HBU
Homebrew Bitterness Units are a measure of the total amount of bitterness potential in a given volume of beer. Homebrew Bitterness Units are calculated by multiplying the percent of alpha acid in the hops by the number of ounces. For example, if 2 ounces of Northern Brewer hops (9% alpha acid) and 3 ounces of Cascade hops (5% alpha acid) were used in a 10-gallon batch, the total amount of bitterness units would be 33 (2 x 9) + (3 x 5) =18 + 15. Bitterness units per gallon would be 3.3 in a 10-gallon batch or 6.6 in a 5-gallon batch, so it is important to note volumes whenever expressing Homebrew Bitterness Units. HBUs are not related to IBUs (International Bitterness Units). HBU is a measure of alpha acids added to the boil, whereas IBU represents a measurement of the intensity of the bitterness of the beer.