Why Cakes Rise

• Although there are hundreds of different cakes, most fall into two broad categories. Some get much of their rise and texture from creaming sugar together with butter or other fats. This creates millions of tiny air pockets, which trap gases from the baking soda or baking powder and make the cake rise. For most other cakes, the rise comes from egg whites finely whipped to a foam. These expand when the cake is baked, then set as the eggs cook in the oven's heat. Some sponge-type cakes, and almost all creaming-type cakes, use baking soda or baking powder to make the cake lighter and fluffier.

Creaming-Method Cakes

• The difference between hand mixing and machine mixing often shows itself in cakes that use the creaming method. Generally speaking, the longer the butter and sugar are creamed together the lighter and fluffier they'll become. That in turn means a lighter and fluffier cake, thanks to the added air. Mechanical mixers do this faster and more efficiently than a baker with a wooden spoon, so hand-mixed cakes can be somewhat denser than cakes mixed mechanically. However, a patient baker with a strong wrist can achieve results that are every bit as good.

Foam-Method Cakes

• Cakes raised by whipped egg whites can also be denser when made by hand, if the baker isn't patient enough to achieve a fine, long-lasting foam. Most recipes call for the cake's egg whites to be whipped to stiff peaks. That means if you lift the whisk from the bowl, the foamed whites will hold their shape and form a sharp, clean line where the wires passed through the foam. This takes just moments in a mixer, but can require several minutes of effort when done by hand.

Doing It by Hand

• In both cases, cakes benefit from having this preliminary mixing process done mechanically. Still, hand mixing can often give a better result. With creaming-type cakes, once the liquids and dry ingredients are combined the cake should be mixed minimally. Too much mixing can toughen the cake by creating strong gluten strands in the batter, giving the finished cake large holes and tunnels through the chewy crumb. Foam-type cakes must be mixed gently to avoid breaking their delicate bubbles, a task for which mechanical mixers are ill-suited. Even when a mixer is used in the early stages of the recipe, finishing the batter by hand can give a better final result.