Back Sweetening Wine After Fermentation Or Before Bottling

Wine Glass Full Of Sugar CubesIs it ok to back sweeten a wine right after the fermentation or should I wait?
Hello Terry,
Before back sweetening a wine, it is important that you wait until the fermentation has completed. It is also just also important that the wine have plenty of time to settle out all the yeast. Most often, the yeast has not had time to do this by the time you do your second racking. So, normally you will not want to back sweeten your wine right after the fermentation.
In reality, the best time to back sweeten a wine is right before bottling. This gives plenty of time for the wine to clear up. There is no upside to sweetening the wine sooner than this, only a potential for problems.
The reason clearing the wine is so important is because the wine be in a stable state before sweetening, otherwise all the new sugars that are added will end up as fodder for a renewed fermentation.
Cloudiness in a wine usually indicates it still has excessive wine yeast. The wine yeast is as fine as flour and settles out the slowest, so it is that last thing to be suspended in the wine. It is very hard to stabilize a wine that has residual wine yeast still floating throughout the wine.
The wine stabilizer, potassium sorbate, is what has to be used to stabilize a wine when back sweetening a wine. While a sulfite such as sodium metabisulfite or Campden tablets should be used as well, all of this is still not enough to completely stabilize the wine if too much residual yeast is still in the wine.
Shop Potassium SorbatePotassium sorbate stabilizes a wine in an entirely different way than these two sulfites. It does so by putting a restrictive coating on the outside surface of each of the few remaining yeast cells. This does not kill or destroy the yeast. They will die on their own in hours or days. But it makes them unable to reproduce themselves. The ability to reproduce is the real threat that can manifest into a full-blown fermentation.
If the wine is still even slightly, visually cloudy, there may not be enough potassium sorbate to go around to do a complete coat all the yeast cells. This is the downside to back sweetening the wine sooner then necessary.
In a nutshell, don’t back sweeten your wine right after fermentation. Give it plenty of time to clear, then back sweeten. And if convenient, don’t even think about back sweeten you wine until right before bottling.
Happy Wine Making,
Ed Kraus
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.

17 thoughts on “Back Sweetening Wine After Fermentation Or Before Bottling

  1. Does adding potassium sorbate change the flavor of a wine, and if not, can add a double dose to help ensure all yeast get coated?

    • Michael, adding potassim sorbate does not change the flavor of wine. As long as you add the recommended dosage for the product, there is no need to add an extra dose.

  2. Is it possible for the added sugar to create sediment in the bottled wine?
    I let my strawberry wine clear for three months. I racked it twice during this time and it looked very nice and clear.I added sugar and Potassium Sorbate and bottled it right away. In a couple of days after bottled, each bottle had quite a bit of sediment.
    Since the wine was stable and clear, I do not understand why there was sediment . Is there any reason why the added sugar would cause sediment? Should have I waited some time before bottling for possible sediment to settle?
    Thanks .

  3. my wife wants me to make a sweet red wine for her. She likes sweet on the order of Moscato, late harvest, or even dessert wine like ice wine. She likes a sweet red muscadine wine but I don’t know of a naturally sweet red wine grape. Does someone sell muscadine wine kits for home winemakers? Is there a trick to making red wine sweet? Thanks

    • Ed, we do not carry a Muscadine Wine Kit. However, you can make any wine that you make sweet after fermentation. Once the fermentation is complete for any wine that you make , it will be dry. Back-sweetening is how you make the wine sweet. Please take a look at the article posted below for more information.
      Making Sweet Wines

  4. I back stabilized and back sweetened my wine. It had cleared but now it is a little cloudy. I am bottling it now. Should I be concerned?

    • If that cloudiness came from a dusting of sediment that was overlooked before stirring in your sugar and stabilizer, yes you should be worried. That overlooked sediment is most likely dormant yeast cells. Potassium sorbate — which is the stabilizer I am assuming you used — will not be able to stabilize a wine with that much noticeable yeast with any certainty. The wine needs to be free of any visible signs of yeast before relying on potassium sorbate. I would suggest that you stop bottling; leave the wine in the vessel; and give it time for the yeast to settle out again. After that, you can siphon the wine off the sediment, add stabilizer again, and then bottle.

  5. Is there a certain time period to wait after stabilizing before back sweetening?
    Also, when you have to add vodka to wune in order to bring the lwvel up in your carboy, does the vodka affect the taste of the wine?

    • Judith, there is no time period that you have to wait after adding potassium sorbate. You can sweeten the win at the same. time. Adding vodak will alter the taste do to the fact that it has more alcohol.

  6. Hi, is there any recommendation in the quantity that needs to be added of potassium sorbate?
    For example a ratio between sugar and potassium sorbate?
    Thanks for your support!

    • The short answer is no. The potassium sorbate is not related to the sugar. It is related to the yeast. It stops the remnant yeast cells that are in your wine from multiplying into a viable colony and fermenting the newly added sugars. If you add the standard dosage of potassium sorbate that is recommended on the container, you will be fine, regardless of how much sugar you add to the wine.

  7. My (concord grape) wine started a second fermentation after back sweetening , now it has an odd smell and taste. Kind of sour and musty. I want to say a bit vinegary. Is it ruined? Or can I do something to fix it?

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