HELP! Rotten Eggs in my FWK Riesling

[RylanJacobs]

Racked my FWK Riesling today. 21-day cold ferment <68F.

The wine is gothic black thanks to carbon powder, but shows signs of clearing to gray at the top.

Followed instructions explicitly. Checked SG on 7/5 and it was 1.000. Thought about racking at that time, but instructions explicitly call for 21 days before racking.

I saw in a previous thread on this forum where Matteo called out an individual for not following his instructions and waiting a full 14-21 days before racking and the had trouble with clearing.

As soon as I popped the airlock it was obvious….like I stuck my nose in a dang sewer. Rotten eggs and LOTS of it.

I splash-racked to secondary which seemed to help. Rotten eggs went from overwhelming to subtle…but still obvious. By the end of the rack I was getting green apple and some other fruit notes. H2S still present though. I decanted a glass for about an hour and it definitely improved, but not eliminated.


What are my next steps? I degassed, added kmeta/sorbate, and finished with K/C about 2 hours apart.

I’m genuinely concerned because I followed the instructions explicitly and it doesn’t seem like this has happened with kits before. I disagree with the FWK instructions and believe racking should occur when the SG indicates….not some arbitrary day after inoculation. I’m that case, I would have racked over a week ago when I was at 1.000. Today I’m at 0.995.

Any advice and tips is appreciated. Thanks!

 

[winemaker81]

Add another dose of K-meta and rack again.

That may solve the problem. If it doesn't, you need to get a product such as Reduless, which will eliminate it.

If you get an unpleasant aftertaste, that is mercaptans. The solution for that is ascorbic acid. I had this happen a few years ago -- it took 6 months to settle out, but the wine is good to this day.

 

[RylanJacobs]

Thanks! I’ll rack again tomorrow. I’ll add K-Meta and splash rack.

My wife was unable to detect the smell after the racking. She said “wow, that smells like apples!” Once I mentioned the possibility of H2S her response was “maybe a little bit.”

I might be able to get away with just a second rack, but I already have Reduless added to my cart just in case.

Thanks!

 

[winemaker81]

If the stench is that reduced. you may have it kicked. Good luck!

 

[Rice_Guy]

I would treat with Reduless anyway. The sulfur compounds are detectable at parts per trillion. Fruity aromatics are detected at parts per billion so they easyly mask the good stuff. Normal in the population the gals can pick smells out better than guys. You may be a super smeller which means you can make wine without all the lab testing I do.

This is a good learning curve to be on.

 

[RylanJacobs]

I did an aggressive splash-rack this evening and added K-meta. When I removed the airlock on the carboy, I got a beautiful bouquet of apples and canned peach.


Then I did an aggressive splash-rack.......the rotten eggs filled the entire garage. It was noxious. My wife noticed the smell within about 10 feet, whereas yesterday it was nearly undetectable. I

Reduless has been ordered. Will apply when it arrives next week.


Anything I should do between now and adding the reduless next week?

 

[Rice_Guy]

I did an aggressive splash-rack this evening and added K-meta. . . . . .
Anything I should do between now and adding the reduless next week?

What you have is stressed yeast (example low nutrition or high temperature) which is producing H2S. This is a sulfur compound. Metabisulphite is also a sulfur compound. Some journal papers relate that adding excess sulfur increases the risk of producing stinky sulfur. ,,, reduced flavors.

Splash racking incorporates oxygen into the wine. Oxygen reacts with ethyl alcohol creating acetaldehyde. At low levels this produces sharp green apple notes. At high levels this produces a burn in the back of the throat when swallowing. I know this sounds contradictory but minimize exposure to oxygen and keep your SO2 levels up to minimize oxidation flavors.

wine making is an art

 

[winemaker81]

Anything I should do between now and adding the reduless next week?

I'd stir, gently, every couple of days, to drive off the H2S that is present. If you stop smelling it, stop stirring.

K-meta and H2S are very different compounds, which act differently. If you add too much K-meta, you'll smell a burnt match smell, which is better than rotten eggs. Excess free SO2 (from the K-meta) will dissipate or get used up.

A few days after adding the Reduless, fine the wine to ensure the copper compounds are precipitated out. The following post is my notes from a 2020 batch that developed H2S, and how I treated it.

https://wine.bkfazekas.com/2020-red-blend-second-run/
Note regarding ascorbic acid -- determine how much you need, then use a lot less, as it's very acidic and you can produce a sharp wine very easily. It took 6 months for the wine to fix, but that wine is fine today.

One of my 2022 Tempranillo batches (I ferment in 4 lug batches) developed H2S, but I caught it very early and eradicated it without Reduless. The detection was on 10/12/2022 (heading in my notes).

https://wine.bkfazekas.com/2022-grape-wines-in-detail/
My wife detected the H2S a day sooner than I did, but she's not a winemaker and to her all fermentation smells are nasty, so she didn't mention it. For future reference, I've asked her to tell me if she smells rotten eggs!

