Choosing Hops

Hops occupy an exalted place among the building blocks that make a great beer. There’s something special about an ingredient that can make a beer bitter and give it a delicate aroma, too.

Every brew with a new or unfamiliar hop variety becomes an experience made special by aromas sweet, pungent, floral, perfumy, or citrusy. And what brewer hasn’t celebrated hops to the point of making a beer so overhopped that only the brewer could (begrudgingly, yet still in denial) drink the bitter elixir?

There are more than a hundred hop varieties, and hops from every major growing region are readily available to U.S. homebrewers. In addition, hop breeders throughout the world introduce new varieties each year. Choosing the right hops for your brew can seem difficult amid all the options.

The three best known growing regions are the Pacific Northwest, Germany, and England.

Beer styles originally developed because brewers used indigenous grains and hops and local water. Climate and soil conditions dictated what grains and hops could be grown and thus defined the flavors of the beers that could be brewed.

Pilsner beers, named for the city of Plzen in what is now the Czech Republic, became nearly synonymous with the noble hops, most particularly the grassy and slightly spicy aroma of Czech Saaz hops. Today, Saaz hops are almost exclusively reserved for lager beers, because their aroma is so distinctly associated with the style.

In Britain the English Golding hop was cultivated circa 1775, and in 1875 the Fuggle hop was introduced. These two, the most widely known English hops, became the signature of English ales. Golding varieties in particular have been prized. The hops company HopUnion USA in its catalogue describes East Kent Goldings as “the undisputed finest ale hop in the world.” The heavier and maltier profiles of English ales are perfectly balanced by the sweet and slightly cloying aromas and flavors of Goldings and other English varieties.

In the United States, where so much of the culture has been borrowed from others, including the brewing traditions, two hops stand out. They are the most widely grown aroma varieties in the United States: Willamette and Cascade. Both are cultivars of Fuggle.

Perhaps because of the popularity of Sierra Nevada Pale Ale, both an American beer style and an American hop cultivar have become the standard for the western region of the country. Sierra Nevada uses ample Cascade hops in the boil for its pale ale, and the Sierra Nevada Pale Ale has become the exemplar of the American pale ale style.

An American pale ale might be judged closest to style if it has ample Cascade aroma, while Goldings would be the hop of choice for an English ale. German beers most often employ noble hops such as Saaz, Hallertauer, and Tettnanger.

Hops are available in domestic and imported varieties, for instance German Hallertauer and American-grown Hallertauer. While these are from the same breeding stock, the cultivars vary because of harvest year variances, soil conditions in the regions, and climatic conditions.

Many of the world’s great hops are grown in the United States and have been grown from cuttings or seed from the original stock. There are also cultivars of European origin that have been selectively bred in the United States to create a new hop. American Hallertauer derivatives include Liberty, Mt. Hood, Crystal, and Ultra. These might have aroma characteristics similar to the German Hallertauer, but essential oils and alpha-acid contents vary from the original cultivar.

Some of these hops can replace Hallertauer suitably, though many brewers argue that there is nothing like the original.

Making a Choice
Characteristics to look for when selecting a hop cultivar are alpha acid content, co-humulone content, use as bittering or aroma, beer style associations and traditions, aroma and flavor characteristics, and pedigree.

Alpha-acid content has a direct correlation to the bitterness expected of a hop. The higher the alpha-acid percentage the greater the bitterness. Alpha acids are derived from co-humulone, ad-humulone, and humulone. Co-humulone is believed to add a harsh, astringent bitterness to beer as well as adversely affecting head retention. In bittering hops with high alpha acid content, look for varieties with the lowest co-humulone content. Co-humulone percentages vary from the teens to the forties, and lower percentages produce beers with a smoother, rounder profile and without harsh astringency.

Hops are classified as either bittering or aroma hops. Some are considered dual-purpose hops. Bittering hops have a higher alpha-acid content than aroma varieties. Hops with high alpha-acid content often make poor aroma hops. It can be difficult to get satisfactory aroma without overbittering the beer. Also, the aroma characteristics tend to be unstable. The beer might change in character over time, and the aromatic qualities might degrade.

Dual-purpose hops generally have a median alpha-acid range, making them satisfactory for bittering. These varieties generally make better aroma hops than the high-alpha hops, because it is easier to produce a fine aroma in the beer without overbittering.

Aromatic hops generally contain lower alpha-acid percentages. Essential oils produce the flavor and aroma of hops and are contained in the yellow to golden pollen of the lupulin glands. Myrcene, humulene, caryophyllene, and farnesene are the main components of essential oils. Ratios of these oils determine the quality and type of aroma and flavor of the hop.

