Hydrogen sulphide - major frustration- what am I doing wrong

Winemaking Talk - Winemaking Forum

Help Support Winemaking Talk - Winemaking Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Rocktop

Senior Member
Supporting Member
Joined
Sep 5, 2019
Messages
136
Reaction score
128
Ok so my fall so far, 300lbs Pinot noir , pulled off 5 gallons of juice for rose, put half of those skins back on the remainder.
Fermented red with bm 4x4 used Ferm aid o at hydration, added suggested fermk amount at 1/3 Brix drop, got sulphur smell during ferment, added more Ferm k punched down more - seemed to help but now major hydrogen sulphide smell in carboys .. splashed racked and reduless on its way, questionable if I can save.

Rose fermented with icv-gre - carboyed almost immediately , slight but noticeable hydrogen sulphide smell.

Fast forward several weeks, crushed 100 lbs merlot, fermented lower temp and used Ferm aid o when hydrating yeast as above, added fermk at 1/3 Brix drop. Pressed, racked and ... come on.. hydrogen sulphide, rotten eggs smell again!

Pushing $600 of grapes wasted...

My question is, what is your nutrient addition amounts, and exact addition time?
Also is it possible sulphur sprays too close to harvest a potential source?

Super frustrated and somewhat defeated..
RT
 
Where did you get the grapes? It sounds like you are following a good nutrient schedule so it could possibly be sulfur spray too close to harvest.

From the Vintner Vault:
Hydrogen sulfide gas is often produced from elemental sulfur during primary fermentation. Grapes are often treated with sulfur sprays to control powdery mildew, and the residual sulfur on the grapes is transferred into the juice. The sulfur is then converted into hydrogen sulfide by the reducing atmosphere of fermentation. To avoid this problem, most grape growers stop spraying with sulfur several weeks before harvest time.
Their summary:
Hydrogen sulfide gas produces a rotten egg smell in wine, and very small quantities make a wine undrinkable. Hydrogen sulfide production can be minimized by avoiding grapes containing excess sulfur, by adding extra yeast nutrients, by avoiding Montrachet yeast and by racking new wine promptly. Racking with aeration may be successful in mild cases of hydrogen sulfide, but carefully adding small quantities of copper sulfate is the preferred treatment.

Full article. Wine Making Tips - The Vintner Vault - The Vintner Vault

I'm not sure how to avoid excess sulfur on grapes other than to know your vineyard...or (GASP) wash the grapes. Sorry you are having so much trouble. Could you smell any sulfur when crushing or see residue on the grapes?
 
Without knowing the YAN of your grapes, you cant know if the nutrient schedule was appropriate, do you know the YAN? It is also quite possible, as stated above, that it could be due to spraying too recently.

My nutrient protocol on grapes of unknown YAN is more robust than yours, I’m not saying it’s right on track, but it’s never let me down, even with RC212 as one of my yeasts. Start off with a full dose of DAP, followed by a 1/2 dose of Fermaid K at 1/3 & 2/3 sugar depletion. I only use the Fermaid O when I need a nutrient boost below 1.030. GoFerm is the product for use at rehydration, though it probably makes no difference. Best bet, get your YAN, then craft your protocol. If not, have DAP on hand, it’ll knock out H2S production in minutes, it’s gotten a bad rap in recent years, I believe it to be a great part of my nutrient options, applied correctly.
 
I do almost exactly the same as John above me suggests. I assume I have low YAN, since I never know what it is and act accordingly. Full dose of DAP (maybe even a 120% dose), 1/2 Dose of Fermaid K at 1/3 and 2/3 sugar depletion and Fermaid O, only if some issues develop late, which they haven't in the past 4 years following this procedure. I know that the hybrid grapes I will be dealing with from Missouri will always have somewhat higher Potassium measurements and can handle a bit extra nutrition.
 
The problem may be in your rehydration. Go-Ferm is recommended for rehydration, not Fermaid-O.

"Go-Ferm is the original natural yeast rehydration nutrient containing a balance of micronutrients... Do not use nutrients containing ammonia salts, such as DAP, during yeast rehydration - they are toxic to the yeast at high levels." [GoFerm | Scott Laboratories]

"Fermaid O does not contain any DAP or supplemented micro-nutrients. For optimal results, Fermaid O should be used in conjunction with Go-Ferm Protect Evolution rehydration nutrient." [Fermaid O | Scott Laboratories]

Maybe your yeast aren't getting the needed micronutrients provided by Go-Ferm. Some web sites say Fermaid-O has no *added* ammonia salts. Does it have some? I'm not sure if this is your problem, but I would try rehydrating with Go-Ferm instead of Fermaid-O.
 
