Lager yeast and ale yeast (Saccharomyces)
Term from the Brauwerkstatt brewing glossary, category “Fermentation and yeast”.
Explanation
Beer yeasts belong to the genus Saccharomyces. Ale yeast (Saccharomyces cerevisiae) is top-fermenting, works at 15–24 °C (59–75 °F) and produces more fruity esters. Lager yeast (Saccharomyces pastorianus) is bottom-fermenting, works at 8–13 °C (46–55 °F) and gives a clean, clear flavour. It arose centuries ago from a cross between ale yeast and a cold-tolerant wild yeast.
Test your knowledge
What does the name of brewer’s yeast, Saccharomyces cerevisiae, mean?
- Bread fungus of the north
- Fermenting fungus of the monks
- Sugar fungus of beer
Show answer
Correct: Sugar fungus of beer. “Saccharomyces” means sugar fungus, and “cerevisiae” comes from the Latin “cerevisia” for beer.
What did lager yeast originate from?
- A cross between ale yeast and a cold-tolerant wild yeast
- Baker’s yeast that was frozen
- Wine yeast from Bohemia
Show answer
Correct: A cross between ale yeast and a cold-tolerant wild yeast. Saccharomyces pastorianus is a hybrid of Saccharomyces cerevisiae and a cold-tolerant wild yeast.