ... with the fermentation going reductive) may have led to some cap spoilage, if it started to dry out at any time during primary fermentation. ... leaving the fruit 'skins' in contact with the wine for too long can add a mustiness to wine. ...
    (rec.crafts.winemaking)
  • Re: Hydrogen Sulfide - Rotten Egg Smell in Sauvigon Blanc
    ... Commercial wineries use copper sulfate for this purpose, but too much copper sulfate is toxic, so it must be done with caution. ... Also, some of the sulfur may be present in disulfide form, which smells like garlic or cooked cabbage. ... A simple way of removing H2S is to add enough copper sulfate to produce about 0.1 ppm of copper in the wine. ... The wine should be left undisturbed for several days after treatment so the copper sulfide will settle to the bottom of the container. ...
    (rec.crafts.winemaking)
  • Re: wine, hydrogen sulfide, copper sulfate
    ... "if you have a glass of wine showing some of these rotten egg, ... newer, more modern, sulfur reducing procedures. ... Now you mention food ... ... heavy metal poisoning from excess copper. ...
    (sci.chem)
  • Re: wine, hydrogen sulfide, copper sulfate
    ... "if you have a glass of wine showing some of these rotten egg, ... copper than newer ones and work better. ... <END QUOTE> ...
    (sci.chem)