# Hydrogen Sulfide Problem



## Locke (Mar 3, 2011)

Hello!

I'm new to winemaking [hence being in this forum ] and, of course, am experiencing problems with my wine. I'm making three gallons of white and one gallon of red, both based on Welch's frozen grape juice concentrate [no preservatives, artifical flavors, etc.]

Primary fermentation in both batches went well; the yeast population grew, peaked, and died down, and I transferred it to a carboy as soon as it was ready. It tasted great already at that point!

However, now in secondary fermentation since last Thursday, I've noticed the distinct and -STRONG- smell of sulfur coming out of my airlock. I hope it's recent, since the wine has been in the carboy for some time now.

I've been reading and recognize the problem as hydrogen sulfide contamination, but am unsure of the cause. I properly sanitized all equipment at every step. Either way, my next step is to buy some copper mesh and run it through the wine several times, as well as rack it a few times to aerate the hydrogen sulfide. I've read that this helps, however, I have a few hesitations.

1. It's possible that not all yeast are dead yet, and having read a million articles on home winemaking, it seems like exposing the must to oxygen while in secondary fermentation is a serious no-no. However, now, in secondary fermentation, is when I'm having my hydrogen sulfide problem. 

2. I read about adding copper sulfate to the mix at a solution of <0.1%, but I'm nervous about this as it's a known toxin. I know winemakers do it, but if I could have my wine be as untainted as possible, I'd like to. This seems like a "will work" solution, but at a serious cost. 

3. My wine looks very yellow. It seems to have gotten more yellow as it's cleared, but that may be my imagination. What could be the cause of yellowing in secondary fermentation, if, in fact, this is happening?



If you have any other suggestions regarding fixing the hydrogen sulfide problem and/or yellowing [that are not in the textbooks... things that you've found just worked for you] I would be SO appreciative.  So far, the gallon of red wine seems to be smelling just fine. Hopefully that doesn't go sour, too 

Thank you so much!
-Gareth


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## cpfan (Mar 3, 2011)

Hydrogen sulfide (H2S) is a rotten egg smell. You said it was a sulfur smell. Not qute the same thing.

What liquid do you have in your airlock?

Steve


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## Locke (Mar 3, 2011)

It smells like rotten egg, the sulfur smell that's fresh and really pungent, not the sulfur smell that's similar to burning matches. If you've ever been to a natural hot springs, or have well water... it's that smell.

The water in the airlock is filtered city water, and it should be sterile. It's never come into contact with the wine, to my knowledge. What do you think it might be?

Gareth


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## winemaker_3352 (Mar 3, 2011)

Could be hydrogen sulfide in your wine.

The possible causes of hydrogen sulfide contamination are:

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

H2S contamination can be prevented if you:

Add proper amounts of sulfites to wine
If making wine from scratch (not from a kit), add a proper amount of yeast nutrient prior to pitching yeast (Fermax, DAP, etc.)
Use proper yeast for the wine you're making, and make sure it has not passed the expiration date or gotten too hot in storage.
Maintain sanitary conditions for your equipment and must (especially prior to pitching yeast)

I have read that you can do the steps below to rid the rotten egg smell:

First, measure the amount of sulfites in your wine using a test kit
If deficient, treat wine to 50 PPM sulfites
Rack and splash - rack your wine two or three times, being sure to splash it around a lot as the wine goes from vessel to vessel. The aeration (introduction of oxygen) will help counteract the H2S.
Put the airlock back on and wait a couple of hours or overnight. If it still smells like rotten eggs, keep going...
Get a piece of copper (i.e. copper flashing) from a home supply store.
Pour the wine over the copper so that it runs over the surface of the metal into a receiving vessel.
Fine or filter the wine.
By now, the sulfur smell should at least be greatly diminished. If you can still detect a smell (we've heard that humans can detect H2S in quantities as low as 2 parts per billion), you might try to use an egg white or a gelatin fining agent and fine your wine. Add normal amounts recommended by the manufacturer.
Filter wine through a tight filter.
When all else fails you can use copper sulfate on your wine. A 0.1% solution added at about 0.5 ml per gallon, will give you about 0.3 PPM copper sulfate in your wine. BE CAREFUL. Remember, this stuff is poisonous. DO NOT EXCEED 0.5 PPM of copper.
Fine your wine with a bentonite or Sparkolloid fining agent. This will remove all the copper sulfate.
Filter wine if necessary to remove fining agent.


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## robie (Mar 3, 2011)

I don't know your particular recipe. Did it call for a yeast nutrient to be added sometime after fermentation started?

I haven't made wine from Welches concentrate, but one of the main causes of H2S is lack of nutrient in the wine a few days after fermentation starts. Sometimes, a lack of oxygen during primary fermentation can also cause it.


