Hops are largely associated
with beer today but in terms of the history of brewing beer they are a modern addition, since they date to sometime in the middle ages, probably sometime around the late tenth or early eleventh century. It's hops that give beer that characteristic hint of bitterness, sometimes with a nod at citrus. Hops contribute to the aroma, as well as the taste of beer. It's generally assumed that hops were initially added to beer as a preservative, and an antibacterial. There was a long tradition of adding other herbs as preservative before hops, but the theory is that some brewer somewhere noticed his hoppy ale stayed fresh longer. One of the interesting and important qualities of hops is that while they are naturally antibacterial, they do not destroy the yeast that is so very vital in terms of fermenting the wort, the grain and water base, that all beer begins with.
Hops or Humulus lupulus for the botanists among you, were frequently grown in medieval gardens for medicinal purposes; adding them to beer therefore, wasn't much of a stretch, but it was startlingly successful. We know that hops were deliberately, carefully cultivated by the ninth century in Bavaria in particular. By the twelfth century, there are brewer's recipes calling for adding hops to beer. By 1516, hops were so important and so requisite an ingredient in beer that the Reinheitsgebot or "beer purity laws" of Germany stated that the only acceptable ingredients in beer brewing were water, barley, and hops.
Hops is one of those
dioecious plants like marijuana or holly that have individual male and female plants. The actual hops used in brewing are the female plant's flower clusters. Hops are a perennial, and a lovely lush leafy climbing vine. Traditionally, hops are trained to climb up strands of string. You can see them climbing up strings against a fence in the image above, from the Boundary Bay Beer Garden. To the right of this paragraph is a picture of the female hop flowers. The flowers are picked in the fall, dried, and added to the beer wort, the grain, yeast and water mixture that all beer begins with.
Hops are now grown not only in Germany, but flourish in the Pacific Northwest, in both Oregon and Washington, and particularly, in Washington's Yakima Valley. There are lots and lots of kinds of hops, but in broad terms, they tend to be divided into "Noble Hops," and, well, other hops. Noble hops are especially valued for their aromatic qualities. Particularly well-known varieties of Noble hops are Hallertauer, Spalt, and Tettnanger; they tend to be Germanic stock, and often, are imported from Europe for U.S. brewers. The other sorts of hops are prized for their "bittering," their contribution to flavor. You'll especially see these hops, like Nugget, and Galena, associated with "hoppy" styles of beer like IPAs.
Image Credits: digitalmedievalist