How to Dilute Wine to Make Vinegar

Acetobacters have a difficult time breaking down alcohol in concentrations greater than 9%.  If you want to make wine vinegar, you will probably need to dilute your starting wine with water before adding the mother culture.  On this week’s YouTube video, I show how to use cheap red wine to make a delicious vinegar.

General Dilution Equation

In order to reduce the percentage of a alcohol in wine, first you need to use the general dilution equation which is:
Whereby C1 and C2 are the concentration of the alcohol before and after the dilution (reduction of concentration), respectively. In my case, the initial ABV (alcohol by volume) or C1 is 13% and C2 is 9%. Assume that you have a gallon or 128oz of 13% ABV red wine, and you want to dilute using water as the diluent to achieve a 9% ABV wine, the equation can be re-written as:
(13%)(128 oz) = (9%)(V2)
Solving for V2, the final volume (V2) = 185 oz
The final volume includes the initial volume, in other words : V2 = V1 + V(additional water)
In my case: 185 oz = 128 oz + V(additional diluent)
Thus, V(additional diluent) = 56 oz of water required to reduce a gallon of wine to 9% ABV

An Example

In the video, I used 64 oz of wine.  I added 24 oz of old vinegar and mothers to get 88 oz of liquid.
(13%)(64 oz) = (x%)(88 oz)
Solving for x, 13 times 64 divided by 88 is 9.45%  Good thing I topped up my crock with some water before putting it away to become vinegar!  That would have driven the ABV well below 9%


About John MacDowall



  1. Is it possible just to say 2 to 1 etc or just give it in oz’s? Geeze.. Need my algebra 3 book for what you got here.

  2. Got it, John. You must be an engineer. I am, but these days I’m home fermenting.



  3. Just one final question. Is the 64 ounces just wine, or is that the diluted wine, with the 28 ounces of water added, where you then added 24 ounces of vinegar to get the 88 ounces? The water variable seems to be missing in the second equation, though I think I get your intent here extrapolating the information given in the first equation.



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