Hyrdogen sulfide.

[rwallick11785]

I am new here. Anyone got thoughts about preventing H2S. I am familiar with the usuals: Nurtients, temperature control, prompt racking off gross lees. I had problems last year with Michigan Chambourcin and H2S. I used lallemund MT yeast which isn't suspect like Montrachet and used Go ferm and ferm aid k dosing half the nutrient at the beginning of the fermentation and half after 1/3 sugar depletion. Am I missing something? I've got 300 lbs of Michigan Cabernet Franc coming and dont want a repeat.

 

[winemaker_3352]

Make sure you have the right about of nutrient and aerate the must - at least twice a day.

Get the O2 in there - yeast love it. If not it could struggle and cause the H2S..

 

[robie]

I agree with Jon, make sure you stir in lots of air for the O2.
How often did you stir during primary?
When in the cycle did you first notice the H2S?

 

[JohnT]

I also agree. For reds, I punchdown twice a day and really splash it up good. this is for the first week. I also split my neutriant dosage up into 3 applications. This way the yeast is fed throughout the primary fermentation process.

 

[rwallick11785]

I usually punch twice daily but have recently
Used heavy aeration with some fruit wine.

I initially noticed the problem with Chambourcin about 4 days into the 6 day fermentation and stirred hard and that helped. I noticed it again after racking off the gross lees post pressing although I left it on the gross lees for about 4 weeks (didn't know this was wrong at the time).

 

[MalvinaScordaad]

I am new here. Anyone got thoughts about preventing H2S. I am familiar with the usuals: Nurtients, temperature control, prompt racking off gross lees. I had problems last year with Michigan Chambourcin and H2S. I used lallemund MT yeast which isn't suspect like Montrachet and used Go ferm and ferm aid k dosing half the nutrient at the beginning of the fermentation and half after 1/3 sugar depletion. Am I missing something? I've got 300 lbs of Michigan Cabernet Franc coming and dont want a repeat.

You have followed a good procedure. However two things come to mind. You can never be sure of the YANC of the grapes unless you test them. Your typical additions of nitrogen inorganic or organic may not have been enough to make up for grapes with low YANC. So you need to look at your addition rates and consider increasing them. In addition you don't mention when you noticed the problem. If it was between 14 and 8 brix, even though it is better not to add any nutrient containing DAP below 10 brix, you could have added immediately a healthy dose of DAP. The second thing is late spraying. If the vineyard late sprayed and there was not sufficient time in the sun for the sulfur to dissipate prior to harvesting there is nothing you could have done to avoid the problem other than increased punch downs or pump overs and a quick racking off the gross lees 24 hours after pressing.
Malvina

 

[winemaker_3352]

What does YANC stand for??

 

[rwallick11785]

I also should say that I way over sulfited at crushing (like 120 ppm) it never occurred to me until reading all this that it could have been solely responsible for my trouble.

Any thoughts on a healthy crush dose of sulfite understanding that mlf is to follow after racking off gross lees post pressing?

 

[MalvinaScordaad]

What does YANC stand for??

http://www.ajevonline.org/content/49/2/125.abstract
Malvina

 

[MalvinaScordaad]

I also should say that I way over sulfited at crushing (like 120 ppm) it never occurred to me until reading all this that it could have been solely responsible for my trouble.

Any thoughts on a healthy crush dose of sulfite understanding that mlf is to follow after racking off gross lees post pressing?

I would keep it to 25 ppm with healthy fruit.
Malvina

 

[joea132]

I had a major problem with my 2011 Chilean carmenere that ended up with a garbage batch. This year I followed every precaution and still had a minor H2S issue. I quickly corrected it with reduless. Take precautions but it's equally important to know how to remedy the situation should it arise anyways. My issue with this year's carmenere was late spraying. It has been rectified and turned into a fantastic wine.

 

[andrewwon]

YANC Yet Another Newsletter Component
YANC Yet Another Nvidia Configurator (computing)