How to Choose Yeast for Your Home-Brewed Beer

The type of yeast used in brewing beer will define the character of the beer and create your unique signature. With more than 500 various strains of yeast available, the task of choosing one can be somewhat daunting, but if you know some basic qualities of yeast it will help you in choosing the right ones. Things to consider when choosing yeasts are flocculation, flavor and aroma, production of fermentation bi-products, attenuation, and rate of fermentation.

Flocculation refers to the yeast’s ability to clump and settle at the end of fermentation when the sugars have been converted into ethyl alcohol. Flocculation will help determine the clarity of the beer and is classified as low, medium, or high. Many American and English ale yeasts have medium to high flocculation while most lager yeasts have low to medium flocculation. Low flocculates will leave a bit of yeast in the beer after fermentation.

Very important traits to consider when choosing a yeast for your home-brew are flavor and aroma, which are determined by the levels of bi-products the yeast creates. Many fruity beers contain higher levels of esters. Diacetyl is a bi-product that gives the beer a buttery taste, which is generally not a desirable quality in a beer, especially in English ales. Fusel alcohols tend to have spicy, wine-like qualities. Playing around with flavor and aroma can be a fun experience, and many seasoned brewers had to play quite a bit before they found the exact recipe they were looking for. Researching various beer types will be beneficial to you as you search for your signature recipe. For instance, yeasts with clove or banana flavors and aromas are generally not found in American or German wheat beers, but they are found in many German weizens. Belgian wit yeast is similar to German yeasts but results in a crisper and more tart flavor.

The degree of attenuation is also a very important factor to consider when choosing a yeast as it affects the flavor of the final product. Degree of attenuation refers to the process of sugars in the wort transforming into alcohol and carbon dioxide throughout the fermentation process. The degree of attenuation affects the final gravity of a certain beer and is classified as low, medium, or high. It also can be listed as a percentage. A lower degree of attenuation, such as 60%, will result in sweeter beer with a higher gravity because more unfermented sugars will remain in the beer.

Rate of fermentation can be looked at when choosing a yeast, but it isn’t as much of a concern as other factors we have mentioned and fermentation rates are difficult to find. Generally, slower fermenters are lower attenuators and produce maltier beer.

Many home-brewers choose a yeast strain by considering the name the manufacturer gave it. For instance, if you wish to create an American Ale you may choose a type of American ale yeast. Don’t be afraid to play around with different recipes a bit to come up with a final product you are happy with. In addition, don’t be surprised if it takes awhile to come up with a beer that tastes just right. Brewing your own beer is an enjoyable process so, first and foremost, have fun!