How is alcohol measured?

How about calories?

Many craft breweries use hydrometers to measure beer density before and after fermentation. The change in density can be used to calculate alcohol by volume (ABV).

This process isn't always accurate.

Accuracy is important in beer measurement for consumer transparency. There have been many alcoholic beverage recalls due to incorrect ABV recording.

At Good Robot, we use an Anton Paar Alcolyzer.

Using near-infrared spectroscopy to see how alcohol molecules react with light, we can accurately measure density, sugar, calories, alcohol by volume (ABV) and more at any step in the brewing process.

Fun fact: The strongest beer in the world is 67.5% ABV.