What type of yeast is typically used for brewing lager?

Lager is primarily brewed using bottom fermenting yeast, specifically strains of Saccharomyces pastorianus. This type of yeast ferments at cooler temperatures, typically between 45°F and 55°F, which is essential for developing the clean and crisp flavor profile characteristic of lagers. The yeast settles at the bottom of the fermentation vessel during fermentation, hence the name "bottom fermenting." This fermentation process leads to a smooth taste and helps prevent the production of certain esters and phenols that can contribute to a fruity or spicy flavor, which is more common in ales brewed with top fermenting yeast.

While other types of yeast exist, such as top fermenting strains used for ales, wild yeast, and brewer's yeast (which can refer to both types), they do not provide the same properties and outcomes required for traditional lager brewing. The unique qualities of bottom fermenting yeast make it the preferred choice for producing this style of beer.