Bakeshop Skills Class: Cake Basics, Sponge Types, Mixing Methods and Baking Tips

Cakes developed from early sweetened breads and eventually became a distinct category of baking. Modern cake flour is milled from soft wheat and has a lower protein content than bread flour or all-purpose flour, helping produce a finer and more tender crumb.

What Is a Cake Sponge?

The foundation of many cakes is a sponge made primarily from eggs, sugar and flour. The balance of these ingredients affects the cake’s weight, texture, crumb and moisture.

For class purposes, the sponges were divided into three general categories:

• Heavy cakes: These use relatively equal proportions of major ingredients. Pound cake is a common example.
• Medium cakes: These contain less flour and sugar in relation to the eggs and generally have a lighter texture than pound cake.
• Light cakes: These use relatively little flour and often rely heavily on whipped egg whites. Angel food cake is a common example.

How Eggs Affect Cake Texture

Egg whites provide structure and can hold air when whipped. A greater proportion of egg whites generally produces a lighter cake with a more open crumb.

Egg yolks add fat, flavor, color and richness. A greater proportion of yolks usually creates a denser, more tender cake with a finer crumb.

The way the eggs are mixed is just as important as the quantity. Properly whipped eggs provide much of the leavening in traditional sponge cakes.

The Role of Sugar

Sugar does more than sweeten a cake. It also contributes to browning, tenderness, moisture retention and aeration.

Using too little sugar can make a sponge dry, firm and less tender. It can also reduce browning and interfere with the stability of whipped eggs.

Too much sugar can weaken the cake’s structure and delay setting during baking. Successful cake formulas depend on maintaining the correct balance among sugar, flour, eggs, fat and liquid.

How to Fold Flour into Cake Batter

Flour should usually be folded into an aerated egg mixture only until no dry streaks remain. Excessive mixing can deflate the batter and develop too much gluten, producing a dense or rubbery cake.

Use a large flexible spatula and cut down through the center of the mixture. Sweep along the bottom of the bowl, lift the batter over itself and rotate the bowl before repeating.

Vanilla and other liquid flavorings are generally added to the wet ingredients before the flour is folded in.

Adding Butter, Fruit and Nuts

Melted butter or oil may be added to improve flavor, tenderness and moisture retention. Melted butter should be warm and fluid but not hot.

Because fat can deflate an aerated batter, it is generally folded in after the flour. Mixing a small amount of batter into the melted butter first can make it easier to incorporate evenly.

Fruit, nuts and other additions are usually folded in near the end of mixing. Heavy additions should be distributed evenly without overworking the batter.

Using Nut Flour in Cakes

Nut flour adds flavor, fat and tenderness, but it does not provide the same structure as wheat flour.

In the formula discussed during class, one ounce of wheat flour was removed for every three ounces of nut flour added. The total weight of the nut flour was not intended to exceed the weight of the sugar in the recipe.

These proportions are formula-specific rather than universal. Nut flour substitutions should be tested carefully because different nuts contain different amounts of fat and moisture.

Adding Cocoa or Chocolate

Sifted cocoa powder can be combined with the dry ingredients. Because cocoa absorbs moisture and affects structure, it should not simply be added to a formula without considering the flour and liquid.

The class guideline was to use no more than approximately three ounces of cocoa powder per pound of flour and not to exceed the total weight of the flour.

Unsweetened melted chocolate may also be folded into the batter. The class guideline was no more than approximately five ounces of unsweetened chocolate per pound of flour.

When using sweetened chocolate, the sugar in the recipe should be reduced to compensate. Melted chocolate is best folded in gradually after the flour has been incorporated.

The Warm Method

The warm method begins by heating whole eggs and sugar together over a water bath. The mixture is whisked until the sugar dissolves and the eggs become warm.

The warmed egg mixture is then whipped at high speed until it becomes pale, thick and reaches the ribbon stage. At ribbon stage, batter falling from the whisk briefly holds its shape on the surface before disappearing.

The dry ingredients are folded into the whipped eggs. Melted butter or oil may then be added for additional moisture, flavor and tenderness.

Génoise is a common example of a sponge made with the warm method. Because many génoise formulas contain little fat, the finished layers are often brushed with flavored syrup before assembly.

The Cold Method

The cold method separates the eggs. The yolks are whipped with part of the sugar, while the egg whites are whipped separately with the remaining sugar to the required peak.

The whipped whites are folded into the yolk mixture, followed by the dry ingredients. This method can produce a light sponge with an open texture.

Chiffon cake uses separated eggs and whipped whites, although it also contains oil and chemical leavening. Angel food cake relies almost entirely on whipped egg whites and does not contain egg yolks.

How to Tell When a Sponge Cake Is Done

A sponge cake is generally finished when the center springs back after being pressed lightly and a toothpick inserted near the center comes out clean or with a few dry crumbs.

The edges may also begin pulling slightly away from the pan. Avoid opening the oven too early because a fragile sponge can collapse before its structure has set.

Preparing Cake Pans

Pan preparation depends on the type of cake. Foam cakes such as angel food cake often need to cling to an ungreased pan as they rise.

Other sponge and butter cakes may require parchment, grease or both. Follow the preparation instructions for the specific formula rather than applying one method to every cake.

When parchment is used on the bottom, a small knife or thin spatula can be run carefully around the edge after cooling to release the cake.

Cooling Sponge Cakes

Cooling is part of the baking process. A cake that is handled, filled or frosted while warm may compress, tear or release excess steam into the filling.

Some delicate foam cakes are cooled upside down so gravity does not compress their structure. Other cakes should cool briefly in the pan before being transferred to a rack.

Always use the cooling method recommended for the particular type of cake.

Baking Temperatures and Pan Sizes

Many cakes are baked between 350°F and 400°F, although the correct temperature depends on the formula, pan material, batter depth and desired texture.

When converting a layer cake recipe to cupcakes, the smaller portions generally bake more quickly. When converting cupcakes into a larger cake, the deeper batter usually requires a longer baking time.

Temperature changes are not automatic. Begin with the original recipe temperature unless the formula or pan size provides a reason to adjust it.

Using Chemical Leavening

Traditional sponge cakes rely heavily on air incorporated into eggs, but baking powder may be used in some formulas to provide additional lift.

Baking soda requires an acidic ingredient to react properly. It should not be substituted directly for baking powder unless the formula contains enough acid and the quantities are recalculated.

Essential Cake Tools

• Offset spatula: Useful for spreading batter, fillings and frosting.
• Straight icing spatula: Useful for smoothing cake tops and sides.
• Pastry cutter or wheel: Useful for trimming pastry, sponge and decorative components.
• Rotating cake stand: Helps with filling, frosting, smoothing and piping.
• Digital scale: Provides more accurate and consistent measurements than volume cups.
• Pastry bags, couplers and tips: Used for piping borders, lettering and decorations.
• Cake boards: Provide a stable base for assembling, moving and presenting cakes.

What We Made

Only the lemon pound cake was completed during the first week. The remaining cakes and sponge components were prepared for use in later classes.