Active dry yeast, used to leaven dough, is sold in packages containing 2 1/2 teaspoons (1/4 ounces/7 grams) and also in bulk in some food stores. Quick-rising yeast raises dough in about a third or half the time required for regular yeast. Yeast is also available in fresh cakes; substitute 2 ounces (60 g) cake, or compressed, yeast for 1 tablespoon active dry yeast. Store dry yeast in a cool, dry place; refrigerate cake yeast.