Lowering The Alcohol Level Of Wine With Water

old man drinking wineCan you tell me when to add water to my wine, is it during fermentation or after? I make wine using Cabernet Sauvignon and Zinfandel grapes mixing 50 /50, but it always comes out very strong,  I like that smooth taste, any suggestion?
Thanks Joe,
Good Morning Joe,
Both of the grapes you mentioned are normally made using 100% grape — no water added. This isn’t the case with all grapes, just with wine varietals such as these. They will produce a wine anywhere from 11% to 13% depending on how the growing season went that particular year.
If you want to lower the alcohol level of your wine with water, the optimal time to add it would be before bottling. The wine is clear and stable and can easily be blended with water.
It is important that you use distilled water at this stage of the winemaking process. Tap or bottled drinking water has oxygen saturated in it. The oxygen in this water can promote oxidation in the wine if it is added.
How much distilled water you add is entirely up to you, but I would suggest that you keep the wine at an alcohol level of 8% or above. Wines below this have a harder time protecting themselves from spoilage. For the same reason, I would also urge you to add sulfites to the wine before bottling. This could either be by way of Campden tablets or potassium metabisulfite. Either of these will help to protect the wine.
The only way to know with certainty how much distilled water to add and still keep the wine above 8% alcohol, is to start by knowing how much alcohol is in the finished wine. This will require the use of a wine hydrometer. The hydrometer will allow you to determine how much alcohol is in your wine. You will need a reading taken before the fermentation and another one after the fermentation. By comparing the two hydrometer readings you can calculate the alcohol level of your wine.shop hydrometers
To know how much distilled water to add to get from your finished alcohol level to the one you desire. I would suggest you use a tool called the Pearson Square. It is a method of calculating ratios when blending two different wines. In your case you are blending wine and water. Use the Pearson Square in this way. The distilled water is 0% alcohol.
Lowering the alcohol level of a wine with water is something that is not typically done, however rested assured that if you use the methods above you will have no problems with getting your wine safely to an alcohol level you prefer.
Happy Winemaking,
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.