Ferment stalled

[beisang]

I could use some advice on next steps.
I have been making a wine expert Pinot noir the initial fermentation has stalled at a S.G. Of 1.035
It has not moved for 15 days. My local store suggested I rack the wine and patiently wait.
Result- no change in Specific gravity.
Do I add yeast and nutrients and give it more time.
I have nothing to loose except 30 potential bottles of wine. Thanks for your collective wisdom



I am asking for

 

[botigol]

Yeah, you have the right idea. I would only add that you should make a starter for the yeast since the alcohol that was previously produced will have some inhibitive effect beyond whatever led to the stall. Basically, follow the instructions on the yeast packet for rehydrating, then add a teaspoon of sugar, wait for 5-10 minutes, add 1/4 cup of your wine. Once it starts to foam, dump it into the wine.

 

[beisang]

Thanks for the advice.

Is there any advantage to adding some sort of yeast nutrients (besides the sugar ) to the starter?

 

[BernardSmith]

I am not sure about whether the advantages of adding more nutrient to the starter outweigh any risks (although I suspect they don't). But I would adopt a different tack from the one recommended by Botigol. I would keep on doubling the quantity of wine I add to the starter rather than add the starter to the wine. In other words, if you can, I would dump the starter in a bucket and once the starter has begun to show signs of yeast activity I would add 1/4 C of the wine to that starter. After an hour or so I would then double the quantity from the stalled wine so now the starter has 1/2 C and then after a few hours add another 1/2 C (so now it is 1 C ) then add 1 C (for a total of 2 C) then when that is showing signs of good activity add 2 C and so on until you have about a gallon of active wine. Then I would add that gallon to the stalled must. The process takes about a day or more but what you are doing is ensuring that you have a good colony of active yeast. And by adding the stalled wine to the starter, hopefully, any problems in the must are being neutralized by the fresh starter until there is a large enough "starter" to dominate the moribund yeast in the must...

 

[botigol]

Good call Bernard. My way would be more convenient, but yours would remove any issue of failing to restart.

Nutrients may or may not be necessary, but they can't hurt. Sugar is usually used, because yeast ferment it easily, so it kick-starts the process. Now that I really think about it, nutrients would provide better result if added to the bulk of the wine prior to adding the starter. The starter itself shouldn't need extra nutrient, but adding nutrient to the rest of the wine will help ensure that the new fermentation keeps going.

 

[JohnT]

Another thing to watch is the temerature of your must. Try to bring it up to at least 65 degrees.

 

[robie]

I agree with JonhT, except in this case, I would go for even higher, since it has completely stalled. Get it up to 72 to 75F. Give the must a really good stir from bottom to top just before you add the yeast starter. Make sure the temperature of the starter is within a couple degrees of the must.

You haven't added any of your other packets, yet, have you?

 

[beisang]

Thank you all for the advice. I have not added any growth inhibitors so I have hope that I can still save this batch.

I will take the combination of suggestions by adding nutrient to the whole carboy then starting yeast culture in a separate container and adding must until I have successful fermentation in approx. 4 liters, then add it back and pray.
2 questions What is the best yeast nutrient to use ,and what is the best prayer to use?
Thanks

 

[botigol]

Fermaid-K is a good one. Just straight DAP (diammonium phosphate) would probably do the job as well. In a pinch, you could pitch an extra packet (in addition to the one in your starter) of yeast into 1/4 cup of hot water (hot enough to kill the yeast) and once cooled, use that as nutrient. I was going to jokingly suggest "Ode to Bacchus" as the prayer. Luckily I decided to google it, because as it turns out it is a real poem...its a bit long and mostly off point, so probably not the best choice.

 

[abefroman]

After 15 days, personally I would just stabalize it and have a semi-sweet wine.

 

[Norske]

I pulled this from one of the stores I buy things from.

"Yeast Hulls are ususally the first action when you have a stuck or sluggish alcoholic or malolactic fermentation. Yeast Hulls are essentially dead yeast cells that absorb auto toxic yeast by-products that could be inhibiting your active yeast or ML culture from doing their job - finishing your fermentation! Yeast Hulls are then typically followed by Pro-Desert in the case of a stuck alcoholic fermentation or Acti Ml in the case of a stuck ML ferment.

As a side note, Yeast Hulls are included in the Fermaid K mix of nutrients to help prevent problem ferments from the onset. The reason you would not use Fermaid K for most stuck ferments is that Fermaid K contains DAP. If DAP (Diammonium Phosphate) is added to the ferment past the point of metabolization by the yeast it could potentially leave an unwanted, residual flavor. Use at the rate of .5 to .9 grams per gallon."