I'm using mostly non-H2S producing yeast with my wines, and if I use a high nutrient requirements yeast, it will have more than enough nutrients.

This is the first time I've heard of H2S in a kit wine, but FWK doesn't use the typical EC-1118, which doesn't produce H2S. I expect that is yet another reason why kit vendors typically use EC-1118.

 

[RylanJacobs]

What you have is stressed yeast (example low nutrition or high temperature) which is producing H2S. This is a sulfur compound. Metabisulphite is also a sulfur compound. Some journal papers relate that adding excess sulfur increases the risk of producing stinky sulfur. ,,, reduced flavors.

Splash racking incorporates oxygen into the wine. Oxygen reacts with ethyl alcohol creating acetaldehyde. At low levels this produces sharp green apple notes. At high levels this produces a burn in the back of the throat when swallowing. I know this sounds contradictory but minimize exposure to oxygen and keep your SO2 levels up to minimize oxidation flavors.

wine making is an art

I suspect you are correct that the apple notes are really acetaldehyde. I added 1/4 tsp k-meta yesterday during the racking.

Is there a way to measure or monitor So2 levels without doing a lab analysis? I don't have the necessary equipment. I've just been doing 1/4 tsp K-meta.

 

[RylanJacobs]

I'd stir, gently, every couple of days, to drive off the H2S that is present. If you stop smelling it, stop stirring.

K-meta and H2S are very different compounds, which act differently. If you add too much K-meta, you'll smell a burnt match smell, which is better than rotten eggs. Excess free SO2 (from the K-meta) will dissipate or get used up.

Thanks, Bryan. Is it possible to add too much SO2? Does it always dissipate?

A few days after adding the Reduless, fine the wine to ensure the copper compounds are precipitated out. The following post is my notes from a 2020 batch that developed H2S, and how I treated it.

MoreWine! is going to have Reduless at my door on Monday. Instructions say to rack after 72 hours. I may let it go a little longer, add K/C, and then rack.

I'm using mostly non-H2S producing yeast with my wines, and if I use a high nutrient requirements yeast, it will have more than enough nutrients.

This is the first time I've heard of H2S in a kit wine, but FWK doesn't use the typical EC-1118, which doesn't produce H2S. I expect that is yet another reason why kit vendors typically use EC-1118.

FWK Riesling comes with D47.

In the future, I plan on using non-H2S yeasts only. This seems like a simple solution to me.

 

[winemaker81]

Thanks, Bryan. Is it possible to add too much SO2? Does it always dissipate?

Yes, but the allowed amount according to the USDA is very high. You could add another dose, but I'd do that only as a last resort.

MoreWine! is going to have Reduless at my door on Monday. Instructions say to rack after 72 hours. I may let it go a little longer, add K/C, and then rack.

That sounds good. I added K&C 4 days after the Reduless, then racked 4 days later.

 

[Raptor99]

In my experience, it is not usually necessary to measure SO2. But if you want to do it, you can use this: https://www.amazon.com/E-C-Kraus-4N-0CG1-444L-Titret-Making/dp/B00838RXU6 I used this kit for a while, then I decided that that level of precision is not necessary. Before bottling, I just assume zero free SO2 and add the recommended amount of Kmeta based on pH.

I don't think that SO2 will remove H2S. According to my understanding, splash racking releases the H2S gas. @Rice_Guy does it also oxidize the H2S? I'm not sure about that.

The reason to add Kmeta is that the splash racking will introduce oxygen, which needs to be removed from your wine. So it's like taking one medication to deal with the side effects of another. All you experts, feel free to correct me if I am wrong.

 

[winemaker81]

I don't think that SO2 will remove H2S.

Actually, it does. The chemical equation is SO2 + H2S = S + H2O

SO2 (K-meta) is used as it reduces most contaminants in wine.

In my experience, it is not usually necessary to measure SO2.

Ditto. Like you I assume zero free SO2 and add 1/4 tsp per 19-23 liters at each racking (post-fermentation), at 3+ month intervals during bulk aging, and at bottling time.

 

[Raptor99]

Actually, it does. The chemical equation is SO2 + H2S = S + H2O

What happens to the elemental sulfur? I don't imagine that it is just floating around in the wine.

 

[winemaker81]

What happens to the elemental sulfur? I don't imagine that it is just floating around in the wine.

I expect it precipitates. I had no problems with the 2 instances of H2S I had.

 

[Rice_Guy]

elemental sulfur is very reactive, it may be generated but likely stays in the system. Copper sulfate precipitates and needs to be pulled out.
Excessive copper is toxic.
Look at the AWRI. The ascorbic acid procedure is treat with ascorbic wait 24 hours for mercaptans to be reduced > treat again with ascorbic > wait for it to react again > treat with copper sulphate (Redulus yeast) > wait 72 hours > rack off the copper. This is not a fun procedure/ I don’t know anyone who has tried it.

