Up to this point, we have looked at the role water and malted grains play in the making of beer. For thousands of years this duo has been crucial in creating fermented beverages that people have enjoyed across cultural lines. However, a beverage made solely of grains and water is much too often overly sweet and lacks balance to make it enjoyable. This is where the presence of bitterness comes into play, and for hundreds of years brewers have utilized hops to accomplish this.
The presence of bitterness provides a needed balance, restraining the residual sweetness of the grains allowing for our palates to want to come back for another sip. For centuries brewers turned to a variety of plants and herbs to provide this bitterness, though within the beer family of beverages these hop-less beverages are typically referred to as gruit. Over the centuries brewers have used a plethora of plants while brewing, some with undesirable side effects that could make people ill, but in the early part of the last millennium early brewers discovered that hops proved the perfect plant to provide a balancing bitterness. Over the next few centuries the hops grew in dominance and quickly became a crucial brewing crop throughout the brewing nations of Europe.
A member of the Cannabaceae family, cousin to cannabis, hops grow on bines that can reach over twenty feet when strung up on an overhead trellis. Resembling bright green leafy pine cones, Hops are full of a variety of chemical compounds that brewers need to add aroma and bitterness to the beer they produce. The compounds occur in the lupulin glands in each cone which contain oils and acids that impart aroma and flavour.
When boiled for an extended period of time, the acids break down into a bittering compound. Each hop variety has a differing amount of acids and brewers carefully select which variety they use, and during the boiling of the wort they add these hops. With hops added early in the boiling process, the acids have a longer time to break down and impart more bitterness. Hops added later in the boil leave more flavour and aroma as the acids have less time to break down and the oils from the cone are retained and boiled off in the brewer’s kettle.
The location of where the hops are grown plays a large role in the oils that develop in each variety and this impacts the aroma. Classic brewing hops from continental Europe are often herbal, grassy and spicy. Hops grown in the United Kingdom can have the aroma of candied citrus, leafy tea and warm woodsy aromas. Newer varieties from North America often smell of zesty citrus, resiny pine and passionfruit; while hops cultivated in Australia and New Zealand smell of white wine, peach and tropical fruit.
Next we will look at the single celled organism that is truly the key element to making beer: yeast.