Hydrogen Sulfide Problem - End of Fermentation

[jerseyhomewine]

Hi Everyone,

I'm making wine from ~400lbs of fresh Long Island Merlot grapes (27gallons of must) and am currently 4 days into fermentation. The grapes started out low in Nitrogen and after feeding with Fermaid K and DAP, it turns out I didn't add enough because I am getting a pronounced hydrogen sulfide smell (no sulfites were added). The fermentation has been moving quick and is almost over (S.G.=1.018). Temperature is currently 88F.

Is there anything I can do to take care of this problem right now or do I have to wait until after fermentation is done? If I have to wait and/or the problem persists, what should I do during/after pressing to nip this in the butt and prevent the formation of mercaptans?

BTW I'm trying to do a malolactic fermentation after pressing so no sulfite additions until after MLF

Any input would be greatly appreciated
Thanks!!

 

[jamesngalveston]

was curious, is this a first batch of wine for you...
seems to me that you have stressed the yeast , if you used any, and if you didnt maybe there was not enough of the wild yeast present.

lots of grapes not to know how to handle a ferment problem.

 

[tingo]

How do you know they were low in nitrogen?

 

[Turock]

Now that the ferment is nearly done, you don't want to add anymore DAP. So use Reduless on it and some extra punchdowns of the cap. If you don't have any Reduless and have to order it--and the ferment is done and you have to press and move to the secondary--just go ahead and do that and then add the Reduless when you get it.

If you leave the H2S and don't fix it, then it can develop mono-mercaptans or poly-mercaptans. Fix this as soon as possible.

 

[jerseyhomewine]

This is my second batch of wine from grapes so I am new to the game (decided to go big). 5 packets of Red Star Pasteur Red yeast were used for the 27 gallons (fermenting in a 150L stainless steel tank).

The woman who sold me the grapes mentioned that they tend to be low in Nitrogen and told me to feed the yeast well.

Right now the fermentation is just about over (S.G.= 1.003) and I am ready to press.

Thanks Turock for suggesting using Reduless, I will be ordering some today

 

[Turock]

I just noticed you're going to MLF this wine. I'd use the Reduless first because you have to rack the wine off the Reduless in 72 hours. THEN do your MLF.

 

[jamesngalveston]

5 packets of red star pasteur red would need alot of nutrients, its a fast and nitrogen lover...and will raise the temp quickly if it doesnt have enough nutrient.
I read on a post about superferment, I belive it was turock that posted, any how when i use a yeast like pasteur red, are premier curvee, i always use superferment.

 

[Pumpkinman]

How pronounced is this odor? I would splash rack it before you add the Redulees (which is a great idea), try the small stuff before taking out the big guns.

 

[Turock]

I think that because you're going to MLF this wine, you need to be very cetain that you get the H2S off it beforehand otherwise the wine will be sitting a long time with the H2S on it while it's in MLF. That sets you up for mercaptans to form. You have no sulfites on this wine--I would not recommend splash racking.

 

[jerseyhomewine]

Thanks everyone for the replies! I really appreciate it.

So I placed an order online for Reduless and upon waiting for it to arrive I tried vigorously punching down the cap and stirring up the lees in primary. The H2S smell was strong but not out of control and after two sessions of this 10 hours apart, the H2S smell is just about gone now.

I pressed the wine yesterday and the H2S problem seems to have gone away completely (what a relief!). I will proceed with MLF tomorrow after racking off the gross lees, and keep the Reduless in case the smell decided to come back in the future.

One more question though:
The packet of Dry Enoferm Alpha Malolactic Bacteria (2.5g) I will be using is good for 66 gallons of wine and right now I only have ~ 20. Should I only use 1/3 of the 2.5grams or use the whole thing?

BTW I will also be using Opti Malo Plus malolactic fermentation nutrients to aid in the MLF because it will happen in the low 60 degrees F and I want to help the bacteria ferment in such a low temperature. Any thought on this? Are there any downside's to using Opti Malo Plus?

 

[Turock]

Add only enough bacteria for the amount of wine you have and absolutely use the Opti Malo!!!!

 

[Pumpkinman]

I'm glad to see that it worked out. You will have a great tool in your "war chest", experience, with possible stressed yeast. In essence, punching down more often introducing oxygen gave you the same effect that splash racking.
Not to mention that you'll have Redulees on hand if you ever need it.

 

[jerseyhomewine]

Thanks Turock and Pumpkinman!
I will use the Opti Malo nutrients and definitely am more knowledgeable about stressed yeast in Primary now.

Regarding the MLF, since I will be using the Opti Malo which contains cellulose to help keep the bacteria in suspension and being that I already introduced oxygen into the wine, how often should I stir the wine during MLF?

I've read that the fine lees need to be stirred back into suspension 2x/week but don't want to risk over-oxygenating the wine.

Also, the pH of the wine is currently at 3.45. How much do you think the pH will rise once MLF is complete based on your experiences?

 

[Turock]

All you need to do is stir the wine slowly. Rapid stirring will whip oxygen into the wine and you don't want to do that because oxygen is the enemy of an MLF. AND you have no sulfite cover, so just stir it gently. It doesn't take much stirring to get the MLB in contact with the wine. We stir our MLF's 2 times per week.

I'm not sure on the PH---you should take a PH reading when done so you know how much free sulfite you'll need.

 

[mgmarty]

my cab franc is going through malo in a glass carbouy. Should i be stiring it, and if so, how?

 

[Pumpkinman]

Stirring once or twice a week slowly is fine, but if you used Opti-Malo, you don't need to stir as the nutrients will be available to the MLB.

 

[Turock]

The stirring has more to do with keeping the MLB in contact with the wine. It shouldn't just sit on the bottom.

Wine supply stores have plastic spoons with very long handles. Using the handle to place down in the carboy as a big stir stick works great.