Concord grape wine - stuck fermentation

Hi. I posted back in 2015 about a concord grape stuck fermentation (Natural fermentation - stuck?), and I’ve got a similar problem again. This time, though, the starting gravity was a bit higher than I had wanted, because it was an excellent high-sugar grape year, and I didn’t take that into account when adding my sugar. So, I’ve got a starting gravity of 1.10 in October. In December it had dropped to 1.065, but it looked as if there was no further activity. So I extracted some juice and made a starter using Lavlin EC1118 champagne yeast. That seemed to work for a bit, and it’s now at about 1.030, but again, it looks like the fermentation has stopped. I tried making another starter, but even the starter didn’t kick off any activity. Fermentation temperature has been optimal. The juice definitely tastes good, although a bit sweeter than I like or had hoped, but I was hoping to drop the gravity more and increase the ABV a bit. Any thoughts? Thank you.

One of two issues… yeast is in poor shape or something causing yeast to stress out…
The fermenter… how do you take care of it? Pre must… Wash and clean with…?
Check the dates on the yeast packet… were they stored in the fridge? in a cabinet?
I really don’t think gravity is your issue with wine yeast…
Try shake your starter… giving it some oxygen… see if it starts again… Even give the starter a small pinch of nutrients…
Really crazy to have this happen again…
Sneezles61

Have you been feeding nutrient when you rack? How often do you rack?

What are you taking your gravity readings with?

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Hi. Thanks for the responses. I’ve racked only once, in December. I gave nutrient to my starter, but not to the wine itself. I generally use a refractometer to take my gravity readings (and use the Northern Brewer Refractometer Calculator to get a correct conversion. But I also checked with a regular hydrometer, and the readings were similar. As for the yeast itself, I don’t recall what the date was, but it was a recent purchase from Bell’s General Store. And as I said, I added nutrient. But I didn’t shake it to give it oxygen. What is strange I’ve got some white (niagara) and red, and the same thing happened to both, but the starter worked for the white; it’s again doing its business. Maybe I didn’t do my starter correctly. I prepared it according to the EC Kraus blog HERE (and shown below), but I just checked the Lalvin EC-1118 site HERE, and it says to use mostly water with a little juice after initial hydration, and everything should be done within 30 minutes. I’m going to try another starter per the Lalvin site. I’ll post back with results. Thank you all!

"For restarting 5 or 6 gallons, take a quart jar and fill it half way with the wine in question. Add to that, water until the jar is 2/3 full. Put in the mix a 1/4 teaspoon of yeast nutrient, and 3 tablespoons of sugar. Be sure that the sugar becomes completely dissolve. Now you can add a whole packet of the Champagne yeast. Cover the jar with a paper towel and secure with a rubber band.Buy Yeast Nutrient

Put the starter in a cozy spot at 70° to 75°F. You should see some activity within 12 to 18 hours. You will want to pitch the wine starter into the stuck fermentation right after you see the level of foaming in the jar peak. This will usually be around 1-1/2 to 2 days. Be sure to swirl the jar to add all the sediment in the starter to the wine must, as well."

Use dry yeast for wine. Sprinkle on top after a few days rack with nutrient into a carboy. After 1 month rack again with nutrient. Then rack with more nutrient at 3 months then age. If yo get more than 1/2"-3/4" crap on the bottom rack again. Wine is going to end at .009 or there about. So either your hydrometer is faulty or its not done. I would rack it with nutrient because wine juice doesn’t have enough nutrients.

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Wine is not like beer you get no benefit from a liquid yeast. There are tons of dry wine yeast to choose from but the difference is more to do with how dry or sweet you want to finish. I make alot of wine and i know alot of people and wineries and never use a liquid yeast. Nutrients and the oxygen from racking is key.

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It is dry yeast that I’m using (Lavlin EC-1118). I just rehydrated it per those instructions. I had initial activity from rehydrating the yeast, and at first it seemed like it was going to take, but I just looked again, and it looks like there is again no activity (in the concord wine). I’ll try more nutrient and another pack of dry yeast. Thank you!

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What are the temps where you are storing your vessel?

Storing at 68-70F.

I wonder if excess of CO2 (actually carbonic acid) is causing this issue. Try swirling the fermenter or stir, some use a wire whisk for this purpose. All sanitized of course.

Will do. I also picked up some more Lavlin EC-1118 yeast and will try a starting using mostly water and sugar with a little of the juice, as opposed to mostly juice with a little water. That did work and restarted the fermentation for my white. I’ll do that today and will post back how things are going. Thank you!

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