Rotten Egg Smell in Marquette Wine

[Khristyjeff]

I'm seeking your advice for fixing this wine.
I started Sept. 1, 2021 from fresh grapes. pH 3.23 and used Red Star Premier Classique yeast. Had some early smells so used Fermaid which seemed to work. Pressed and racked on schedule. End of October the H2S smell had returned. Tried splash racking which didn't help, so added 1.5 oz of Reduless in about 0.6 oz of water to the 5 gallon carboy and stirred. Racked off the Reduless after 72 hours. That helped.
Now the rotten egg smell has returned. I've read on the forum that ascorbic acid can be used in moderation but have mainly seen it associated with white wines. Does it help with reds also? I have more Reduless so could try that again if you thought that was the way to go.
My other issue is getting accurate measurements for small quantities like 1-2 grams of something. I don't trust my scale Any good conversions to teaspoons?
Thanks for your advice.
I'll tag @Rice_Guy since he's commented on this topic before.

 

[Jim Welch]

I can’t help you with the smell problem as I’ve not yet had that problem that wasn’t resolved with a nutrient addition but can recommend a good scale.
I have a Deering 2 g pocket scale I bought long ago. Not sure if they’re still made but just did a google search and they are available on eBay.

 

[winemaker81]

I used ascorbic acid to treat mercaptans formed as a byproduct of H2S. Use it lightly, as it's a strong acid. AFAIK, it's not for treating the H2S itself.

My suggestion is to first stir the wine hard to drive off the H2S. Run a fan and do it in a ventilated area. Next dose with K-meta, which will bind to any remaining H2S and render it harmless. I used a triple dose (2-1/4 tsp in 14 gallons wine).

If that doesn't work, then use more Reduless. I, too, lacked a fine enough scale, but the package said to use 0.4 to 0.6 g per gallon. I went with the middle ground (0.5 g), for a total of 7 g. This was 1/4 the package so I divided it in 4 equal portions (well, as equal as I could) and added 1 portion.

My notes from that wine are here.

 

[Khristyjeff]

I used ascorbic acid to treat mercaptans formed as a byproduct of H2S. Use it lightly, as it's a strong acid. AFAIK, it's not for treating the H2S itself.

My suggestion is to first stir the wine hard to drive off the H2S. Run a fan and do it in a ventilated area. Next dose with K-meta, which will bind to any remaining H2S and render it harmless. I used a triple dose (2-1/4 tsp in 14 gallons wine).

If that doesn't work, then use more Reduless. I, too, lacked a fine enough scale, but the package said to use 0.4 to 0.6 g per gallon. I went with the middle ground (0.5 g), for a total of 7 g. This was 1/4 the package so I divided it in 4 equal portions (well, as equal as I could) and added 1 portion.

My notes from that wine are here.

Thanks Bryan. Great information.

 

[oenophilosopher]

Go buy a $6, 24" copper tube, clean and sterilize it, insert it into the carboy. Stir gently for a few minutes, and let it sit for another 10-15.

 

[winemaker81]

Go buy a $6, 24" copper tube, clean and sterilize it, insert it into the carboy. Stir gently for a few minutes, and let it sit for another 10-15.

NO! Not just no, hell no!

Copper sulfate is poisonous, even in low doses. Thirty plus years ago I helped a customer pour a wine across new pennies as that was "conventional wisdom" at that time to address H2S. In today's internet, it's easy to discover that is a truly stupid plan.

If H2S occurs, use a product such as Reduless to keep the amount of copper within safe limits.

 

[oenophilosopher]

NO! Not just no, hell no!

Copper sulfate is poisonous, even in low doses. Thirty plus years ago I helped a customer pour a wine across new pennies as that was "conventional wisdom" at that time to address H2S. In today's internet, it's easy to discover that is a truly stupid plan.

If H2S occurs, use a product such as Reduless to keep the amount of copper within safe limits.

