stuck fermentation -help

[JohnBurns]

I've got seven 5 gallon carboys of a Bordeaux blend that seems to have stopped fermenting at 1.010. I pressed and racked the grapes at 1.022 on 10/10. On 10/13 they were at 1.014 and the last 2 days now at 1.010. I can taste the sweetness still. Should I add a little nutrient to each carboy? Yeast? Appreciate this forum and the feedback. Thanks

 

[CDrew]

A bit more info would help. What yeast was used and what was your nutrient protocol?

But generally some nutrients may help, a good stir might help, but most likely warming it up to 75-80F would be the biggest help. If none of that helps, it can be a bit of a chore to get things to restart, so good luck.

 

[Jim Welch]

Also, what was the OG? What is the must temp? In my experience it’s not unusual for fermentation to slow way down at that point. Also, from my readings yeast do not reproduce after 10% ABV and do not really require nutrients unless reproducing so what I do or rather not do is add nutrient once the must approaches or exceeds 10% ABV. Not sure if you’re there yet without knowing the OG.
Maybe give each one a gentle stir to kick any settled yeast up and take care it doesn’t cool down too much.

 

[JohnBurns]

Thanks. I'll give each a general stir. Also, starting OG was 1.102. Fermentation was at 74F RT and the must heated up as high as 79F. I used 8 gr D254 yeast hydrated with Go Ferm and then mixed with 1 cup warm water and 2 cups of must. I did this a total of 3 times because I started with 50 gallons. I punched the cap 4x/day. I added 50gr Fermaid K day 3 and 6 and pressed on day 10.

 

[CDrew]

Thanks. I'll give each a general stir. Also, starting OG was 1.102. Fermentation was at 74F RT and the must heated up as high as 79F. I used 8 gr D254 yeast hydrated with Go Ferm and then mixed with 1 cup warm water and 2 cups of must. I did this a total of 3 times because I started with 50 gallons. I punched the cap 4x/day. I added 50gr Fermaid K day 3 and 6 and pressed on day 10.

While it likely does not matter, it was a bit underdosed with yeast at the start. The MoreWine manual recommends 1-1.5 gm per gallon. Though after a few days, there would be plenty of yeast in the colony to execute fermentation. Your nutrient addition also looks pretty sound. If you wish to add more nutrient, I might consider a half dose of Fermaid O. If you cant get it to restart with simple measures, it will be time to try another yeast that tolerates high alcohol levels. But some added warmth may be all it really needs to get to dry. Best of luck.

 

[JohnBurns]

Thanks a gentile stir and warming the room will be my plan.

 

[JohnBurns]

Stirring and a warm room brought the SG down to 1.004-1.002 across the 7 carboys. They have been stuck there for 2 days. I'm thinking of a half or quarter dose of Fermaid K, or maybe yeast energizer or Fermaid O? Also, an option to add a little yeast Ec1118? Thoughts appreciated.

 

[Jim Welch]

I’d say no to more nutrients or energizer and yes to the 1118. The problem with nutrients at this point is if they are not fully utilized by yeast they remain as good for other microorganisms. Before this I’d give it more time though, the SG will likely continue to drop.

 

[winemaker81]

Do you have grapes in a carboy, or is this juice at this point?

Being in a carboy with limited O2 slows generation down. Give the wines a stir and another couple of days

 

[Rocky]

What is the temperature of the wine? I have found in such cases it helps to give the yeast a boost by warming some wine to about 80 degrees F and then adding the yeast (EC1118 is a good choice). Pour about a cup of this mixture into each carboy and stir well. In your case, with 7 carboys, you would need to warm about a half gallon. If you do this, warm it very carefully and do not go above 80 degrees F.

 

[Jim Welch]

@JohnBurns One other thought here, what are you using to measure SG, a hydrometer? If so, have you “calibrated” it by measuring the SG of distilled water? Many hydrometers are a couple points off.

 

[Hazelemere]

EC1118 inhibits malolactic fermentation if you want that. Take the yeast you started with, add it to apple juice with nutrient. Once it starts fermenting slowly bleed the red wine into it but not all in one day. e.g. 1/2 gallon day 1, 1 gallon day 2, what is left day 3. If you fermented it in a carboy it stopped because the yeast were looking for oxygen. If it stopped in a pail, the yeast were looking for nutrient IMHO.

 

[Jim Welch]

From the OP it seems the 35 gallon batch was under pitched, the starter helped a lot it would seem. IMO, the yeast colony is just tuckered out. I’d keep it warm ish and wait some more. 1,022 on the 10th and _1.003 ish now? They’re still alive, some of them.

