Is my yeast dead or stuck or just fine?

Question

I'm concerned my yeast be dead or stalled, and I'm sure some experienced person can give me some feedback.

This is my first batch of homemade wine. As my first batch, I wanted to do something very simple, so I followed this recipe, with a few small modifications, which uses frozen grape juice concentrate. Obviously, I don't expect world class wine out of this, but the reviews where largely positive.

After reading some comments on the recipe and other guides I did the following:

1. Dissolved my sugar in water and let cool to room temperature
2. Prepped my yeast with a bit of warm water and sugar for 20 minutes (using this yeast)
3. Put the sugar water, yeast, and 2 12 oz cans of grape juice concentrate into a 1 gallon carboy
4. I rubber banded a coffee filter over the carboy, and let it ferment for 6 days

Before I put the coffee filter on, I put a double bubble airlock on until the fermentation started (which took less than an hour and this was bubbling nicely). I've checked it every day for 6 days, and I could see bubbles rising up and foaming at the surface, so I know fermentation has been going well. Today it appeared to have slowed down, so I removed the coffee filter and siphoned the wine off the lees into a clean carboy. I added maybe a cup of water because I left a little behind when siphoning and I wanted to make sure I had a gallon. I put a double bubble airlock on, but so far it isn't bubbling at all. Now, I intend to let it do its secondary fermentation for 4 weeks.

Am I still on track (such as it is), or do you think my yeast is stalled or dead? I know the yeast isn't as active in secondary fermentation, but I expected some visible activity. If I'm off track, is there anything I can do to get back on? I'm not sure exactly what to expect at this point. Thank you for your help!

Answer 1

Probably should point out that activity like bubbles in the airlock doesn't always equate to active feremenation. In fact, it should be only be regarded as a suggestion that active fermentation may be happening. Depending on temperature, strain, available sugars and other factors, yeast can be working away and you may see very little bubbling in the airlock. Also, leaky fermenters can "lie" when using this as a metric too. The best way to tell if ferementation is happening is to pull a sample and check the gravity. If it hasn't changed in a few days, it's likely done. If it's changed a little, it's still working away. Again, some yeasts will take a looonnnng time to get to finishing gravity. I'm a beer and cider brewer and have had some brews take two weeks during primary fermentation to finally finish out. Depending on factors mentioned above, i've read it can take longer in some instances.

Secondary fermentation, if the same for wine as in beer and cider, is not the same process as Primary. Secondary is a process of aging and conditioning to bring out aromas and flavor. You won't see a lot of visible activity but science is indeed happening, just at a scale we humans aren't used to noticing.

I would sanitize a Wine Thief or turkey baster and check gravity with a hydrometer or refractometer. If using a refractomer, while you're waiting around for secondary, read up on refractometer calibration and how it needs to be adjusted once alcohol is present to get a more accurate reading.

I think your wine is fine. If you poured in un-sanitized tap water to top off, I would recommend boling or pastuerize it in the microwave next time and allow it to cool to room temp with some plastic wrap over it. Otherwise, this can introduce infections/bacteria into the brew. Since you did it so late in the process, it's likely there was enough alcohol created already that any pathogens weren't able to take hold but just be aware. Always santize everything you possibly can before adding to your brew.

Good luck!