Dear Peggy: I found an old recipe that uses a large cake of yeast. I remember long ago that grocery stores carried two sizes of cake yeast but can't find it anywhere now. Can you help me? —L.S., Ocala, Florida
Years ago, yeast was sold as cake yeast, also called "compressed" or "fresh yeast." Now, the crumbly square is not widely available, though it can be found in some supermarkets and specialty food stores. Some die-hard bakers still prefer cake yeast, which is quite potent and adds a wonderful yeasty flavor. But it's very perishable, so it must be refrigerated and used quickly, which is one reason active dry yeast has become so popular.
Cake yeast comes in two sizes—.6-ounce and 2-ounce packages. Whenever substituting, use about 2-1/4 teaspoons active dry yeast (or one 1/4-ounce package) for a .6-ounce package of cake yeast; this will leaven about 4 cups of flour. A 2-ounce package of cake yeast is equivalent to about 6-3/4 teaspoons active dry yeast (or three 1/4-ounce packages); this will leaven about 12 cups of flour.