When examining a hop for aroma, crush the flowers in the palm of your hand and rub them vigorously to release these oils. An accurate estimate of the aroma can’t be made without this rough handling. Aromas range from citrus to perfume and from floral to grassy. Some smell vegetal while others smell quite sweet. Get to know the aroma of the hop well before it goes into your brew.

Flavor and aroma characteristics vary widely from hop to hop. Try blending hops to see which aromas blend well and which varieties clash. Breweries most often use a blend of hops rather than just one variety. Keep in mind that not all hops will blend well. That sweet character of one blended with the spicy character of another might not meld harmoniously, and this where the brewer’s art comes into play. Finding the right combinations is often a matter of trial and error.

Hops that complement one another often run along pedigree lines. You might find that noble hops will blend well together, but a mix of German nobles and sweet English Goldings clashes. You might also find that the character of one hop brings out the character of another, much as salt brings out the flavor of garlic in cooking.

Data on pedigree is important to check when brewing with an unfamiliar hop. The pedigree gives some generalization of the flavor and aroma qualities to expect. If the pedigree is similar to a hop you are familiar with, generally you can expect a similar profile from the new hop. This is often but not always the case. Sometimes the genetic origin is similar, but selective breeding has changed the character of the hop.

Often, new hops are developed for ease of harvest, packaging qualities, resistance to plant diseases, and increased yield per acre. The hope is to develop a variety with characteristics similar to the original but with greater profitability for the farmer and the hop processor. This is one of the reasons that a multitude of similar cultivars is available on the market all with similar qualities. Still, no two varieties are the same, and it is best to compare side by side.

When selecting a hop variety, consider the goals you’ve set for your brew. Do you wish to emulate a style or a particular beer, or are you out to create something totally unique? When trying to duplicate a style of beer, use the hops associated with the style and region of the beer. Saaz hops epitomize lagers but might seem a bit out of place in a pale ale. Because regional cultivars in help to define beer styles, so select the most authentic ingredients to best duplicate a style.

Choose the hop you like the best and experiment. Many breweries have brewed single-hop beers to feature the characteristics of a particular favored hop. There is no better way to become intimately familiar with a variety. By brewing with a single hop, you easily can learn the flavor and aroma qualities of a variety without the characteristics of another variety interfering. While hop blending is more common in brewing, single-hop brews have become more popular and are certain to give the brewer a more thorough hop education.

Choosing Hops
When selecting whole hops, you should take a look at the cones to assess their freshness and condition. The European Hop Producers Commission has a standard test for hops, awarding up up to 100 points are awarded for value enhancing properties, and deducting up to 30 points for value decreasing properties. Even if you don’t bring a calculator to the homebrew store and plot out each of the available hops’ score, you can use their guidelines to pick the best hops available. The assesment includes:

  • Crop purity (1 to 5 positive points): The hops should be free from stems, leaves, and contaminants.
  • Dryness (1 to 5 positive points): In squeezing the hops together the cones should not stick together or lose their leaves; if too wet the hops become dark brown, odor is musty, and mold develops.
  • Color and gloss (1 to 15 positive points): The color should be yellowish-green and the cones should have a silky sheen. Grey-green = unripe; yellowish-red = over-ripe (oxidation).
  • Cone shape (1 to 15 positive points): Uniformly large, closed cones are favored.
  • Lupulin (1 to 30 positive points): There should be as many lupulin glands as possible and they should appear yellow to golden yellow, shiny, and sticky. Lupulin is naturally the most significant feature of the hop any brewer looks for.
  • Aroma (1 to 30 positive points): The aroma should be clean, very fine, and strongly persistent. Each varietal type has its own aroma that can be detected. Off-odors include smoky, burned, onion, garlic, hay-like, grassy, straw-like, cheesy, and sulfury.
  • Diseases, damage, seeds (1 to 15 minus points): This includes damage because of blackness (aphids), browning (spider mite or wind damage), reddish tips (strig midge), cone death and loss of bracts, bracteoles, and seed formation.
  • Defective handling (1 to 15 minus points): Includes brown or burned hops as a result of high drying temperatures, deterioration due to high moisture content, and off-odors.

After the overall evaluation you can classify the hops as follows:
Less than 60 points = poor
60 to 66 points = average
67 to 73 points = good
74 to 79 points = very good
More than 80 points = premium

Issue: November 1999