HOPS
Hops are the flower cones from the hop plant (Humulus lupulus) and have traditionally been a main component of beer for over 200 years. Hops, grown in various countries around the globe, are rapidly growing vines that can reach 15 feet in height. In beer, hops contribute aroma, flavoring, and bittering characteristics as well as preservative qualities. Different varieties of hops are typically used to provide different characteristics to a beer. Hops can have intensely fragrant floral and spicy aromas, and are very bitter when tasted. The bittering compounds in hops are called alpha acids, and each variety and seasonal crop is rated by its alpha acid content, which describes what percentage of the weight of the hop is alpha acid.
Beers can contain one or more different varieties of hops. During the brewing process, hops are typically added to the wort at different times during the boil. The boiling process drives out the fragrant, volatile oils and leaves behind the bitter compounds. So-called bittering hops are added early in the boil, and so-called aromatic hops are added late in the boil so that their aromatic quality is left intact. After the wort has been boiled the hops are typically strained out before the wort is racked to a fermenter. Dry-hopping is the addition of hops to the beer during fermentation which imparts a very fragrant aroma to the finished product.
Hops are typically purchased by the home brewer in pellet form. Hops pellets are made by chopping whole hop cones and compressing them into small pellets which are then sealed in air-free bags. This preserves the hops and lengths their shelf life. Whole hops can also be purchased and used for brewing, although this is less common as they do not remain fresh as long as pelletized hops.
In the right climate hops can be grown at home and used for brewing. Some homebrew stores also sell hops rhizomes which are root clippings from hops vines, and these rhizomes are planted to grow new vines.
- Ken Blair