Written by: Tim Edison

Updated: July 13, 2023

4 Ways to Stop Wine Fermentation [Ultimate Guide]

One of the greatest challenges in winemaking is stopping the fermentation.

Fermentation is caused by the yeast which consumes the sugars from the wine and turns them into alcohol.

The fermentation process generally stops on its own when there is no sugar left (so you will have a really dry wine) or when the alcohol concentration reaches about 14-18%, depending on the yeast strain.

However, the question about how to stop fermentation in winemaking rises when your wine reached the desired level of sweetness and you want to keep it just as it is.

So, let’s see how to stop fermentation with three simple methods.

1. Adding Sulfites

If you need to stop an active fermentation then the best way to do this is using sulfites.

However, be aware that this technique is only really effective for fermentations that are nearing completion. You wouldn't want to try and stop an energetic fermentation in this way.

Once the target sugar level has been reached (this is measured using a hydrometer) we add sulfites to the wine must.

Commonly used sulfites in winemaking are Campden tablets, sodium metabisulfite, and potassium metabisulfite.

The temperature then should be reduced to further inhibit fermentation. Below 40°F is ideal for this.

This will stop the active fermentation by stifling the remaining activity, but our work isn't yet finished.

A wine that hasn't fermented to dryness and still contains residual sugar needs stabilized.

This means we need to stop any remaining yeast cells from reproducing and starting to ferment again.

We've stopped one fermentation but another one can begin because the leftover sugar can help yeast reproduce again. 

To inhibit further yeast growing, we add a stabilizer called potassium sorbate. The potassium sorbate essentially makes the yeast sterile and unable to strat working again.

You might wonder why we don't use this in the first place to kill off the active fermentation and that's a great question!

It simply doesn't work like that and can only inhibit new fermentations from starting. Potassium sorbate is a bit like a contraceptive for wine yeast!

We must kill off as much yeast as possible with sulfites first.

2. Stopping the Fermentation with Cold Shock

This is the method a winery would use and it's very effective. However, it's labor and time intensive as well as expensive as you need a wine filter.

To stop the fermentation, follow these steps:

  • Place the wine in a very cold room or in a refrigerator, at 36-50 degrees Fahrenheit (below 50 degrees is fine), for at least 5 days (longer is ideal, perhaps 10 days). If you leave the wine in a cold warehouse, pay attention to the temperature at all times because it is essential that it stays above the freezing point.
  • During this time the fermentation will completely stop and the yeast will precipitate. You will notice the sediment on the bottom of the demijohn and a partial clarification of the wine. You can add bentonite to help the wine clear.
  • Remove the sediment by racking the wine into another sterilized demijohn. 
  • Filter the wine through a wine filter into another sterilized demijohn. You must filter using a specialized wine filter that will remove yeast cells. These can be quite expensive devices.
  • Leave the wine at normal temperature for at least a week and check on it daily. If you notice any signs of fermentation, repeat the process.

The downside of this method is that some of the yeast can be filtered with the wine during the racking process and the fermentation will start again.

You can prevent this by adding potassium sorbate.

3. Stopping the Fermentation Through Pasteurization

Probably the most efficient method for killing the wine yeast is pasteurization.

Yeast normally dies at temperatures above 104 degrees Fahrenheit, so to stop wine fermentation it is sufficient to heat the liquid above that point.

Here is how to stop fermentation with this method :

  • Rack the wine into a sterilized pot.
  • Heat the wine to about 158 degrees Fahrenheit and maintain this temperature for about 10-20 minutes. This will kill not only yeast but also other organisms present in the wine.
  • Cool the wine down to 50-61F° as quickly as possible.
  • Bottle the wine immediately and seal it hermetically.

Alternatively, you can rack the wine directly into the bottles, pasteurize the bottles then seal them.

The downside of this method is that it is difficult to maintain a constant heat for 15 minutes and it is difficult to cool the wine quickly enough.

This process will alter the wine’s flavor and in order to be effective, you should minimize as much as possible the contact of the wine with the outside environment after pasteurization.

4. Stop the Fermentation with Alcohol

This is probably the simplest way to stop fermentation in winemaking. But one that requires expert blending knowledge in order not to ruin our wine.

As we mentioned earlier, yeast stops working when the alcohol concentration is about 16%.

Actually, depending on the yeast strain, the alcohol concentration can be between 14% and 18%.

So you can stop wine fermentation by simply adding more alcohol to your wine, in essence fortifying it. When fortifying wine to stop fermentation you want to bring the ABV up to 20%.

This is how to do it.

  • Rack the wine into a sterilized demijohn, in order to remove all the sediment from the wine.
  • Add alcohol to the wine until you reach a concentration of about 20%. The alcohol should be either grape distillate, vodka or brandy.
  • Leave the wine for another week and see if you notice any sign of fermentation. If you don’t, you can rack the wine one more time, then proceed to bottling.

The downside of this method is that the added alcohol will not only alter the flavor but if you use vodka, it will also give an unpleasant smell to the wine.

Have you ever stopped wine fermentation before? What method did you use? If you have any questions or tips on how to stop fermentation in winemaking, please leave a comment below.

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About the Author Tim Edison

Tim started Wine Turtle way back in 2015.
These days he contributes to Wine Turtle (and other renowned wine publications) while continuing his wine education.
Tim's wine of the month is the Coates & Seely Reserve Brut NV (from Hampshire, England).

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  1. One other way to stop wine from fermenting is to use a low alcohol tolerant wine yeast (i.e.: 11-13% alcohol), or mead yeasts that stop at ~5-7%.

  2. Use commercial yeast which dies when it hits a specific alcohol percent.

    so work out with a hydrometer the level of alcohol of which the commercial yeast you have chosen would die at and add sugar to surpass this % to make it sweeter.

    Easy peasy.

  3. Quite often, I’ll have someone ask me how to stop a fermentation before it is ready to stop on its own. Usually the reason for asking is because they have tasted their wine and they like the amount of sweetness it currently has.

    Stopping the wine from fermenting any further would preserve the current level of sweetness. And likewise, allowing the wine to continue fermenting further would only make the wine less sweet with each passing day.

    Great tips. Thanks for sharing 🙂

    Sarkis, 3foxes.com.au

  4. I am by no means a winemaker and/expert but I stop the fermentation process by bringing To just below boiling point then turning and scooping for an hour as it cools. I add natural cane sugar and repeat process over a week.

    I then add a couple of shots of jack Daniels plus soft dark fruits in season for a week and bring to point every couple of days.

    At this point the pot starts to produce the sediment and that is scooped out until effectively clear.

    I then leave for a week outside before returning to cook on very slow heat before processing via blender and straining back into base pot that takes a couple of hours.

    Once again heated through to encourage any lasting fermentation to be removed next day!

    All I can say is that everyone thinks they are drinking a fab juice until “it kicks in”

  5. I am new to wine making,, My problem is that after fermentation my wines taste horrible, not vinegary but it doesnt taste good at all,, I add sugar to back sweeten and its fine but then I have corks being pushed back out of the bottles and Ive had 2 of them explode! (That was a mess)
    Any help would be appreciated,,,

    1. Hi Dale,

      Can you describe the bad taste at all? What recipe are you using?

      The corks are being pushed out because fermentation is starting again (or it may have never stopped). The wine yeast is feeding off of the added sugar.

      Ideally, we shouldn’t need to backsweeten and this can be avoided.

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