Slow Fermentation on a Welch's grape juice wine.

A couple of issues come to mind. Is it in a cool environment? This will slow down fermentation. To kick it up, you could move it some place warmer. The other issue may be a lack of nutrients. It is possible the commercial juice does not have enough for the yeast to really flourish. You could add some yeast nutrients and see if that helps.

Another issue you will want to consider is when you add your stabilizers. It will not halt fermentation immediately (sometimes not at all). This is because they do not kill the yeast, but only prevent them from reproducing. Thus, any live yeast will happily continue to ferment away until they reach the end of their life cycle. If you have a lot of yeast and an active fermentation, you may end up a lot lower in sugar than you intend. You could try to add your stabilizers when the sugar is a couple percent higher than you want in the end. A better way may be to chill your wine to close to 30 degrees or so and let the yeast stop and settle out at the alcohol/sugar level you want. When it has cleared well, rack it (still cold) to remove the yeast-laden lees. Then add your stabilizers.

The best method is to plan for the amount of alcohol you want and ferment to dryness. When the wine has cleared and you are getting close to bottling, stabilize and sweeten to taste.

Greg answered most of your issues but on the "needing air": Yeast need air early on to reproduce and build up the colony. After the ferment is going good they no longer need air and the air will damage the wine so it should be blocked with the air lock. Some batches are just slower than others. I have not made a pure Welch's batch but I intend to. Maybe someone with experience can comment on it being a little slower than other wines.

Ray

Welch's (like some of its competitors) contains 120ppm K2S2O5 (potassium metabisulphite). It needs aeration.

With proper sugar and acid adjustments, in a loosely-covered primary, stirred twice daily, it will ferment to dryness within 3-5 days (at

75-80ºF). In a carboy, it will take much longer, and (with the same sugar levels) tends to stick.

Well, I've had a Welch's fermentation going for about 3 months now. Living in the northeast Us, and being a conservationist, my cellar temperature is in the 50s at best, so slow going is expected. So, I just make bigger batches! I prefer the taste of slow, cool ferments anyway.

Tom (or Shelley), the others have already made the most salient comments, but the first thing I'd do is check your fermentation temperature and then go to

and see if it is optimum for the yeast you are using. Of course, I don't list the optimum for all strains, but most of the ones you are liable to use in the States are indicated. You didn't mention what strain you are using or I would have already checked it for you.

Welch's usually ferments pretty evenly. You may have a nutrient deficiency, as has been mentioned, in which case a half-teaspoon of nutrients dissolved in a half-cup of the wine and stirred back in will help. On the other hand, there is nothing wrong with a fermentation that slows down, as long as it doesn't stop. I don't care how fast a wine ferments, I'm not going to rack it until it has been in the carboy for a month anyway. More potentially good wine is ruined from hurrying it than from forgetting it for a while.

Good luck, and let us know how it turns out.

Jack Keller, The Winemaking Home Page

Hello again, Sorry it has taken me this long to reply. I've been working 2 jobs and I have a friend in the Hospital so I've been running around a lot this week. I am pretty bad at keeping records and to be honest I'm not sure what yeast I used. I know it was a Red Star dry yeast and it was either the Pastuer Red or a Montrochet. The first batch (Concord Grape) was started on 11/02/03 with a brix of

1.098. After 5 days I put the airlock on and the fermentation began to slow. Currently the brix is about 1.040 and has been right around that for the past 4 or 5 days. It seems that it may have stopped. The second batch (Niagra Grape) was started on 11/9/03 with a brix a little high around 1.11. Again, after 5 days I put the airlock on. Currently the brix is about 1.070 but I have not been checking it as often to see if it has stopped or not. The two carboys are in my basement sitting on the basement floor (on top of an couple sheets of cardboard). I never had any problems getting anything else to ferment there but it is getting colder. The basement temp us pretty stable but it may have dropped a few degrees this fall. Right now the temp is around 65 degrees. If this is the problem then I have an old waterbed heater that can be set from 70 - 100 degrees. I could either set the carboys on this or wrap it around them. I would have to do a little testing first to see is those settings are accurate. As far as nutrients, I followed Jack Keller's recipe. If needed I could add some more to both batches. Thanks again for you help. Tom

Hello again, Sorry it has taken me this long to reply. I've been working 2 jobs and I have a friend in the Hospital so I've been running around a lot this week. I am pretty bad at keeping records and to be honest I'm not sure what yeast I used. I know it was a Red Star dry yeast and it was either the Pastuer Red or a Montrochet. The first batch (Concord Grape) was started on 11/02/03 with a brix of

1.098. After 5 days I put the airlock on and the fermentation began to slow. Currently the brix is about 1.040 and has been right around that for the past 4 or 5 days. It seems that it may have stopped. The second batch (Niagra Grape) was started on 11/9/03 with a brix a little high around 1.11. Again, after 5 days I put the airlock on. Currently the brix is about 1.070 but I have not been checking it as often to see if it has stopped or not. The two carboys are in my basement sitting on the basement floor (on top of an couple sheets of cardboard). I never had any problems getting anything else to ferment there but it is getting colder. The basement temp us pretty stable but it may have dropped a few degrees this fall. Right now the temp is around 65 degrees. If this is the problem then I have an old waterbed heater that can be set from 70 - 100 degrees. I could either set the carboys on this or wrap it around them. I would have to do a little testing first to see is those settings are accurate. As far as nutrients, I followed Jack Keller's recipe. If needed I could add some more to both batches. Thanks again for you help. Tom