What do wolves, marijuana and beer have in common? The answer is hops.
Ok, what’s up with the riddle? The fact of the matter is that the major ingredient which puts the bitterness, the herbaceousness, the grassiness and the dryness in beer is the hop, a perennial vining plant whose scientific name—Humulus lupulus—translates to "wolf among weeds." This botanical also belongs to the Cannabaceae family, thus making it a cousin of marijuana.
Even though nowadays it is difficult to find beer that is brewed without hops, for thousands of years producers did just fine without. Back then beer was flavored and bittered with a mixture called "gruit"—which could include any combination of herbs and spices including the floral shrub heather, herbs like rosemary and ginger, spruce tips, juniper berries, and more. This all changed somewhere in Medieval Europe. The first hops cultivation was recorded in 8th century AD in present day Germany and the first documented use of hops in brewing points to about a hundred years later. Over the next several centuries, hops became the fourth main component in beer production, in addition to water, malt and yeast.
The notion of terroir in wine, the idea that the area in which grapes are grown impacts a wine's flavor, also applies to hops and beer.
The importance of hops as a key ingredient in modern beer, and as an almost sole source of its bitterness, is highlighted by the fact that virtually all brews must now carry a numeric value, abbreviated as an IBU, which stands for International Bitterness Units. While the perceived bitterness of a beer depends on many factors, like alcohol content or residual sweetness, generally, the higher the IBU number, the more bitter the beer tastes. For example, ubiquitous American Lagers generally have an IBU range of eight to 18, while a beer style considered super hoppy like a West Coast Double IPA might have an IBU as high as 120 or more.
In addition to its bitter flavor, hops contain antibacterial properties that naturally preserve beer. Some beer historians believe that the increased shelf life hops provided (and still provides), led to the rise of certain beer styles, like the India Pale Ale (IPA) for example. Because the heavily hopped beer was able to withstand the long journey from England to India without spoiling, IPA became a very popular style, and continues to be so around the world.
In brewing, the part of the hop that’s used is the flower, from only female plants. Resembling a little green pine cone, its size, aromatics, flavor and strength differ from varietal to varietal, like wine grapes. In all types, the cone’s yellow lupulin glands contain different resins and oils whose ratio and composition determine, among other things, the quality and type of aroma and flavor of the hop, and ultimately the beer itself.
The notion of terroir in wine, the idea that the area in which grapes are grown impacts a wine's flavor, also applies to hops and beer. As such, hops used in brewing beer are divided into three major categories, classified by their geographical distribution: Noble (or Continental), English and American hops.
- Noble hops or Continental hops originated in central Europe and are considered the most classic. There are four noble varieties: Hallertau, Tettnang, Spalt, and Czech Saaz (some also say Hersbrucker). These hops, mostly used in low IBU lagers like Pilsners, are known for their spicy, floral aromatics and smooth bitterness. Try the classic Bohemian Pilsner Urquell, for quintessential Czech Saaz characteristics, or Samuel Adams Noble Pils, which is brewed with all of the Noble hop varieties for a citrusy, floral, mildly spicy beer.
- English hops were imported from Flanders near the end of the 15th century mostly for their preservative qualities in connection to beer. The bitterness they imparted gave way to maltier qualities of English beer styles like Porters and Stouts. The most common traditional English hops are East Kent Golding and Fuggle, which have herbal, earthy and woody notes. Other higher alpha acid varieties include Pilgrim and Target. Try the UK’s St. Peter's Best Bitter for a taste of Kent Goldings hops, or quaff Abbot Ale from Greene King Brewery for its English hop profile balanced by malty richness.
- American hops are known for being big, bold and bitter. Farmers cultivate more than 50 varieties for beer production in the United States. Bright, piney, citrusy and resinous, these are the signature hops of American IPA’s. They're used for both aromatics and bittering, with high levels of alpha acid. The most well-known American hops are the four "C’s": Cascade, Centennial, Chinook and Columbus. Other popular fruity varieties are Citra, Amarillo and Simcoe. Try Racer 5 IPA from Bear Republic, an American West Coast IPA brewed with the four C’s, or Ranger IPA from New Belgium, an amber IPA brewed with Cascade, Chinook and Simcoe.