My quick and dirty is to add 0.2 gram K meta per gallon every time I rack or manipulate a wine. Red grape has polyphenols so there may be some free SO2. Whites and country wines may read zero or have a trace of free SO2. If I was using the Winemaker magazine.com calculator I would assume the test number is zero.
I have become a big fan of tannin / polyphenols since someone in the vinters club identified reductive flavor in my wine.

We are home wine makers, we can ignore a 200 ppm total addition guideline. If you run to 100 ppm free SO2 folks should be able to identify a “sulfur match” flavor. BUT free SO2 is reactive and if the wine is aged a year it won’t be that high. ,,, ie time can fix too much. Practically speaking if you can taste it you have put too much in. Do you identify that flavor?
The only time I have over done it was when treating “flowers” and added 100ppm. ,,, but ,,, some folks are super sensitive to sulfur taste.

Anyway I don’t think treating with SO2 is a practical way to reduce acetaldehyde flavor. A little adds complexity to your wine, actually nice. Having enough to produce the burn when swallowing is a lot.

 

[Swedeman]

The chemical equation is SO2 + H2S = S + H2O

I fixed it for you:

SO2 + 2H2S -> 3S + 2H2O

;-)

 

[vtoddw]

Racked my FWK Riesling today. 21-day cold ferment <68F.

The wine is gothic black thanks to carbon powder, but shows signs of clearing to gray at the top.

Followed instructions explicitly. Checked SG on 7/5 and it was 1.000. Thought about racking at that time, but instructions explicitly call for 21 days before racking.

I saw in a previous thread on this forum where Matteo called out an individual for not following his instructions and waiting a full 14-21 days before racking and the had trouble with clearing.

As soon as I popped the airlock it was obvious….like I stuck my nose in a dang sewer. Rotten eggs and LOTS of it.

I splash-racked to secondary which seemed to help. Rotten eggs went from overwhelming to subtle…but still obvious. By the end of the rack I was getting green apple and some other fruit notes. H2S still present though. I decanted a glass for about an hour and it definitely improved, but not eliminated.


What are my next steps? I degassed, added kmeta/sorbate, and finished with K/C about 2 hours apart.

I’m genuinely concerned because I followed the instructions explicitly and it doesn’t seem like this has happened with kits before. I disagree with the FWK instructions and believe racking should occur when the SG indicates….not some arbitrary day after inoculation. I’m that case, I would have racked over a week ago when I was at 1.000. Today I’m at 0.995.

Any advice and tips is appreciated. Thanks!

I personally don't make kits anymore as they all had a weird sour / sweet / funky flavor to them that I can't get past and find it hard to accurately describe. For the record I've only made master vintner kits, so maybe FWK are better as people have stated. That said, when I did make them I followed the instructions to a T and I also took issue with the number of days they stated I should wait in secondary before racking. It stated something like 12 to 21 days and my wines were dry from primary to .994 in 5 days, possibly due to the temperature of my fermentation closet... For the first kit, I waited the full 12 days. For the following 3, since I'd already made wine with fresh grapes a few times and felt I knew better, I racked off gross lees a couple of days after the wine went dry for fear of H2S issues. In all cases, the wine turned out about the same.

I never actually had H2S issues with my kits. I have however, had what I think may be mercaptan issues with some of my fresh grape wines since, the smell isn't like rotten eggs but rather like burnt rubber or asphalt. This smell would start out strong during the first 3 months of bulk aging but would pretty much dissappear without any intervention on my part except standard racking every 3 months for a total of 9 months before bottling.

When I first detected these smells I explored all my options I could find on the web and considered dumping it. Years later I'm glad I didn't as the wine is totally fine and I'm not concerned about negative health effects from drinking residual copper or other toxic leftovers. So my point is, when it comes to wine making, racking and patience fixes most things, but that's just my two cents.

 

[Peggy Billingsley]

Thanks, Bryan. Is it possible to add too much SO2? Does it always dissipate?

MoreWine! is going to have Reduless at my door on Monday. Instructions say to rack after 72 hours. I may let it go a little longer, add K/C, and then rack.

FWK Riesling comes with D47.

In the future, I plan on using non-H2S yeasts only. This seems like a simple solution to me.

What is K/C?

 

[winemaker81]

What is K/C?

Kieselsol and Chitosan, 2 very common fining agents. They are packaged in all the kits I'm familiar with, and marketed under a couple of brand names such as Dual Fine (although I think this name is no longer used).

One is negative ions and the other positive, and they work VERY well in conjunction.

A while back I started using "K&C" instead of typing the names out, since I'm very lazy (odd for a 60+ wpm touch typist), and it's caught on.