The mixing method used is the foam mixing method.
This mixing method is used primarily for foam cakes because of the important egg preparation involved and used. The method consists of the dry ingredients being sifted together. Sifting occurs three times in this method. The first time the flour and other ingredients are sifted separated and not measured. The last two times the dry ingredients should be measured then sifted together. When you start beating the egg whites, beat to the first stage, foamy. Add the cream of tartar and salt which will help stabilize the egg whites. Once the egg whites get to the second stage, soft peaks, start gradually adding the sugar to form stiff peaks, the third stage. The last step in this method is to fold in the dry ingredients to the egg whites.
Sifting the dry ingredients is very important in the texture of the cake.
The first stage in making the meringue is whipping the egg whites to a foamy mixture.
The second stage is soft peaks where the egg whites are now a white fluffy mixture. To test for soft peaks, is when you pull the whisk up it should create a mountain with a slight bend.
The final stage is stiff peaks where the egg whites are bright white and glossy. To test the stiff peaks, is by using your whisk to pull it up and the egg whites should stand straight up.
The final step in the mixing method is to fold in the dry ingredients with the egg whites.
Chocolate Angel Food Cake:
1 1/2 cups (360 ml) egg whites (you will need about 12 large egg whites)
1 1/2 cups (300 grams) granulated white sugar, divided
1 cup (100 grams) sifted cake flour
1/4 cup (25 grams) unsweetened cocoa powder (regular or Dutch-processed), sifted
1/4 teaspoon salt
1 teaspoon cream of tartar
2 teaspoons pure vanilla extract
1. Preheat oven to 350 degrees F (180 degrees C) and place rack in center of oven. Have ready an ungreased 10 inch (25 cm) two piece tube pan.
2. Separate the eggs, whites in one bowl and yolks in another. Cover whites (you need 1 1/2 cups (360 ml)) with plastic wrap and bring to room temperature (about 30 minutes). Cover yolks and store in refrigerator or freezer for another use.
3. In another bowl, whisk or sift together 3/4 cup (150 grams) granulated white sugar, the sifted cake flour, sifted cocoa powder, and the salt.
4. In your electric mixer, with the whisk attachment, (or with a hand mixer) beat the egg whites until foamy. Add the cream of tartar and continue to beat until soft peaks form. Gradually beat in the remaining 3/4 cup (150 grams) granulated white sugar, a tablespoon at a time, until stiff and glossy peaks form. Beat in the vanilla extract.
5. Sift the flour mixture (about one quarter of the flour mixture at a time) over the egg whites, and gently fold the flour into the egg whites using a rubber spatula or wire whisk. (It is important not to over fold the batter or it will deflate.)
6. Pour the batter into the pan and run a metal spatula or knife through the batter to get rid of any air pockets. Smooth the top and bake in the oven for about 35 - 45 minutes or until a wooden skewer inserted in the center of the cake comes out clean and the cake springs back when gently pressed. Do not over bake. (The top of the cake will have cracks.)
7. Immediately upon removing from the oven invert (turn upside down) the pan. Suspend the pan by placing the inner tube on the top of a wine bottle or flat topped glass. Allow the cake to cool compleely (about 1 1/2 hours). Then run a metal spatula or knife around the sides and center core of the pan to loosen the cake and then remove the cake from the pan. Next, run a metal spatula or knife along the bottom of the pan and remove. Place onto a serving plate. The cake will keep covered for a few days at room temperature or for about a week in the refrigerator.
8. This cake can be eaten alone with just a dusting of cocoa powder or confectioners' sugar. Can be served with fresh berries and softly whipped cream.
Recipe from the Joy of Baking http://www.joyofbaking.com/ChocolateAngelFoodCake.html
This recipe is a perfect example of a foam cake because there is no fat in the recipe. The recipe uses about 12 eggs but only the egg whites are used. Another way that shows this is a foam cake is the leavening agent is a mechanical method, the egg whites are beaten to stiff peaks.
In this video, the recipe being represented is shown above. The lady in the video separates all the egg whites from the yolks. Another similarity is she sifts the dry ingredients together which is a key feature in the mixing method of foam cakes. Another important feature done in the video is she creates a meringue with the egg whites. The meringue makes the cake have a light, airy texture which is the definition of a foam cake.