Sulfer smell and fast fermentation

[Arkansan07]

I started 15gal of blackberry last week and pitched my yeast (Montrachet) on friday. It violently fermented for 2 days. I checked it today and the SG was already at 1.00 after starting at 1.09. I went ahead and pressed the fruit out and racked it. It seems to have a sulfery smell, could this be from the very fast fermentation? I took a sample and chilled it in the fridge and the smell was much less from the chilled sample. Im hoping that the smell goes away after its done. Thoughts? It is fermenting so hard I had to tape down the bungs, even with airlocks the CO2 was pushing them out.

 

[Arkansan07]

Anyone have any advice? I been searching and people have mentioned splashing and using copper

 

[Boatboy24]

Standard practice with grapes is to rack again a couple days after pressing. That may be helpful in your case as well. You'll get the wine off the gross lees and get a little air in there to blow that smell off.

 

[ceeaton]

I'd wait till fermentation is totally done and you rack off the gross lees and take a sniffy-sniff. Of all the wines I made my blackberry from this summer had a few more "interesting" aromatics while it was fermenting. It tastes and smells fine now 6 months later.

I don't have enough experience to tell you whether it was from the blackberries or a product of the yeast fermenting that fast. Hopefully others with more experience will chime in on the subject.

 

[Arkansan07]

Ok thanks guys, as hard as it is fermenting I dont think it will take long.

 

[JohnT]

Montrachet is vulnerable to yeast breakdown. You make no mention of yeast nutrient. If fermentation is still in progress, I would add a shot of nutrient to halt the production of H2S.

Once fermentation ends, and the thick layer of sediment forms, splash/rack your wine.

If you still have H2S issues, then try using a product called Redueless. This is dead yeast impregnated with a measurable amount of copper and works wonders.

I would also suggest you look into changing the yeast you use. I am not a fan of montrachet.

 

[Arkansan07]

I used nutrient and energizer at the specified doses on the package. I read alot of people are fans of that71B yeast that metabolizes malic acid for blackberry. My family has a berry farm and all our berries are bred for low acid and I pick them super ripe so acid is lower. Made some a few years ago with montrachet and it was great.

 

[Turock]

Montrachet produces quite a bit of H2S when its stressed so it's very important to use a good nutrient protocol with this culture. Meaning that you need to calculate the entire nutrient dose, then divide it in half. Half of it goes in to the vat when the yeast becomes active, and the second dose when you get to 50% sugar reduction. Infact, you should do this with ALL cultures.

H2S does not go away, and even if the smell is gone, you are never sure if some of it still is not lingering in the final product that CAN cause issues down the road. Reduless is the treatment of choice as it only puts a nominal dose of copper into the wine. H2S must always be dealt with when you first find it or else you risk forming mercaptans which are even harder to get rid of.

Montrachet is a great culture for fruit--we use it often. Just be sure to use good nutrient management and you will have no problems. We've used it for 26 years and have never had a H2S issue. However, we use 71B on blackberry in order to metabolize a portion of the malic acid. It makes a smoother result, as malic is such a harsh acid. But I see your berries are low on acid--and you used Montrachet successfully in the past. Stick with the Montrachet--just change the way you use nutrient.

 

[JohnT]

+1 on what Turock said... You could even split into 3 doses.. 1 prior to pitching yeast, 1 when 40% fermented, and 1 when 90% fermented.

 

[Turock]

Well, you've got to be careful about adding TOO much DAP(regular yeast nutrient) in the beginning of the ferment because you COULD encourage any wild yeast to take off on you. This is why instructions on nutrient usually say to add the first part of the dose once your pitched culture of choice takes off. If you're going to add anything prior to the ferment, the choice would be Fermaid O, which can be used 24 hrs. before pitching the culture, as it adds a nice quantity of nitrogen.

Using more nutrient after 50% sugar reduction is not a good choice, as it can encourage any bacteria growth, and the yeast can't utilize the nitrogen very well after that point.

 

[JohnT]

I normally add a dose of k-meta 24 hours to pitching to stun the wild yeast.

 

[Turock]

Yes but-----give them enough nutrient and they COULD take off on you. Pitching the known culture and having it dominate puts any wild yeast so far behind in competition that they THEN are not an issue. You can't depend completely on the wild yeast being stunned enough to not take off as there could be more aggressive yeast there than you truly know.

