Alcohol by Weight vs. Volume

You may have heard the terms alcohol by weight (ABW) or alcohol by volume (ABV).  What is the difference?

Alcohol by weight is the weight of alcohol in a drink divided by the total weight of the drink.  It is expressed as a percentage.  ABW is not used as much as ABV.

Alcohol by volume is describes how much alcohol is in a drink expressed as a percentage.  For example, a Sam Adams Boston Lager is 4.9% ABV.  You will not find the ABV on all bottles or beer menus, but I think you should.  Drinking responsibly means knowing how much alcohol you a drinking.  Bell’s Hopslam Ale is 10% ABV which means you can drink twice as much Boston Lager than Hopslam and still consumed less alcohol.  ABV is also related to the proof in liquor.  An 80 liquor is 40% ABV.

How do ABW and ABV compare?

The ABW of a beer is roughly 4/5 of the ABV.   A beer that is 3.2% ABW is about 4.0 ABV.  This is a rough estimate because the weight of water and alcohol differ.

Tags: ABV, ABW, Definitions