Adding Yeast to Crêpe Batter

A crêpe is the French equivalent to the American pancake and differs only in that American pancakes are usually leavened with baking powder and the batter is made thicker. Baking powder contains sodium bicarbonate (baking soda) and tartaric acid or some other source of acidity. When the mixture is moistened, the baking soda reacts with the acid and forms carbon dioxide, which becomes trapped in the gluten structures of the flour and causes the batter to rise. Blini, pancakes originally made with a mixture of buckwheat and regular flour, are instead leavened with beaten egg whites and yeast. Yeast ferments sugars and starch contained in the flour and, like baking powder, produces carbon dioxide, which causes the batter to rise. When you add yeast to a thick crêpe batter and let the mixture rise for a couple of hours in a warm place or overnight in the refrigerator, you can ladle the batter onto a hot buttered griddle or nonstick pan and make yeast-leavened pancakes, which are very similar to blini. You can bake yeast-leavened crêpe batter in a savarin mold (a ring mold) and you’ll end up with a kind of cake, called a savarin, suitable for dipping in syrup flavored with rum or other liquor. If you fold yellow raisins into the batter and bake it in individual dariole molds, you’ll get babas. Dip the babas in a rum syrup, and you’ll have babas au rhum.