hi guys i'm very new to this beer brewing business. ill be be having a small party this weekend, I'm short on beer, So I'd like to know how do i go about doubling my alcohol volume when diluting it with water?

  • Ideally, you just make more beer, but one week is too short of a delay... no miracle possible.
    – Philippe
    Nov 4, 2015 at 15:36

3 Answers 3


You don't. Watering down beer is bad idea, because you will end up with something with no taste, no kick etc. You could add vodka or rectified alcohol, and something for taste, but due to tax rules on strong liquor in most countries it would be far cheaper to simply buy more beer.

  • Actually, this is a very common process for commercial brewers. They brew beer a high ABV beer and dilute it after fermentation. Nov 4, 2015 at 8:56
  • 1
    @AtronSeige HGB is not the same as diluting because someone is short on brew. And it's not what OP is doing - if it were, he would ask before fermenting anything in the first place.
    – Mołot
    Nov 4, 2015 at 9:23

If you absolutely must do this, I would buy an mildly flavored (or similarly flavored) commercial beer with a similar ABV and mix it into your beer. It might even still be good. Serve in pitchers and no one needs to be wiser.

If you must add water, you probably need to dilute it with vokda or some other (preferably neutrally flavored spirit) to maintain ABV. But then you need to pull out your algebra skillz to calculate the right ABV of watered down vokda. x oz of 100 proof spirit (50% alcohol by volume) added to y oz of water* would raise the water's ABV to (0.5x)/(y+x). So if target ABV is 5% and you have 1 quart (32 oz) of water, solve for x in 0.05=0.5x/(32+x) to figure out how many ounces of 100 proof spirit to add. That comes to about 3.5 oz; multiple by 4 if you want to deal with gallons instead of quarts.

(*) you could also try alcohol-free beer, which may not be too expensive and also could be better for flavor than water


The easiest way: experiment. Take a small glass of beer, dilute to a measured amount and taste.

Diluting beer is common in commercial breweries, but they start with the knowledge that the beer will be diluted, so they ensure that they have strong ABV, body and flavours to carry through in the final product.

Your chances of just ending up with a watery, low ABV and flat tasting beer is very high.

I would say that you should server your beer and when it is done serve some other commercial beer. Then people can taste what you brewed, not some watered down effigy.

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