Definition

Noun A specific strain of brewer's yeast (Saccharomyces pastorianus) used in the production of lager beers. This yeast ferments at cooler temperatures and settles to the bottom of the fermentation vessel, a process known as bottom fermentation.

Usage

This term is a technical compound noun used specifically in the context of brewing and microbiology. It refers to the biological agent responsible for a particular fermentation style.

Examples

• The distinct clean taste of a pilsner is achieved using bottom fermenting yeast.
• Brewers must carefully control the temperature when working with bottom fermenting yeast.
• Bottom fermenting yeast is essential for producing traditional lager beers.

Advanced Usage

• The term is often contrasted with "top fermenting yeast" (), which is used for ales and ferments at warmer temperatures, rising to the top.
• It can be part of discussions on beer history, as the use of this yeast strain is a defining characteristic of lager brewing, which originated in Central Europe.

Variants and Related Words

• Bottom fermentation (n): The fermentation process associated with this yeast, occurring at colder temperatures (7–15°C or 45–59°F).
• Lager yeast (n): A common synonym for bottom fermenting yeast.
• (n): The scientific taxonomic name for this yeast species.

Synonyms

• Lager yeast

Notes on Meaning

This is a highly specialized term with one primary meaning in brewing science. It does not have general idiomatic or phrasal verb uses. Its meaning is directly tied to its function in the beer production process.

Noun

1. brewer's yeast used in bottom fermentation of lager