Hops (Humulus lupulus) are a key ingredient in beer, providing bitterness, flavor, and aroma. Hops are the female flowers (or cones) of the hop plant, a climbing vine that is a member of the Cannabaceae family, which includes marijuana. The hop plant is native to Europe, Asia, and North America. It’s a type of climbing vine that can grow up to 20 feet (6 meters) in length. The hop plant is a perennial, meaning that it grows back year after year.
What kind of a plant are hops?
Humulus lupulus is a dioecious plant, meaning that there are male and female plants. Only female flowers are used in brewing. The hop plant produces cones (or strobiles) that contain resins and oils that provide bitterness, flavor, and aroma to beer.
How do hops affect beer?
Hops are divided into two main categories: bittering hops and aroma hops. Bittering hops are added early in the brewing process to provide bitterness, while aroma hops are added later to provide flavor and aroma.
Hops add bitterness to beer by providing alpha acids. These acids isomerize in the boil to form iso-alpha acids, which are responsible for the perceived bitterness in beer. Hops also provide essential oils, which contribute to the flavor and aroma of beer.
The bitterness of hops is measured in bitterness units (or BU). One BU is equivalent to one part per million (ppm) of iso-alpha acid in wort or beer. The percentage of alpha acids in a hop variety is typically between 4% and 6%.
