Lager Style Beers

Lager:

Lager, on the other hand, is fermented using Saccharomyces uvarum. It was first used for brewing in Bavaria in the Renaissance, one of the first species to hitch a ride from the American continents to Europe during the discovery and exploration of the western hemisphere.

This yeast isn’t so much bottom fermenting as much as that it doesn’t rise to the top as an ale yeast will before settling to the bottom as fermentation winds down. Because the yeast didn’t really show up at the top of the fermentation vessel, it was probably assumed to be bottom fermenting instead, as early fermentation vessels were constructed of materials that made it difficult to see the bottom of the vessel.

Compared to ale yeast, it is a much more fragile yeast, which requires more specific conditions to thrive. However, this means it can produce different outcomes than ale yeast.

This fragility means the yeast can’t sporulate, or form a cyst of a few cells with a protective wall at cold temperatures, which means this yeast can remain active at temperatures below 39°F. It also attenuates sugars more slowly, causing the brewing process to move more slowly. It has a lower tolerance to alcohol and has the ability to ferment mebilose, a sugar that is not fermented by top-fermenting yeasts. These last three features allow more sugar to remain in the mix, creating a smoother, sweeter beer.