The Science of Beer
Buffalo is in the midst of a craft beer movement that has swept across the nation. New breweries are being opened at an increasing rate. A plethora of imported beer offerings from across the world are now distributed across Western New York. Homebrewing is on the rise and people are reconstructing their favorite beer in a garage or basement. People are flocking to beer tastings and festivals. Beer geeks stand in long lines for the chance of obtaining a rare beer produced only once a year.
Concomitant with the rise of craft beer popularity is an increase in curiosity about beer. People are asking questions about the science of beer. How is beer made?What ingredients are used? Why does some beer taste bitter and some beer taste sweet? What factors contribute to the color of a beer? How are yeast used in brewing?
There are four main ingredients in beer: water, grains, hops, and yeast. And yet endless combinations of these four ingredients are all that is needed to produce the majority of beers in the world. Of course brewers are famous for being experimental with these ingredients and pushing beer style boundaries to new limits. Brewing is about creating a new beer from a standard set of tools. The four main ingredients in beer are:
Water: 85-95% of most beers are water. Factors such as water hardness and chemicals present in unfiltered water can impact beer quality. However, modern technology provides sophisticated filtration devices that can eliminate most of the differences in regional water quality. Still, a brewery may wish to alter their water as desired to produce a unique taste.
Grains: Malts are cereal grains that have been steeped, germinated, and dried. Malted grains ultimately provide the source of fuel for yeast growth—sugars. Sugars are extracted during the brewing process from a variety of grains. The most commonly used grain in brewing is barley, but other grain adjuncts such as wheat, rice, and corn may also be used in brewing.
Hops: Much of the perceived bitterness in beer is due to the presence of oils found in hops, known as Humulus lupulus. Mature female hops plants contain resins and oils in their seed cones. As heat is applied during the brewing process, some of these chemicals are converted into other chemicals that are responsible for perceived bitterness in beer.
Yeast: Yeast are a type of fungus that boast the ability to metabolize sugar and produce alcohol. There are many different kinds of yeast, known as strains, that possess differences in way sugar is metabolized. These differences can impart different flavors in beer. Ale yeast and lager yeast ferment at different optimal temperatures. Brewers must make the important decision of which yeast to use when crafting beer. Yeast are living organisms that must be maintained with extreme care in the brewery in order to prevent contamination of beer. Organisms other than yeast, such as bacteria that produce lactic acid, may also be used in conjunction or in place of yeast to provide a unique flavor beer profile.
Holistically, beer is more than just water, grains, hops, and yeast. Beer is a multi-sensory phenomenon, and people who craft and consume beer have become increasingly curious about the factors that determine the perceived quality of beer. Crafting an exceptional beer is an art form ultimately dictated by science. A world-class beer is an ideal blend of chemistry, microbiology, psychology, and many other “-ology” disciplines.
In fact, “beerology” is the perfect word to describe the study of the science of beer. This year, “Beerology: It’s Science on Tap!” presented by the Buffalo Museum of Science on Saturday, April 18, 2015 is (not surpringly) sold out yet again. Thirsty crowds will quench their curiosity with beer and cider samples from over 25 different vendors. Presenters will display homebrewing skills and discuss science-related beer topics. Beerology, and many other events taking place across Western New York, accentuate the interest that people have in exploring beer science. People want to know more about the beer they drink.
The next few installments of this column will explore various “beerology” topics, such as:
Chemicals: What chemicals are found in beer? What makes beer taste bitter? What chemicals can cause off-flavors like skunked beer? Of what importance are the chemicals found in hop oils?
Yeast: Why do brewers use different yeast for different beers? What makes a beer taste sour?
Appearance: What is the science behind foam in beer? Why are some beers dark black and other beers light golden in color?
“Beerology: It’s Science on Tap!” is a great place to start exploring the science of beer. This column will further explore beerology topics and clarify the science of beer.
(This article was originally featured in Artvoice on 4/9/15)