problems with fermentation

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Dec 30, 2007
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I recently started a grape wine with a recipe that I have used before but with a few minor changes. I have never had any problems with fermentation before, but this time I made a starter and have never done that before. I've always just added the yeast directly to the must. The yeast in the starter seemed to be working just fine. I added it to the must and checked on it 24 hours later. All the yeast seemed to have gathered in alot of little clumps throughout the must and no signs of fermentation. I waited another 24 hours and the clumps went away and there is foam on the surface of the wine now, but it seems very slimy though. Usually the fermentation has taken of by now, but there isn't really alot of activity. What would have caused this and what should I do?

Wine Maker

Jun 9, 2007
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Hi Nate, what did the starter look like before you added it and did you follow the directions in regards to the temperature of the water added to the yeast? If the water was too hot, it will kill much, if not all of the yeast. The starter, after 15-20 minutes should have been foamy.

Did you sulfite the juice before adding the starter and if so, how long after the sulfite addition was the starter added?

Do you know the temperature of the juice when the starter was added? To hot or too cold can affect the yeast. The ideal temp range is 68-77 degrees F.

I don't know what would cause the yeast to float to the top and look slimy. You can try to add another starter. Too much yeast wont hurt as the yeast cells will fall to the bottom once all the sugar in converted to alcohol.


Dutch Winemaker
Nov 5, 2006
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A yeast starter is best made from the juice the yeast will be
living in. If that juice is not available try apple-juice.

The yeast needs all the things that is used for a healthy fermentation like nutrient, sugar and acid. But the best thing is not to use sulphite in the starter.
A starter will then start fermenting the juice just like in the real must only in a small quantity. Air is introduced by making the starter in a open bottle.

Each 20 minutes or so the yeast will multiply so after one to two days you will have a healthy colony which is then added to the rest of the must.

I wrote an article on the how and why of a starter on my web-log.
Look in the archive (right side on the page and on the archive page look at the augustus 24 entry:

There you will find pictures also from several healthy yeast starters, so you will know how it should look.

Yeast should not be floating around in clumps but the yeast should be 'dissolved' in the yeast.

Maybe your yeast was not working at all. And just a low part of the yeast was still alive so therefore the fermentation is starting very slow.

You could at this moment de-hydrate some more yeast and add it to the must to help speeding things up. There is no problem in adding more yeast.

I wonder if your must is protected by sulphite.
If not: do so now. It could be that your yeast starter was not working and that a fermentation has started with wild yeast that was in the must.

You could also wait and see how it turns out.
But if this is a large batch I would not be willing to take the risk.
I would add more yeast.