Oops sorry all, meant goferm at hydration, I don’t have Ferm aid o, just Ferm aid k.
Is DAP just standard yeast nutrients you see in all brew shops?

Thanks all.

Ps does anyone wash their grapes? In the merlot especially I noted a slight sulphur smell at picking. I get my grapes from a vineyard that sells to many big guys. Next time I will ask specifically when was last spray...
 
I know of a commercial winery that did wash grapes when they arrived with a sulfur smell. The workers had started to crush before the winemaker arrived. He made them stop crushing immediately and washed the remaining grapes. He fermented the already crushed grapes but was never able to get rid of the sulfur. He wrote every winemaker he knew and no one could help. They had to dump the unwashed batch.

So it has been done to save the wine before crush.
 
MoreWineMaking.com recommends the following nutrient additions.

“Fermaid-O Addition (1st dose): At first formation of a cap, use 1.5 grams of Fermaid-O per gallon of must.”

“Fermaid-K Addition (2nd dose): A third of the way through fermentation (after 8–10° Brix have been consumed), use 1 gram of Fermaid-K per gallon of must.”

[https://morewinemaking.com/web_files/morebeer.com/files/Red_Winemaking_Outline-2014.pdf]

I used to use a half-dose at each addition, but I sometimes got off-smells. I have had no problems since I changed to a full-dose. From your post, it looks like you skipped nutrients at the first cap.
 
Oops sorry all, meant goferm at hydration, I don’t have Ferm aid o, just Ferm aid k.
Is DAP just standard yeast nutrients you see in all brew shops?

Thanks all.

Ps does anyone wash their grapes? In the merlot especially I noted a slight sulphur smell at picking. I get my grapes from a vineyard that sells to many big guys. Next time I will ask specifically when was last spray...
If you can smell sulphur on the grapes at harvest, there is a problem. They are either spraying too much, too frequently or too close to harvest. I help manage 20 acres of vineyards and we stop spraying a month or more before harvest.
 
He fermented the already crushed grapes but was never able to get rid of the sulfur. He wrote every winemaker he knew and no one could help. They had to dump the unwashed batch.

So the winemaker wasn't satisfied that copper sulfate treatment would sufficiently remedy the issue?

They are either spraying too much, too frequently or too close to harvest. I help manage 20 acres of vineyards and we stop spraying a month or more before harvest.

I pulled a label for sulfur dust and it allows it to be used up to the day of harvest. While that may be legal, it sounds like it isn't best practice.
 
Pushing $600 of grapes wasted...
You can remove the hydrogen sulfide by treating the wine with copper sulfate. Here, for example. While it is definitely better to prevent a problem in the first place if possible, you can solve this one after the fact. Perhaps washing the grapes will remove enough of the sulfur dust, if that is causing the problem.
Start off with a full dose of DAP, followed by a 1/2 dose of Fermaid K at 1/3 & 2/3 sugar depletion
The op may benefit from what you mean by "full dose". Do you target a ppm addition or a measured addition by pound of grapes? This way he can compare what he added by what you add.
. Full dose of DAP (maybe even a 120% dose), 1/2 Dose of Fermaid K at 1/3 and 2/3 sugar depletion and Fermaid O
The op may benefit from what you mean by "full dose". Do you target a ppm addition or a measured addition by pound of grapes? This way he can compare what he added by what you add.
 
Wow, 5 weeks before picking, I had no idea it was that long before picking to fully dissipate.
Great info to have on hand for the future.

For the current batches I have reduless and 1% copper sulphate coming in the mail today. I will try the reduless first and see if I can salvage. I am less apt to use the copper sulphate based on many warnings .

For my soon to crush cab sav & petit Verdot batches- I don’t have ferm o and hand. Can I get away with Goferm at yeast hydration and then 2 additions of fermk, once at cap form and once at 1/3 brix drop? If ok, should I dose at 1.5 grams at cap form and the 1 gram per gallon at 1/3 brix drop?

