Cream yeast (see separate entry on how cream yeast is grown) is pressed through filters to form a more solid matter, which is then compressed into small cakes about 1/2 ounce (15 g), or larger bricks about the size of a pound of butter. Most of us will just see the small cakes, wrapped in foil, in chillers at our supermarkets. The cakes should be firm and moist, easy to crumble and putty-coloured. Any that are dry when you get them home, take back, because stale yeast can make your bread taste sour.
Purists sniff at using dried yeasts, and will only use fresh. They say that it makes supple doughs with a subtle fragrance. And if you’re such a purist, I don’t blame you: I mean, I’m sure you’ve also ground your own flour and churned your own butter, so of course you have every right to be picky.
Generally, 1 cake is used for 1 loaf of bread. Fresh yeast has no “lag” phase, in which it needs to come back to life in water. It is live.
See main entry on Yeast for how Yeast Cream is grown.
Cooking Tips
Not for use in bread machines; there are numerous reports that it doesn’t last well through the rigorous machine kneading.
Substitutes
Any form of dry yeast, or your own starter.
Equivalents
1 cake of 1/2 ounce (15 g) = 1 packet / 1 tablespoon of dry yeast
5 g fresh yeast = 1 teaspoon dry yeast
To convert fresh yeast measures to measures for active dry yeast, multiply x .4 (Rose Levy Beranbaum, in her Bread Bible book, says multiply by .32)
Storage Hints
Will keep refrigerated for 10 to 20 days. To freeze, wrap well, then wrap again — it mustn’t dry out. Thaw overnight in refrigerator. If your frozen fresh yeast looks dry, discard it. Generally, it’s good for about 3 months in the freezer.
History Notes
Compressed fresh yeast cakes became commercially available in the 1870s in America. Before then, people used home-made starters for their bread. Dried yeast was developed during the Second World War.