Beer Styles: The Ingredients (Part Two: Hops)
In the second part of this series on the ingredients of beer, we will examine hops, the additive that provides an assortment of flavours to beer.
By David Nuttall on Mar. 09, 2017
Of the four main ingredients in beer, hops came late to the party. In fact, it is entirely possible to make a beer without hops at all; which can’t be said of the other three ingredients. However, there is no doubt hops had been used in brewing long before brewers knew what their properties were or how to properly manipulate their usage in a recipe.
Hops were first documented in Germany around 736 A.D., but it took about another 700 years for them to be accepted in Britain. Before hops became the common bittering agent in beer, many varieties of herbs, spices, and flowers were used. Anything from dandelions, marigold, heather, ivy to spruce and pine tips or needles, tree bark, berries, kelp, bog myrtle and more were ground into a mixture called gruit. This combination of flora was dominant in beer recipes until the 16th century, when hops began to be cultivated in England and became mandated in Germany by the Reinheitsgebot (German Beer Purity Law) of 1516. It was also discovered that hops acted as a preservative to prevent spoilage, an important attribute for long voyages in the Age of Discovery. They were first planted by the Dutch and English in North America in the 17th Century, but it wasn’t until the late 1800s that the hop fields of Washington and Oregon were started. Today, hops are grown in several countries, but the main suppliers to the world‘s breweries are still Germany, United States, Czech Republic, England and China, although very few of the latter’s hops are exported.
Hops are the female flower of the Humulus lupulus plant, a relative to cannabis and hemp. Looking somewhat like a tiny pine cone, it is within the lupulin glands that the necessary resins and oils reside. It’s the alpha acids of the resin, expressed in percentage weight, that contain the characteristics of bitterness, flavour and aroma unique to each hop variety. Alpha acids contain humulone, cohumulone and adhumulone, which are present in different amounts in each hop. They all get isomerized during the boil. The plant itself is a vine that grows actively in the right climate, as much as twenty feet in a season. Because it can topple over on itself, the vines are often attached to trellises, strings or poles for support on lands called hop farms, yards, gardens, or fields.
The harvest is in late summer, as the flowers are picked and taken to an oast or hop house for drying. When ready, they are either kept as whole hops, pressed into bales, compressed into plugs or pellets, or condensed into extract; all forms are used by breweries. Since the early 20th century, cross breeding has become popular in order to isolate various qualities of certain hops. This has accelerated since the 1970s as programs at Washington State and Oregon State Universities lead the way with the introduction of the new hop varieties which have become the calling card of the American craft beer explosion.
While there are a couple of hundred varieties of hops used in making beer, they are commonly divided into either aroma or bittering hops. Some can be used for both, and are called dual purpose hops. Aroma hops tend to be lower in alpha acids, and the European versions are often called noble hops, for their delicate bittering properties, and attractive aroma characteristics. Amongst the German varieties are Tettnanger, Splat, and Hallertauer; the English have Golding and Fuggle, the Czechs grow Saaz and the Americans produce Cascade, Willamette and Liberty. These varieties have 3-15% alpha acid, and are generally added late in the boil (i.e. the final 10 minutes) for aroma or last 30 minutes for flavour, in order to prevent evaporation of the essential oils.
Bittering hops range from 8-21% alpha acid and can be added any time in the boil, but more bitterness is extracted the longer it remains in the kettle; the general range is 30 minutes up to as much as 120 minutes. Varieties of this type include Admiral, Columbus, Nugget, Magnum and Bravo.
Dual purpose hops are Simcoe, Northern Brewer, Centennial, Chinook, and Nelson Sauvin. They are added to the boil for anywhere from 10-90 minutes depending on whether they are used more for flavour or aroma. They have the largest range of alpha acid; from 3-23%. Brewmasters may put in the same hop at different times or may put in multiple hop castings to achieve the end result they want.
The new hops developed in the last few decades have kick-started many beer varieties, most notably in the IPA category. The British IPA has been around for a couple of hundred years, but the American IPA was introduced only about 40 years ago. Since then, craft brewers have upped the IBUs with Double and Triple IPAs, and even the Belgians have joined the fray by using American hops in their IPAs. New hops have shown up in countless other beer varieties, and with more being developed every year, don’t expect any kind of slowdown.
Countries like Australia and New Zealand are also growing and exporting new hop varieties which have additional characteristics. Hops balance out the sweetness provided by the malt, but they also impart a variety of flavours and aromas to the final beer. This may range from evergreen or earthy notes through spicy and herbal zest to fruity and citrusy. Hops are now being used to achieve flavour profiles never before attempted in historical beer styles. Coupled with the increased use of adjuncts such as fruit, vegetables, herbs, and spices (gee, what goes around comes around…) and the result is there are now more beer choices than ever before.
So when you drink your next beer, see if you can smell and taste the part of the beer’s attributes imparted by the hops. More craft beers now are highlighting the hops, not something you will find with most Big Brewery beers. As you become familiar with them, you may even start to recognize their unique characteristics. Since more breweries are now divulging what ingredients they actually put in their beers, today’s consumer has a greater opportunity to become aware of their drinking options. In the next part of this series we will review water, the largest component of beer, but easily the most overlooked.
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