Link Search Menu Expand Document

Hydrometers for Home Brewing

When brewing an alcoholic beverage, it is possible to measure the total amount of alcohol produced during fermentation. This is often noted as “ABV”, or alcohol by volume, on a beer or wine label. When fermenting beverages at home, home brewers rely on a thermometer and hydrometer to determine the final amount of alcohol in their brew. It works by measuring how dense a liquid is expressed in gravity, or density relative to plain water. This can be then be used to determine much sugar is in a liquid both before and after fermentation, and therefore, the amount of alcohol produced by the sugar-eating yeast.

The other use of a hydrometer is to track the fermentation process over time. A brewer uses periodic measurements to determine if a brew has stalled out or if it’s ready to be bottled, for example. The timing of the fermentation can be used to help make decisions that effect the final beverage and offer insights that allows a brewer to replicate a successful batch.