Hops is considered the green gold of the beer making ingredients and was introduced relatively late to the history in brewing. Known as Humulus lupulus L., the hops plant belongs to the Cannbinaceae family. Hops contains no hallucinogenic compounds, but is dioecious and like its relatives, is generally eradicated of male plants. Although, both the female and male plants produce flowers known as cones.
Hops Growth and Cultivation
Hops grows as a vine and has hooked hairs that allow for it to climb. It is a herbaceous perennial plant that grows a annually starting in the spring from a permanent root (crown) which can penetrate to a depth of 15 feet. The start of its growing cycle is geared more towards the root growth which consists of both rhizomes (with buds) and true roots (without buds).
The shoots of the hops vine, called bines, can grow to lengths of 25 feet over a growing period. Large wooden posts are anchored in soil with the use of wire. The hops are planted beside the posts, and when the plant reaches about 1 foot in length, 2 to 6 of the healthiest vines are selected to continue, and the others are pruned. around the 2nd or 3rd month of the growing season the bottom 2-4 feet of the plant is further pruned, and cleared of lower branches in order to give more strength to the top of the plant, which is where most of the cones will form. This also allows to fight against disease and fungus.
Until fairly recently (1950's) all hops was hand picked. Today, however, this practice is nearly gone on a commercial scale. The process for removing the buds from the vines requires a few steps which are all automated. Prior to the automation converted farm houses and barns used for kilning and separating the cones. Today the processing is similar but done differently. The hop vines are sent to a picker which strips the leaves and cones from the vine. A process using compressed air, can then remove the leaves from the cones due to the difference in their weight and surface area. The cones are then taken to the oast house or kiln where they are dried. The drying process can span over 12 hours and a temperate of around 145 degrees Fahrenheit is maintained attempting to reduce the moisture of the cones to roughly 7%. From there they are baled or put into traditional hop sacks so that they can be tested for alpha and beta acids as well as graded for aromatic qualities, which is largely subjective.
Usage In Beer
Hops is used as a bittering agent, for aroma, and is used as a preservative. For example, India Pale Ales were originally brewed in England. Hops was added in substantial amounts to help preserve the brews as they traveled to India, thus the name. The aroma that comes from fresh cones is a floral bouquet that can raise your senses. At the same time hops contains bittering agents due to its production of alpha and beta acids. These acids help balance the the sweetness of malts.
Hops is sold commercially in two forms including whole cones and pellets. Cones are preferred for brewing as long as they are fresh, or have been kept well. Pellets help to preserve the hops by removing unwanted air pockets. Air will oxidize the lupulin which is created by glands in the plants. Lupulin contains the oils and resins that are beneficial to beer. While preservation happens by compressing the contents to pellets, the glands are also compressed and crushed.