THE USE OF HOPS

 

Only a few ingredients are needed to make beer. Most beers are brewed from barley malt, unmalted grain such as corn or rice, hops, yeast, and water. The brewing value of hops is found in the unique flavors and other properties which come from resins and oils inside the lupulin glands.

Barley malt is ground and mixed with other grains to "fuel" the fermentation process. These ingredients are mixed with water and mashed so that the grain starches are converted to smaller carbohydrates, mostly fermentable sugars. This mash is separated into a clear liquid called "wort" which contains the sugars and other grain-derived components, and the non-soluble spent grains.

The wort and hops are boiled in the brew kettle to extract the hop resins and oils. The boiled out spent hops are usually added to the spent grain and sold as high quality livestock feed. The wort is clarified and cooled, and yeast is added. After several weeks of fermentation and final clarification, beer is produced.

Glossary of Terms AROMA

Much is spoken of the quality and intensity of dried hop aroma. These are strong varietal characteristics. There appears to be a general relationship between the type and heaviness of a hop aroma and the flavor and aromatic properties of beer.

BETA ACID

A soft resin component, beta-acids are not bitter in the natural or isomerized form. Some of the oxidation products do provide bitterness, and the beta-acids can be chemically transformed into light stable bittering forms.

CO-HUMULONE

The alpha acids exist in three analogous forms, humulone, ad-humulone, and cohumulone; and the proportions of these analogues vary markedly with variety. Varieties with relatively low co-humulone levels are strongly favored.

CONE STRUCTURE

There are certain physical properties of hop cones while unimportant in the brewing process, are strongly characteristic of a particular variety. Light loose cones are much more prone to shatter during harvesting while heavy dense cones pick beautifully as they roll well and hang together.

DISEASE REACTION

Varieties can display a wide range of reaction to various hop diseases. Of great importance in the U.S. are the fungal disease downy mildew and the viral disease ring-spot.

GROWTH HABIT

Hop varieties vary widely in structural aspects such as general vigor, lateral length, and the overall vine structure. These type of characteristics can make a variety more or less easy to pick and handle.

LUPULIN

Hop lupulin may vary in color from pale yellow to an intense golden color. It is not known if lupulin color affects brewing performance, but it is a fairly strong characteristic of a variety. It is certain that the bitter hops have much greater quantities of lupulin than the aromatic types.

MATURITY

This is a statement of the time in the hop harvest season at which the particular variety reaches optimal maturity. Harvesting in the United States occurs from about August 20 to September 20.

MYRCENE, HUMULENE, CARYOPHYLLENE, FARNSENE

The four major components of the essential oils and between them they account for about 60-80% of the essential oil of most varieties. The compounds are all highly volatile hydrocarbons; and during boiling of the wort, most if not all of them, are driven off and contribute little to hop flavor and aroma in beer.

PEDIGREE

Brief remarks about the ancestry of a variety. In the case of very old varieties like Saaz or Hallertau, there is no ancestral information. We know only that this particular varietal type was selected over many years by growers and brewers in a particular area. More modern varieties can often be traced back through two to three generations of crosses often involving other known hop varieties. It is important to note that the qualities of a hop variety are only partly determined by the genes it receives.

PICKABILITY

This is another characteristic which is of direct concern to both grower and brewer. If a hop is known to pick well, one can expect a good clean sample. If a hop is difficult to pick, one is more likely to see shattered cones and a higher proportion of leaf and stem in a sample.

STORAGE

Oxidation of alpha acids removes their ability to be isomerized to the required bitter isomers. In comparable circumstances, some varieties lose a greater proportion of their alpha acids to oxidation than others do. Cold storage and anaerobic conditions can delay oxidation. Some oxidation of essential oil components is necessary to produce compounds thought to be important in beer flavors, so controlled aging is important for hops required for both bittering and aromatic properties.

TOTAL OIL

This characteristic varies widely with seasons, varieties, and growths from 0.5 mls to about 3 mls per 100 g of hops. While the soft resin are responsible for providing the bitterness of a beer, the quantity and composition of the essential oils are responsible for the amount and quality of hop flavor and aroma in beer. YIELD

This is the kiln dry weight of hops normally produced by a variety in commercial production in the U.S. On an average, the aromatic types tend to be lower yielding and more highly priced than the bitter types.

HOPS IN BEER By Paul D. Knight

The use of hops in beer most likely began when some ancient cave brewer, in an effort to gain a competitive edge, started experimenting with "additives" to his product. The hops grew wild, as did the brewer, the barley and the yeast. Some degree of variability in the product was no doubt acceptable.

The use of hops probably started before recorded history. It is known that the Babylon and Egyptian people used hops and other aro-matic and spicy plants to improve the palatability of their brewing efforts.

Germans are often identified with hops and beer, but from a historical perspective, this is of recent practice. The first documented evidence of hop yards in Germany dates back to the year 736, to a monastery in Bavaria.

The early brewers, especially those on the cutting edge of technology, discovered that the beer containing hops had better keeping qualities than their unhopped products. The practice then began of adding greater quantities of hops to beer depending on the season of year and expected storage time. More hops equaled greater storage life. The reason for this was not known and not important; the results were important.

Hop production in America followed closely the settlement of the first colonies in the New England areas. Early American brewers used wild hops, but the cultivation of hops in the old world had progressed to "industry status" and soon moved to the new world. After growing hops in New England and Virginia, the center of hop production moved to New York State by the middle 1800s. Problems with powdery mildew practically wiped out the production of hops in New York about 1909. The region revived again around 1920 with the discovery of sulfur-based fungicides only to be devastated again in the late 1920s by downy mildew.

Starting about 1850 the hop industry in the Western states of Washington, Oregon and California began to develop and eventually became one of the major regions of the world. In recent years, California and Western Washington hop production has ceased. Oregon and Idaho still account for 25-30% of U.S. production while the Yakima Valley of Washington totals 70-75%. The total U.S. production accounts for nearly 30% of the world hop crop.

Brewers no longer rely on the antiseptic properties of hops for microbiological control and, in general, the modern consumer prefers a lighter and lesser hopped beer. The growing and processing of hops has become a highly scientific endeavor as has the brewing of beer. Hop usage in beer is deeply ingrained and is considered one of the more vital ingredients. Beer without hops is unthinkable. Or, for that matter, so are hops without beer!