Formula Balance in Sponge Cakes

An extremely heavy or rich sponge contains equal parts eggs, sugar, and flour. In other words, for every 8 ounces (225 g) eggs (approximately 4), such a sponge cake contains 8 ounces (225 g) sugar and 8 ounces (225 g) flour. This ratio is the formula for a standard pound cake. A medium-bodied mixture contains 5 ounces (140 g) each flour and sugar for the same 8 ounces (225 g) eggs. In the lightest and most common type of sponge cake, the sugar and flour weights are 4 ounces (115 g) each per 8 ounces (225 g) eggs. The sugar and flour ratio can be altered slightly in individual formulas, such as 3 ounces (85 g) sugar and 4 ounces (115 g) flour, or vice versa. If butter is used, the amount is generally about one-fourth the weight of the sugar or flour, and it is added at the end.