Last question, have others switched over to the yeast strains that are designed to reduce hydrogen sulphide production, ie Renaissance ?

Thank you all for your help. After years of wine making from juice I was so excited this year to really dig into the craft of full scale wine making but certainly got some early learning lessons.

RT
 
Below is the disclaimer by Renaissance regarding potential H2S even when using their "No H2S" yeast.

"Note: Regardless of the yeast used in fermentation, elemental sulfur introduced from vineyard sprays and present on grapes at harvest time, as well as contamination by other commercial or wild yeast, can result in sulfide by-products forming in the wine. Therefore, to eliminate H2S contamination altogether, it is necessary to carefully avoid the introduction of sulfide-containing chemical sprays, as well as co-inoculation by other yeast strains that may be present in the vineyard or resident inside the winery equipment. "
 
Last question, have others switched over to the yeast strains that are designed to reduce hydrogen sulphide production, ie Renaissance ?

Yes, and they are excellent. Extremely clean fermentations. I've been using nearly all Avante for 3 years now and have perhaps 10 or so fermentations with Avante complete. Next year I'm expanding to whites and so will try more of them. I just don't see a downside. Avante is amazing with fermentations finishing in 4-5 days-I would like to pursue temperature control to extend out to a week! The press I did this Friday was pitched the Sunday night before, so complete in 4 days.
 
Yes, and they are excellent. Extremely clean fermentations. I've been using nearly all Avante for 3 years now and have perhaps 10 or so fermentations with Avante complete. Next year I'm expanding to whites and so will try more of them. I just don't see a downside. Avante is amazing with fermentations finishing in 4-5 days-I would like to pursue temperature control to extend out to a week! The press I did this Friday was pitched the Sunday night before, so complete in 4 days.

The new non-h2s forming cultures really are awesome. It’s pretty remarkable to have such clean smelling wine post pressing. Every time I use something other than Avante yeast I will catch some hints of h2s after pressing. (I believe my avante use helped me to better detect even super slight hints of h2s when comparing)
A good rough racking off the gross lees usually takes care of it. But still have had some residual h2s lingering. Typically tho the racking aftermlf completion removes it. Have yet to have a bad bout that wasn’t able to be removed with the scheduled rackings. Always splash racked. And small jugs just dumped with funnels.

and @CDrew there’s another Non-h2s Renaissance culture for big reds I wanna try out called Muse. Similar tolerances and a little slower moving.

@Rocktop if you’ve got any copper pipe around try using a small piece to stir a glass. See how much stirring it takes to remove the smell. Should help in knowing how easy or difficult (or if even able) this will be to remove.
 
Last edited:
For my soon to crush cab sav & petit Verdot batches- I don’t have ferm o and hand. Can I get away with Goferm at yeast hydration and then 2 additions of fermk, once at cap form and once at 1/3 brix drop? If ok, should I dose at 1.5 grams at cap form and the 1 gram per gallon at 1/3 brix drop?

You do not need to use Fermaid-O. Two doses of Fermaid-K is fine. That’s what I did this year and last. I don’t use Avante. I had no H2S issues.

*Rehydrate with Go-Ferm.
*Add 1 gram of Fermaid-K per gallon of must at first cap.
*Add 1 gram of Fermaid-K per gallon of must at 1/3 Brix depletion.
 
Thank you Blue! That is what I will do.

Just got word 400lbs of Cab Sav and 100 lbs petit verdot is ready for picking tomorrow.
I will put the new nutrition plan into action and let you all know how it goes.

RT
 
The op may benefit from what you mean by "full dose". Do you target a ppm addition or a measured addition by pound of grapes? This way he can compare what he added by what you add.
“Full dose” in my book is determined as an addition of DAP in weight (typically grams) per unit of volume (typically gallons) of finished wine. That’s the way nutrient additions are typically defined. It’s important to note that finished volume of wine is somewhat less than volume of must if you are making wine from grapes, finished volume is 65% - 70% of the must volume.
 
Ok, long day done.
Drove and picked up 400 lbs cab sav and 100lbs Petit Verdot.
Cab Sav was 25 brix and 3.52 pH
PD was 24.5 brix and 3.19 pH
Last sulphur treatment was august 26th.
If there is any hydrogen sulfide smells this time it is on me. I will implement the nutrient regiments as above and hope for better results.

Thank you all.
RT
 

Latest posts

Back
Top