Welcome to The Ingredient, a four part series on the Frankenmuth Brewery blog that looks at the basic ingredients that make up Michigan craft beer. In the fourth and final installment, we discuss the value of yeast in the brewing process.
When you think of beer, yeast is probably not the first word that comes to mind. Water is natural, grain is necessary, and hops are intriguing, but what does yeast do? With the growing popularity of home brewing and craft beer, in Michigan and all across the country, more people than ever are interested in finding out just what the various ingredients of beer really bring to the table. Yeast is an interesting one because it’s a microorganism, which means it’s alive. This ingredient has been a hugely useful component of brewing since ancient times, so today we’ll learn all about it.
Some consider yeast to be the most important beer ingredient of them all. This is because it is the yeast that provides the alcoholic content. More specifically, the reaction between the yeast and the sugars and carbohydrates is what leads to the formation of alcohol and carbon dioxide. It is this step in the process that turns the wort concoction into the Michigan craft beer you know and love!
Yeast is also known as brewer’s yeast, although other species are used for brewing as well. There are two main types of yeast used in brewing: top-fermenting, also known as ale, baker’s, and budding yeast, and bottom-fermenting. The strain of the species used for top-fermenting is called Saccharomyces cerevisiae, while bottom—fermenting is done with Saccharomyces uvarum.
Top and bottom refer to where the yeast settles, so it makes sense that top-fermenting tends to have a darker color. The beers you know as ales are brewed with this kind of yeast. Hefeweizens, IPAs, porters, stouts, and blondes are some of the other most well-known varieties of top-fermenting brewed beer that you’ll find all across breweries in Michigan.
The settling of the material at the bottom naturally results in a clear beer. Lagers are made with bottom-fermenting yeast. Pilsners, like the version of this style you’ll find at our brewery in Michigan, are brewed with bottom-fermenting yeast that results in an even paler color than other lagers. Other popular lager styles are bocks, Helles, and Munich-style Dunkels.
What happens during brewing is that the yeast is distributed throughout the beer while it is fermenting, and then the settling to top or bottom occurs. There are three types of fermentation: warm, cool, and wild. Lagers are fermented at cooler temperatures (50 °F) while top-fermenting beers do so at warmer temperatures (59 and 68 °F, and sometimes as high as 75 °F).
The third type, known as wild or spontaneous, is how lambic beers are brewed. Most other beers are brewed using cultivated strains of brewer’s yeasts crafted with careful deliberation. This style of fermentation, traditionally Belgian, is spontaneously created by exposure to the wild yeasts and bacteria of the region, resulting in a uniquely distinct dry and cidery flavor.
As our series on the ingredients of beer draws to a close, enjoy this especially fun fact about beer yeast. Thanks to the importance of S. cerevisiae to the brewing of craft beer, it has been recognized by the state of Oregon as the official state microbe thanks to the impact that craft brewing has had on the state’s economy! Is beer yeast the coolest microorganism? The state of Oregon thought so, and we here in Michigan tend to agree!
As the source of fermentation, beer yeast is as vital to the brewing process as all the other main ingredients. Although certain flowers, herbs, and spices are sometimes added to certain styles to enhance flavor, the big four of water, grain, hops, and yeast are proven to work together perfectly in creating the Michigan craft beer beverages that we all know and love. Brewing is truly an art form. Once you learn all about the complexities of the ingredients, it’s no secret why. Enjoy the taste of beer from breweries in Michigan even more when you appreciate the finesse that goes into each and every batch!