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## Locke (Mar 3, 2011)

In my recipe, the yeast nutrient was added in the very beginning, along with the campden tablets, acid blend, etc. Primary fermentation went very well - at time of first racking to carboy and secondary fermentation, alcohol content was around 10%. 

It's during secondary fermentation now that I am having the odor problem. I just went to my hardware store and bought some copper tube and a copper sheet to run the wine against/stir it with. 

My main question is: is it okay to remove the wine from secondary fermentation and expose it to oxygen in order to take care of the problem? Or will that increase the chances of it turning into vinegar, or being spoiled in some way, or fermentation starting back up?

There's so much mixed information. Some people say do NOT expose to oxygen, some say it's fine, others say some but not much. 

Any help would be great!

Thanks
Gareth


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## winemaker_3352 (Mar 3, 2011)

How much campden did you add?

How much and when you added it in.


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## djrockinsteve (Mar 3, 2011)

When you expose wine to air, it is being exposed to oxygen and other gasses. This introduction of air can help to clear out any bad odors. Remember, the odor isn't "in" the wine, it's in the air molecules that are attached to the wine molecules. Racking or stirring can help remove off wanted odors.

Now, once those odors are removed you want to make sure that your wine is properly sulfited to protect your wine from oxidizing. Sulfite seperates and combines with air molecules and some escapes to fill the headspace etc. By doing this you are greatly reducing the opportunity for bacteria to attack and gain a foothold on you wine and begin to convert it to vinegar.

First, identify the problem
Second solve the problem.
Third protect your wine from additional problems.

If you believe it is what you think, remove a sample and stir with a piece of copper and see if it is corrected. It may not be noticed immediately.

If this works then treat all your wine.

Keep us posted on what you do and we can help you thru this. Don't get discouraged.


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## Locke (Mar 3, 2011)

Winemaker -- I'm not sure; I'll have to go home, check the recipe, and get back to you. The campden was added before primary fermentation occurred -- the directions in the winemaking recipe book [under frozen grape juice concentrate recipe] said to mix all ingredients together, and let sit for 24 hours before adding the yeast. This is what I did, and primary fermentation went well.

Should more campden have been added before secondary fermentation, to keep the must sterile? If so, that might be the first problem.



Steve -- I will try aerating the wine when I get home. I will probably do this in the process of siphoning it to another container, pouring it over the copper and stirring it with the copper rod. I'll test this on a small sample of the wine first.

When you say "make sure it's sulfited," what exactly do you mean? Do you mean adding more campden, potentially? Is there some way to test the sulfite levels without dropping another $50 on a testing kit? I'm a college kid and I'm trying to save money. And believe it or not, no, I'm not just doing this for the alcohol content!  I'm genuinely interested in the process.

Thanks for your help everyone, I will keep updating this thread as I make progress. I have no intent to give up -- all the way! I will make wine, I swear it! 

Gareth


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## winemaker_3352 (Mar 3, 2011)

No - I wouldn't add anymore campden until fermentation was complete.

Sounds like you added the right amount.

What yeast did you use? 

Also you sanitized the secondary vessel right?


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## BobF (Mar 4, 2011)

I've had two or three episodes of H2S. Each time I've been able to clear it up using the following:

1. Splash rack with sulfite solution addition.

2. Stir with a piece of copper. I use the fat copper wire used for grounding. Before stirring, I "shine" it up good with those copper-clad scrubbers.

3. Repeat #2 in a few days. Sometimes a third stir is done.

To prevent H2S, I've abandoned Montrachet and make sure I use the proper amount of nutrient, sometimes staggering the nutrient additions to make sure there is plenty of nutrient at the end of primary fermentation.

I also make sure I rack off of any gross lees in the secondary within just a few days - no more than 5 - 7.

So far these steps have made me H2S free for the last dozen or so batches.


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## Locke (Mar 4, 2011)

First off: I used Red Star Montrachet [of course -- in the brew shop it came down to "this one looks nice,"] which I've been reading more and more can provoke this H2S problem. 

