An ode to the most humble hop
Who in fall its rhizome’s do drop
The cone from the vine
Adds grapefruit and pine
To give my pale ale bitter pop
What exactly are hops?
The hop, Humulus Lupus, is a climbing plant in the Cannabacinae (nettle) family. Commonly referred to as a vine hops are actually a bine, which has a stout stem with stiff hairs to aid in climbing. These bines grow quickly, wrapping clockwise around anything within reach. Only the female plants are grown in hop fields to prevent the production of seeds by the male plant. The part of the plant useful in brewing is the cone (scientifically known as the catkin or strobile). Inside the cone is a stem surrounded by a waxy substance called lupulin, which contains the bitter resins and aromatic oils beloved by beer enthusiasts. The resins are divided into alpha and beta acids with the alpha acid being the measure of the hops bittering power (ranges from 2 to 20 percent). Recently high-alpha varieties have been developed in the unending quest for the hoppiest of the hopped beers. The oils have their own characteristics that can be described as floral, resiny, spicy and even minty. The differing aromas tend to be region specific; German hops are more herbal, English varieties tend to be spicy or fruity and American types, while quite diverse, lean towards piney-ness. In addition, there is a group of European hops termed ‘noble’ that are used for the distinctive aroma found in lager beers.
How and where are they grown?
Hops can be grown in both hemispheres between 35 and 55 degrees latitude. The hop plant is trained to grow up stings in a field called a hopfield, hop garden or hop yard. Hops are harvested in early fall and dried in an oast house. The majority of harvested hops are used in beer production; however, hops are also used in herbal medicines to treat anxiety and insomnia. In Europe and North America the most prized varieties of hops are tied to specific growing regions: for instance, the spicy saaz is grown in western Bohemia, the herbal Hallertau in northern Bavaria, the twangy green spiciness of the East Kent Golding grown in south-eastern London or the grapefruit happy Chinook and Columbus grown in the Pacific Northwest. Another unique varietals include Sorachi Ace the lemony hops grown in Japan. Locally, both Rogue (Oregon) and Driftwood (Vancouver Island) have brewed using their own locally sourced hops for some amazing, but transient, fresh hopped beers. Rogue Ales have a series of Grow Your Own (GYO) beers celebrating the use of local sourced hops.
According to Mosher in Tasting Beer the first hopped beers appeared in Bremen, Germany at the start of the eleventh century. Many of the first brewers to use hops were ‘free’ cities that operated beyond the reach of the Church. At this time the Church mandated the use of gruit (a mix of seasonings), which was sold by the local Gruitrecht, which just happened to be controlled by said religious organizations. Gruit brewers were making amber or brown ales while the hop brewers were crafting ‘white’ beers, which contained a fair amount of wheat. It took about one hundred years for these hoppy ales to spread to Amsterdam and about five hundred years to make it to the English shores. So why did the addition of hops to beer endure? One of the many great qualities of the hop is its preservative properties, which lengthened the shelf-life of beer (from a few weeks to a few months). Despite the reservations of the English towards this new import beer eventually hopped beers became the norm and by the 1600’s all English ale contained some quantity of hops.
What do hops bring to the table?
To get the bittering quality from hops you must boil them vigorously but this causes the aromatic oils to be driven off. To achieve balance in this aroma/bitterness dichotomy hops are added at multiple stages of the brewing process. Adding hops to the boil facilitates isomerisation, the process by which hop alpha acids are chemically rearranged into a form that is more bitter and soluble. Each variety of hop has a certain amount of bittering substance, which varies by region and year. This information is provided with the shipment. Balance, of course, is something subjective so the brewer must take into account the appropriate ratios for each beer style as well as leaving room for their own creativity. It is not merely a balance between the malt and hop but the consideration of the subtle interplay between the differing qualities of roasted malts, the variety of hop and other spices/elements that will be added to your brew. Generally the ratio of Bittering Units (BU) to Gravity Units (GU) will get you started in your calculations.
How do I describe the hoppiness in my Beer?
Aroma – Comes from the aromatic oils extracted during the different stages of the brewing process. Described as hoppy, spicy, herbal, floral, lavender, piney, resiny, citrus, earthy and/or cat pee.
Taste – Comes from the isomerized alpha acids. Described as bitter, hoppiness (medium to high to very high).
IBU (International Bitterness Unit) – This is a measure (parts per million) of the actual bitterness of a beer as contributed by the dissolved alpha acids