Yeast » Wyeast


 

Brewing yeasts may be classed as "top cropping" and "bottom cropping". Top cropping yeasts are so called because they form a foam at the top of the wort during fermentation. Bottom cropping yeasts are typically used to produce lager-type beers, though they can also produce ale-type beers. These yeasts ferment more sugars, creating a dryer beer, and grow well at low temperatures.