Calm down there, Mr. Dabbler. At no point did I recommend a copper sulfate addition. I said buy a copper pipe, or copper wire, and sterilize it prior to introducing it to the wine.
New pennies are mostly zinc and don't have but 2.5% copper in them; you would have to use pennies pre-1982, and even then, it wouldn't be enough to break the disulfide bond with a handful of unsanitary pennies. However this little "conventional wisdom" trick works for a science project in an H2S rich glass at a wine bar to 'wow' your patrons.
Mass-produced wineries commonly employ the use of copper sulfate as a "preventative treatment" for H2S and ethyl and methyl mercaptans, but you still have to add ascorbic acid afterwards, and then likely more SO2 post-treatment. If you are buying a $12 bottle of wine off the lower shelf of your supermarket, 50-1 odds it has had CuSO4 additions.
The OP said they already tried Reduless and had initial success but the H2S returned (which is not inconsistent with this product). And for that matter, Reduless is merely a mixture of inactivated yeast.. and copper. Less toxic than CuSO is still toxic. Adding more Reduless a year after ferment is not beneficial. If nutrients didn't fix it initially, and Reduless didn't correct it, then the resulting H2S is likely due the fact that 80-95% of H2S is in a bound form, and the addition of Reduless may have provoked more bound H2S than was removed after racking. Putting it back into an anaerobic vessel, like glass or steel will only further reduce the wine. This phenomenon of free vs bound H2S is still being studied. Ascorbic acid alone does not resolve H2S. Worth mentioning the recommended dosage of Reduless is 0.4-0.6 g/gal. in 10 times the water weight, seems the OP added less water in the mix than prescribed.

If I have an H2S issue, I typically go through steps. If it occurs near end of ferment, I would add healthy lees from a finished ferment as a nutrient rather than DAPP or Fermaid K or O. If it occurs post ferment, or post-malo I would 1st: rack and return the wine off the lees. 2nd: aerate by splash racking. 3rd: Use a copper pipe or wire and either rack through the copper or stir/soak in the wine. 4th: bubble CO2 or Nitrogen through the wine. 5th: add Reduless or Copper sulfate, after bench trials.

Reading material of interest:

1. Ugliano et al., 2011. JAFC 59: 2564-2572.
2. Bekker et al., 2016. Molecules 21, 1214

 

[Khristyjeff]

Calm down there, Mr. Dabbler. At no point did I recommend a copper sulfate addition. I said buy a copper pipe, or copper wire, and sterilize it prior to introducing it to the wine.
New pennies are mostly zinc and don't have but 2.5% copper in them; you would have to use pennies pre-1982, and even then, it wouldn't be enough to break the disulfide bond with a handful of unsanitary pennies. However this little "conventional wisdom" trick works for a science project in an H2S rich glass at a wine bar to 'wow' your patrons.
Mass-produced wineries commonly employ the use of copper sulfate as a "preventative treatment" for H2S and ethyl and methyl mercaptans, but you still have to add ascorbic acid afterwards, and then likely more SO2 post-treatment. If you are buying a $12 bottle of wine off the lower shelf of your supermarket, 50-1 odds it has had CuSO4 additions.
The OP said they already tried Reduless and had initial success but the H2S returned (which is not inconsistent with this product). And for that matter, Reduless is merely a mixture of inactivated yeast.. and copper. Less toxic than CuSO is still toxic. Adding more Reduless a year after ferment is not beneficial. If nutrients didn't fix it initially, and Reduless didn't correct it, then the resulting H2S is likely due the fact that 80-95% of H2S is in a bound form, and the addition of Reduless may have provoked more bound H2S than was removed after racking. Putting it back into an anaerobic vessel, like glass or steel will only further reduce the wine. This phenomenon of free vs bound H2S is still being studied. Ascorbic acid alone does not resolve H2S. Worth mentioning the recommended dosage of Reduless is 0.4-0.6 g/gal. in 10 times the water weight, seems the OP added less water in the mix than prescribed.

If I have an H2S issue, I typically go through steps. If it occurs near end of ferment, I would add healthy lees from a finished ferment as a nutrient rather than DAPP or Fermaid K or O. If it occurs post ferment, or post-malo I would 1st: rack and return the wine off the lees. 2nd: aerate by splash racking. 3rd: Use a copper pipe or wire and either rack through the copper or stir/soak in the wine. 4th: bubble CO2 or Nitrogen through the wine. 5th: add Reduless or Copper sulfate, after bench trials.

Reading material of interest:

1. Ugliano et al., 2011. JAFC 59: 2564-2572.
2. Bekker et al., 2016. Molecules 21, 1214

Thanks for the detailed answer. I have much to learn and enjoy reading different points of view!

 

[winemaker81]

At no point did I recommend a copper sulfate addition. I said buy a copper pipe, or copper wire, and sterilize it prior to introducing it to the wine.

Pouring an acid, such as wine, over copper dissolves an unknown amount of copper, which can be toxic. Using a calculated amount of a known product is safe (if the calculation is correct).

 

[papabearRN]

Splash rack a few times.