Every Part Of That Cake Has Function

Each ingredient in a cake recipe has a particular function, Susan G. Purdy explains in “Let Them Eat Cake: 140 Sinfully Rich DessertsWith a Fraction of the Fat” (William Morrow).

In the professional baking guide “Practical Baking,” she says, author William J. Sultan devised a convenient system for characterizing baking ingredients.

Purdy modified it slightly and finds it a useful guide, particularly when working to remove fat from baked products. Even without that goal, though, it’s fascinating to understand, perhaps for the first time, exactly what each egg yolk and speck of flour is doing in that bowl.

Here’s Purdy’s modified list:

Binders and tougheners (provide structure and bind ingredients): flour, milk solids, egg whites.

Tenderizers (soften the crumb by cutting the development of gluten in wheat flour): sugar; fat; egg yolks; chocolate; acidic foods such as yogurt, sour cream, buttermilk and vinegar; honey; molasses.

Moisteners (moisten the crumb, lengthen storage time): milk, water and some other liquids, such as eggs; sugar syrups; honey; brown sugar.

Dryers (absorb and retain moisture, provide body): flour, milk solids, starches, egg whites.

Flavorers (enhance or provide flavor): chocolate/cocoa; butter; eggs; fats; specific flavoring agents, including extracts, citrus zests, coffee and nuts.