People love beer. This is understandable. The beverage has roots in early civilization and is even credited as the fuel that built the pyramids. The discarded, soaked grains that early humans found to have fun and un-inhibiting properties are now known to have simply been fermented with wild yeast. The rest, as they say, is history.
Yeast is an extremely important part of the brewing process.
The fungi turns what would be an average syrupy, sugary drink into what we all know as beer. In very, very unscientific terms yeast eats sugar molecules and excretes alcohol as a byproduct. A living organism, yeast reproduces exponentially and works tirelessly to provide humanity (and a few other lucky fauna) with an enjoyable, tasty adult beverage.
There are two types of yeast found in the brewing process. First is ale, or top fermenting, yeast. This culture thrives in warmer temperatures and does its work at the top of the liquid, forming a foamy cap over the fermenting beer. This yeast type is used to brew anything from pale ales to imperial stouts.
The second type is lager, or bottom, fermenting yeast. This fungi is only active in colder temperatures and sits at the bottom of the fermenter. Bottom fermenting yeast work slowly and methodically, as lagers generally take a few months longer than ales to finish fermentation. This yeast type is used to brew anything from pilsners to marzens.
Alcohol isn’t the only byproduct of yeast. Different strains of yeast will impart varied and unique flavors and aromas into each beer. Why can German hefeweizens have a tinge of banana and Belgian tripels blossom a bouquet of clove? Yeast!
Making beer is similar to making bread. The term liquid bread for (early) beer is an apt one. Just as yeast plays a role in taking a lump of dough and raising it into a fluffy loaf of bread, it also takes viscous liquid and turns it into the wide array of beer we are able to enjoy today.
Hopefully this brief tutorial took some of the mystique out yeast. And perhaps even armed you with the skills to begin to notice, and even appreciate, the nuances provided by our friendly little micro-organisms.
The Fun Guy of Fungi
Lord of Libations