How Long Before Wine Yeast Starts Working?

I bought your wine making starter kit and am up to the point where you add the wine yeast. I added the yeast about 12 hours ago and nothing has happened yet at all. Is this normal? The reason I ask is because I have made wine before in just a gallon milk jugs and added brewers yeast and instantly it foams. Can you please let me know…
Thank-You,
Harley
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Hello Harley,
The short answer is that you should expect to see activity of some kind within 36 hours, but usually within 24 hours. The fact that you are not seeing your wine working within 12 hours is not all that unusual. Just how long before your wine yeast starts working depends on numerous factors.
In regards to your previous batches, when making wine in a gallon glass carboy or something similar, it is expected that the fermentation will take off sooner. This is because you are using the same amount of yeast in a single gallon that you would be using in the typical five or six gallons of a wine making kit. The higher concentration of yeast cells, means your yeast will start fermenting sooner.
That’s the short answer to your question. The long answer is I don’t think there is a thing wrong with your wine must or wine yeast, but if you are still concerned I can go over some things that may put you more at ease.

• The #1 reason a wine yeast fails to ferment is temperature.
  The wine must is either too hot or too cold. Temperature plays a major role in how fast or slow a wine yeast starts to ferment. The temperature should be between 70 and 75°F. The further you get from this fermentation temperature, the harder it is for the wine yeast to start fermenting. If you are not sure what temperature your wine must is at, you may want to consider getting a wine thermometer.

• The #2 reason a wine yeast fails is improper re-hydration.
  The direction on most packets of wine yeast will tell you to re-hydrate the yeast in warm water before adding it to the wine must. The directions will specify a certain temperature for specific length of time. Normally, it’s something like 105°F. for 10 minutes. If you followed these direction, exactly, you will not have a problem whatsoever. But, if the temperature was hotter than the directions say, or if you left the wine yeast in the warm water for a longer length time than you were supposed to, you could have killed all or a significant portion of the yeast. If most of the yeast was killed it will take much longer for the fermentation to start. The fermentation may also be slow or sluggish once it does start.

In either of the above cases the solution is simple. Depending on the issue, either get the wine must to the proper temperature, or add another pack of wine yeast. Problem solved!
Just how long before your wine yeast starts working can depend on a number of different factors. The above two are by far the most common we run across, but if neither of these sound right, you may want to take a look at, “Top 10 Reasons For Fermentation Failure” that is listed on our website.
After have said all of this, it’s still only been 12 hours since you added the yeast. The most likely scenario is that it will have already started bubbling by the time you read this. While many fermentation will start before this, taking longer than 12 hours is not all that unusual.
Happy Winemaking,
Ed Kraus
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Ed Kraus is a 3rd generation home brewer/winemaker and has been an owner of E. C. Kraus since 1999. He has been helping individuals make better wine and beer for over 25 years.