What's odd to me, though, is that it seems to have happened after the yeast died in secondary fermentation... not during their peak or at any point during primary fermentation. Also, I used the same yeast [from the same package, actually] to ferment the gallon of red wine I have in a smaller carboy right now, and that one seems to be doing just fine.


~~~

Alright, so far here's what happened.

Last night I transferred the wine out of the carboy into the bucket that I used for primary fermentation. Everything sanitized, of course. It stank to high heaven... absolutely awful smelling once I opened the airlock on the wine.

I siphoned the wine into the bucket having it run along a copper sheet that I bought at a local hardware store. I then stirred the wine pretty vigorously, making it quite frothy [not CO2 froth; fermentation has ended] and it smelled pretty terrible. I actually let the copper sit with the wine overnight, hoping it would react with some of the H2S in the wine. 

This morning I smelled it -- initially after opening the bucket, the smell was bad, but that cleared and the H2S smell seemed much lighter, and I can even detect the scent of grape and alcohol again. Every hour or so I have been stirring the wine roughly with the copper, letting the bubbles that come to the surface clear away before stirring it again. The smell seems to be getting better, although I can't tell if it's just my mind tricking me or not. I tried some of the wine, and I could definitely detect the H2S [pretty strongly] still when it actually got into my mouth.

I'm tempted to order the Copper Sulphate to take care of the problem, but I want to wait a few more days. The wine itself seems fine aside from the H2S problem; I don't see any other signs of it spoiling or anything.



Thoughts along the way: could having fermented in a plastic carboy cause any problems? I used the culligan-style blue plastic water jug. The woman in the local brew shop said it should be an acceptable carboy; she makes wine as well, but I almost wonder if she's never even tried it in plastic.

What concerns me is that last night after cleaning out the dead yeast at the bottom of it, and rinsing it several times with detergent, the smell of H2S was still very present -- leading me to believe that the plastic is possibly porous, and something got into the pores of the plastic and contaminated the wine. Only after bleaching it with near-boiling water did the smell come out. Just a thought.


Thanks!

Gareth


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## Locke (Mar 5, 2011)

Another update:

After checking today, the wine is almost odor-free! I can't even believe it. The smell was SO unbearable only three days ago. I couldn't even get close without gagging.

I'm going to keep watching it, I wonder if adding more campden helped the problem. As always, diligence pays off!

I tried a bit of it; it's a bit tart yet, the flavor is a bit strong and needs to be aged more I think. Other than that... fantastic! Thanks for all the help!

Gareth


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## Wade E (Mar 5, 2011)

This yeast is very vulnerable to this but I use it often still aqs its a great yeast but you must use proper nutrients and energizer. It has its place in wine making and you can run into this same problem with other yeasts.


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## Eyeguy (Mar 15, 2011)

*Also have odd smell.*

Hi I am VERY new to wine making. I have read a lot but started just recently producing. I am using a CC red mnt Cab kit which began primary fermentation on 3/11 (3days). Since it is my first time I only followed the kit instructions. I did test the must though. It was lower acid 0.42 with SG of 1.131 and brix I dont have on hand at the moment.
Fermentation began well and is heavy now. Today I began to smell what I thought was the dreaded FAINT rotten egg smell...but after reading online I wondered if it is an early fingernail polish smell...something chemically mized with the wine. First I thought sulfur now maybe fingernail polish. But I also read about "kit smell"..now very confused since treatment is so different. This kit has a grape pack and I added it loose. I stir 3 times a day now in my 8 gal ferment bucket under air lock and so2 soln in lock. The kit currently has oak (french) shavings in it as well.
Any advice on what that smell could be and how to proceed..I dont want to over react but I dont want to blow it either


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## Runningwolf (Mar 15, 2011)

AHHHH thats the sweet smell of fermentation! Mix that with a bubbling air lock and its called heavenly.


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## Eyeguy (Mar 15, 2011)

*thanks*

this place is great everyone is so fast at responding.
Being new to wine I assumed the yeast would give off more of a smell like the yeast you get while making bread...kinda a dumb thought looking back now since these babies make ETOH that is in liquid form..


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## Wade E (Mar 15, 2011)

Each wine will have different smells, some you will love and some you may not be fond of.


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## Locke (Mar 16, 2011)

The smell my must gave off during primary fermentation [and the subsequent smell through my entire apartment] could be described as a bakery and winery rolled into one. The yeast smell was very strong, and it mixed with a grapey smell to produced a really wonderful smell, actually, that filled the whole hallway.

I detected the nail polish remover smell lightly when I transferred to secondary fermentation, but since then it seems to have cleared... keep us posted on how the smell changes, if it does! It might just be the smell of the new alcohol mixing with the other smells of the fermenting wine.


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## wallstreetmann (Sep 4, 2013)

One misconception I see alot of is the idea that there is a lack of oxygen at various times during wine making. There is always plenty of oxygen, it just can't be utilized in the presence of too much CO2. As a matter of fact, I've seen studies that suggest yeast won't produce alcohol unless oxygen is cut off some. Think of yeast as fish in your aquarium, an air stone is introduced to create bubbles that will bring the CO2 out so the suffocating fish can use the oxygen. Any movement, like waves, waterfalls etc.., will have the same effect. 
Hydrogen Sulfide is no different, it needs movement in the wine to be able to escape, the lees needs to be stirred up until it no longer can be a problem, best time to do this is while it has the CO2s help. I'm a believer in cork, wine needs to breath to a certain extent or it can become sulphurized, I would never use a seal on my bottles that could not breathe. Stir at least once a day until there are not enough dead, dying or stressing yeast to create a problem!

David


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