 

[JohnT]

Yes but-----give them enough nutrient and they COULD take off on you. Pitching the known culture and having it dominate puts any wild yeast so far behind in competition that they THEN are not an issue. You can't depend completely on the wild yeast being stunned enough to not take off as there could be more aggressive yeast there than you truly know.

I mainly do this to give the nutrient a chance to dissolve thoroughly throughout the must (600 liter tubs and I macerate my reds) by the time my yeast comes active. I prefer to give the yeast some nutrient as early as possible to eliminate even the smallest risk of stress..

I adopted this 3 dose treatment 10 years ago and have not been visited by that evil H2S or have had any unexpected off flavors due to wild yeast. I simply can not complain about the results.

I know that this is not the method that you prefer to use, so we will have to agree to disagree.

 

[Turock]

It's not about disagreement. It's about being sure we are clear on procedures, due to the many new winemakers on this site that may get confused. It's always best to teach best practices so they don't run into problems. YOU may be able to make this protocol work, but many others may not.

 

[JohnT]

Some reading.

http://www.grapestompers.com/articles/yeast_nutrients.htm

http://shop.abccorkusa.com/abc-pdfs/faq/Nutrients and Wine Yeast.pdf

 

[Turock]

I see what you're talking about there John, and to be honest I can't see why anyone would encourage a winemaker to make a nutrient addition before pitching the culture. You can get any biologic, that wasn't knocked down by the SO2, to take advantage of the nutrient. This is why they came up with Go-Ferm Protect. So that you can set up your must with micronutrients,etc before pitching the yeast without being afraid of feeding wild yeast or biologics because it binds up certain nutrients that the yeast can't use. Now I'm in favor of that protocol.

SO2 is mostly for biologic control--not really stunning the wild yeast. The only reason you don't get a wild yeast ferment is because you're over-dominating the wild yeast with your big packet of known yeast. To use DAP before you get your known culture dominating the must, COULD get a wild ferment going. I just can't see the logic of pitching nutrients ahead of the culture---but DO see potential problems with that protocol. Unless you use a product like the Go-Ferm Protect.

 

[ibglowin]

That is a totally false statement. Wild yeast are much more susceptible to Sulfites, that is why you add it at crush. Cultured yeast has a higher tolerance of Sulfites. Knock down the weak and let the strong take over.

SO2 is mostly for biologic control--not really stunning the wild yeast.

 

[Turock]

That is simply not the case. SO2 is used for biological control. Your known culture dominates the wild yeast.

You may knock down SOME of the wild yeasts, but that is not the true intent of SO2. It's an antioxidant and antimicrobial, above all.

 

[ibglowin]

Sigh………

"When added at the pre-fermentation stage, it (SO2) inhibits the action of all yeasts; wine yeasts are just more resistant than other microorganisms. So, at a target range of approximately 30-40 ppm, the naturally occurring yeasts will be inhibited while allowing the more resistant commercial strains to proliferate."

"Wild yeast and bacteria can consume sugar from grape juice just as easily as your special yeast can, but generally produce some pretty terrible flavors in the process. In addition, many wild yeasts are less tolerant to high alcohol levels, and may stop fermenting before all of the sugars have been consumed, creating a “stuck” fermentation. If this happens, left-over sugar could be used as a food supply for any spoilage organisms present, and the wine will be compromised. Therefore, sulfite is added immediately after you crush to “clean the slate” of these unwanted guests. The amount used is usually just enough to kill or at least inhibit spoilage organisms, but not enough to bother more sulfite-tolerant, cultured yeast strains that we recommend using."

Yes, SO2 is an antioxidant and does inhibit microorganisms but when added at crush its main job is to stun native yeast so that your cultured yeast can become dominant.

 

[4score]

Another correction - at least if you're using Fermaid K nutrient: Scott labs says to...

"Add 25 g/hL at 1/3 sugar depletion or in two doses; 12.5 g/hL at the end of lag phase and 12.5 g/hL at 1/3 sugar depletion."

Lag phase is when the cap has formed and fermentation has begun. Waiting until 50% completed is later than what is recommended by the manufacturer.