 

[winemaker81]

From the OP it seems the 35 gallon batch was under pitched, the starter helped a lot it would seem. IMO, the yeast colony is just tuckered out. I’d keep it warm ish and wait some more. 1,022 on the 10th and _1.003 ish now? They’re still alive, some of them.

I agree that the wine was under-pitched. A general rule is 1 g yeast per 1 US gallon / 4 liters, although specific strains may indicate more or less yeast. Based upon the OP's comments, about 2/3 of the "proper" amount was used.

However, a smaller initial colony means the yeast has an upward battle to build critical mass, but eventually commercial yeast should win out. This starts with a less than ideal situation, but it appears that it worked out. This explains what appears to be a long fermentation.

D254 is ABV tolerant to 16%, and the must is roughly at 13.6%, so that doesn't appear to be a problem. Adding EC-1118 may not make any difference.

@JohnBurns, what was the SG when you pressed? I missed that you pressed on day 10 during my last read? The timeline is not clear.

Patience, Grasshopper. The wine is under airlock, give it another week, then check SG.

I've had at least one wine stop at 1.000 and not finish for 3 months, and no, I have no idea why. I've had a few stick around 1.002 and never budge, but most ferment out when given time.

 

[Jim Welch]

“2/3 of the proper amount”?
He started with 50 gallons of must, I’d say the under pitch is closer to 6.7% that 67% but that’s water under the bridge. Good thing a starter was used.

 

[winemaker81]

“2/3 of the proper amount”?
He started with 50 gallons of must, I’d say the under pitch is closer to 6.7% that 67% but that’s water under the bridge. Good thing a starter was used.

re-read the OP's post. he used 8 g ... 3 times. 24 g

I missed it the first 2 times.

 

[Jim Welch]

I missed some details my first reading, saw the 7 5 gallon carboys, so 35 gallons of wine, but didn’t notice that started as 50 gallons of must until my third reading!
Goes to show the capabilities of yeast, that’s not much yeast even with the modest starter to ferment that to this point. I think they’ll keep chugging along.
But I would reiterate about checking the hydrometer, a couple points at 1.102 is nothing but below 1.000 it’s more significant.

 

[winemaker81]

But I would reiterate about checking the hydrometer, a couple points at 1.102 is nothing but below 1.000 it’s more significant.

I disagree. Because of hydrometers not being correctly calibrated, differences due to temperature, human error in reading measurements, and differences in the wine itself, a few points on the hydrometer are not a concern. I have records of 110 batches that includes fruits, red grape, red juice, white juice, kits, and "other". The final SG ranges are:

Final SG​	Percent​
0.990 - 0.994​	37%​
0.995 - 0.998​	47%​
0.999 - 1.002​	10%​
1.003 - 1.015​	6%​

Generally speaking the lower FG was lighter wines and/or higher ABV wine, while the higher FG was heavy reds, and the highest were "other" wines, which include a mead and some commercial drinking juices. But there were oddities, including a heavy red with a low FG and a few whites with a high FG.

Specific Gravity is the relative density of a liquid with respect to distilled water. This includes the water, alcohol, sugar, and other substances in the wine. I realize I'll never know the exact answer, so I look at the SG, the situation of the wine, and simply take some things on faith that I'm ok.

With a few exceptions, such as H2S, patience is our friend.

 

[CDrew]

It is possible the wine is actually done. If you have the usual inexpensive broad scale hydrometer, it may have enough inaccuracy to mislead you. As someone else said, try calibrating it with distilled water at the same temperature as your wine.

Then for next wine making season, get a hydrometer that reads plus or minus 5 brix. Then you know very accurately what your finishing brix and specific gravity is and can make decisions based on a reliable number. I think in your case right now, you risk doing more harm than good by adding more yeast. I would add malo-lactic bacteria to get that fermentation underway.

 

[JohnBurns]

I agree that the wine was under-pitched. A general rule is 1 g yeast per 1 US gallon / 4 liters, although specific strains may indicate more or less yeast. Based upon the OP's comments, about 2/3 of the "proper" amount was used.

However, a smaller initial colony means the yeast has an upward battle to build critical mass, but eventually commercial yeast should win out. This starts with a less than ideal situation, but it appears that it worked out. This explains what appears to be a long fermentation.

D254 is ABV tolerant to 16%, and the must is roughly at 13.6%, so that doesn't appear to be a problem. Adding EC-1118 may not make any difference.

@JohnBurns, what was the SG when you pressed? I missed that you pressed on day 10 during my last read? The timeline is not clear.

Patience, Grasshopper. The wine is under airlock, give it another week, then check SG.

I've had at least one wine stop at 1.000 and not finish for 3 months, and no, I have no idea why. I've had a few stick around 1.002 and never budge, but most ferment out when given time.

Yes I pressed on day 10 when the SG was 1.022. Thanks for the feedback. Trying to be patient