Off/Bad aromas,o something else.

[DAB]

My 2019 Petit Sarah Is now almost two month old. I tasted it today, it smells unpleasant...sort of, well, sulfur like...maybe--I think. However, it tastes fine, immature for sure, but the smell is undeniably not pleasant. I added some copper coins to it but I'm not sure 1.) if that's the right thing to do. 2.) why that works. 3.) if I should do something else.

edit: for some reason my browser is acting up...the title should be "Off/Bad Aromas" Sorry, I can't change the title.

 

[sour_grapes]

2) That works because sulfide compounds bind strongly to noble metals like copper
1) It is NOT the right thing to do, because wine is quite acidic, and can leach/dissolve copper. A little copper is fine, but a lot is unhealthy. ("The dose makes the poison.") You are adding an uncontrolled amount of copper to your wine.
3) Instead, use a product called Reduless or a careful, calibrated addition of copper sulfate.

 

[DAB]

Okay, thanks. I added the equivalent of about 8 pennies to 18 gallons of wine. I'll get some Reduless right away.

 

[user 36973]

I added some copper coins

Thankfully the composition of pennies is only about 2.5% copper (link). Copper dissolves in acidic solutions such as wine and can be toxic in excess. See here about how overnight acid exposure to excess copper will lead you to throwing up from copper poisoning.

As @sour_grapes said, reduless or simple copper sulfate solution will allow you do correctly dose your wine without poisoning you. Cheers!

 

[DAB]

Okay, I removed them...I get it. Shouldn't have done it, honesty, I didn't know. Now, next question: While I'm waiting to add the Reduless, what is/has happening/happened to the wine to give it that odor? It is as simple as adding the Reduless to remove the smell or...after having done so is there something that's happened chemically that has forever changed the wine's taste, body or quality?

Thank you for the information, I'm learning much from you guys and gals!

 

[user 36973]

what is/has happening/happened to the wine to give it that odor?

Yes thanks. This is really what we needed to pass on. The goal is not to have to fix problems but to prevent them.

Your yeast was stressed and it produced H2S as it freaked. Some yeasts (eg. RC212 or Montrachet) are well known as being hungry for yeast nutrients. Others are more forgiving. Regardless, stressed yeast can produce the rotten egg H2S aroma. High temperature and lack of nutrients are the primary factors.

You can prevent the H2S by providing upwards of 0.5-1g/L of a yeast nutrient such as diammonium phosphate (DAP) or one of the formulations that includes it at higher cost (eg. Fermaid). It is good to add it to your fermentation in pieces 2/3 and 1/3 through if possible. There are also yeast strains that are more forgiving or are claimed to not produce it at all.

 

[sour_grapes]

Thankfully the composition of pennies is only about 2.5% copper (link). Cheers!

Yes, but this is misleading to the point of being incorrect. As the quote you referenced says:

part1982-present – 97.5% zinc, 2.5% copper (Copper plated: Inclusive of bicentennial 2009 cent and Union Shield cent). [Emphasis added]

That is, the copper is all on the outside, where the wine can get at it. As far as the wine is concerned, the penny is 100% copper (at least until all the copper skin would be dissolved).

 

[4score]

Yes thanks. This is really what we needed to pass on. The goal is not to have to fix problems but to prevent them.

Your yeast was stressed and it produced H2S as it freaked. Some yeasts (eg. RC212 or Montrachet) are well known as being hungry for yeast nutrients. Others are more forgiving. Regardless, stressed yeast can produce the rotten egg H2S aroma. High temperature and lack of nutrients are the primary factors.

You can prevent the H2S by providing upwards of 0.5-1g/L of a yeast nutrient such as diammonium phosphate (DAP) or one of the formulations that includes it at higher cost (eg. Fermaid). It is good to add it to your fermentation in pieces 2/3 and 1/3 through if possible. There are also yeast strains that are more forgiving or are claimed to not produce it at all.

Renaissance Yeast markets yeast specifically cloned and engineered not to produce H2S. "Patented H2S-preventing technology that is the result of a natural trait in yeast that increases sulfur and nitrogen utilization efficiency during fermentation, thereby preventing hydrogen sulfide formation."

 

[CDrew]

Renaissance Yeast markets yeast specifically cloned and engineered not to produce H2S. "Patented H2S-preventing technology that is the result of a natural trait in yeast that increases sulfur and nitrogen utilization efficiency during fermentation, thereby preventing hydrogen sulfide formation."

This is the ultimate prevention. My 2 year experience with Avante has been great, and I've converted all my wine making friends. Next year, I'm also trying Bravo at the end of the season when it's cooler. But I have now significant experience with Avante yeast, and can tell you it's great for most home wine making fermentation. It's quick and clean and incapable of making H2S. Many other favorable attributes too.

With any cultured wine yeast, you can hope to prevent H2S with a good nutrient protocol. And it works, mostly. But for absolute certainty, the Renaissance yeasts are the thing.

 

[user 36973]

That is, the copper is all on the outside, where the wine can get at it. As far as the wine is concerned, the penny is 100% copper

So it is even worse then. Regardless, this is exactly what the problem is that we are trying to avoid.

 

[DAB]

Okay, lesson certainly learned. Thanks for the gouge. Henceforth, I will come at this problem from a different angle. First with Reduless in the short term and then with Avante yeast in the long term.

Thanks again guys, I'm learning much for all of you!

 

[DAB]

Okay, added the Reduless and let sit for 4 days, then re-racked. The smell, however, is still there. Now, it's time for some incremental copper sulfate additions.

 

[Johnd]

Okay, added the Reduless and let sit for 4 days, then re-racked. The smell, however, is still there. Now, it's time for some incremental copper sulfate additions.

Aren’t you supposed to dose a second time if the first doesn’t completely remove the smell? I’d do that before moving to a different product.

 

[stickman]

I agree with above that Reduless does indicate the possibility of needing a second dose. If you do decide to go the copper sulfate route, bench trials are recommended and most suppliers have instructions available to help. The following instructions are from a commercial lab kit which details how the trials are conducted, and also provides good background information on the subject.

 

[DAB]

Well, I did not know that--the package I received from Morewine.com doesn't speak to the number of doses so I incorrectly thought it was a one-and-done. That said, I dosed it again this evening. Fingers crossed this second dose will, once and for all, eliminate these pesky odors.

I do continue to learn much from all of you. Many thanks!