Baking Cakes

Cake baking can be divided into three stages: expansion, setting, and browning. During the first stage, the batter expands to its full volume. As the batter temperature rises, the gases in the air cells expand, chemical leavening releases carbon dioxide, and beginning around 140°F/60°C, water vapor begins to form and expand the air cells even further. During the second stage of cake baking, the risen batter is set into its permanent shape by the oven heat. Beginning around 180°F/80°C, the egg proteins coagulate, and starch granules absorb water, swell, and gelate. The actual setting temperature depends strongly on the proportion of sugar, which delays both protein coagulation and starch swelling; in a high-ratio cake, the starch may not gelate until close to 212°F/100°C. In the last stage, batter solidification is completed, flavor-enhancing browning reactions take place in the now-dried surface, and the cake often shrinks slightly, an indication that it should be taken out of the oven. Another test of doneness is to probe the center with a toothpick or wire cake tester, which should come out clean of any batter or crumb particles.