the amount of solid material in a given
volume and making the bread or cake less
dense, more light and tender.
Yeasts
Humans have been eating raised breads for
6,000 years, but it wasn’t until the
investigations of Louis Pasteur 150 years ago
that we began to understand the nature of the
leavening process. The key is the gas-
producing metabolism of a particular class of
fungus, the yeasts. The word “yeast,”
however, is as old as the language, and first
meant the froth or sediment of a fermenting
liquid that could be used to leaven bread.
Food Words: Leavening and Yeast
Leavening comes from an Indo-European
root meaning “light, having little weight.”
Related words from the same root include
levity, lever, relieve, and lung. Yeast comes