The Egg Foam Method–That’s a Whole Different Cake

Strawberry "shortcake" made with sponge cake. Lovely!

Li wrote to me the day before yesterday.  He had a question.  Here it is:  “When I first started baking I used recipes from Sweden’s top selling book “Sju sorters kakor” (Seven kinds of cakes/cookies).  The method mostly used starts by whipping sugar and eggs until they turn light and then adding dry ingredients and melted butter. In most American recipes, the creaming method is often used. Have you heard of this Swedish method? Is there a name for it? What do you think of it? I find that the Swedish method in baking muffins makes the muffin tops… not crunchy but more caramelized or something while the creaming method makes them softer.”  Not only is this a great question, but Li also makes some great observations about the differences in the final product depending upon mixing method.

I don’t know this method as the Swedish Method, per se, but I am familiar with this as the “sponge,” “genoise,” or “egg foam method.”  Before I get all ahead of myself, we need to make a distinction between American-style cakes and European-style cakes.  American cakes contain relatively high amounts of fat.  The fat carries flavor, acts as a tenderizer and helps with leavening, specifically in The Creaming Method.  European-style cakes contain relatively little, if any, fat.  This means that European cakes have a more delicate flavor, are drier and also tougher than American-style cakes.

Ew.  That doesn’t sound good at all, does it.  Who wants a dry, tough, tasteless cake?  And how can this be, anyway?!  The Europeans are known for their creative and delectable cakes.  What gives?  Take a dry, tough-ish genoise and soak it with simple syrup flavored with a little liqueur, and you’ve changed the whole ball game.  This dry, kind of tasteless cake soaks up the syrup and, rather than getting mushy like an American-style cake might get when wet, transforms into a lighter-than-air yet moist cake.  Really, really tasty.

Why this big difference in cake styles?  Why would Europeans opt for sturdy, light cakes that need to be soaked with a syrup to be tasty while Americans just load in a bunch of fat?  The primary reason is flour.  I’m not a comparitive botonist (is that even a real job?) so I don’t know all of the reasons why, but the deal is that the wheat flours used in Europe have a much lower protein content than American wheat flours.  Knowing this fact helps to clarify things a little.

Remember, flour and eggs play together on Team Structure.  Fat and sugar are on Team Tender.  If European flour is low in protein content (gluten), it stands to reason that the eggs will have to step up their game and play a more front-and-center role in giving the cake structure.  Since American flours are higher in protein, more gluten can develop.  So why not just dump some syrup on it?  If you activate too much gluten when making an American-style cake with American flour, your cake will be chewy.  Syrup can add moisture to a dry cake, but it can’t hide chewy.

Here’s how the whole Egg-Foam Method works.

• Whisk dry ingredients together thoroughly.
• Whip eggs/yolks/whites (depending on your recipe) with sugar until very light in color, tripled in volume and creamy.  You’ll know it’s ready when a bit of egg mixture dropped back into the bowl sits on top of the rest for at least 10 seconds before sinking back in.  The egg mixture will be very light and poufy.  Some recipes will call for whipped yolks and whites.  In this case, whip the yolks first, as the emulsifiers in the yolk will allow this mixture to stand for a few minutes without deflating.  If you beat the whites first, you’ll end up with a watery mess.  I’m telling you.
• Pour egg mixture into a large bowl.
• Sift dry ingredients over the egg mixture and gently but thoroughly fold together
• Fold in melted butter at the end (if your recipe calls for it).

After baking, egg-foam cakes are generally completely cooled in the pan upside down (so they don’t collapse before the proteins in the eggs and flour set up).

You want a recipe?  Okay:

Basic Lemon Sponge Cake

• 6 eggs, separated
• heavy pinch of salt
• 6.5 oz. sugar
• 1 TBSP fresh lemon juice
• zest from one lemon
• 4.5 oz. all purpose flour

Whip the yolks and salt until slightly thickened and lighter in color.  Gradually add halfof the sugar, then the zest and juice.  Continue whipping until the yolks are very light and billowy.

Pour the egg mixture into a large bowl.  In another large clean bowl with a clean whisk, whip the whites until they are foamy.  Gradually add the rest of the sugar and whip to medium-soft peaks.  If you whip your whites to stiff peaks they will be too hard to fold into the yolks, so settle down–you want the peaks to slump over quite a bit when you raise the whisk out of the whites.

Dump the whites on top of the yolks.  Sift the flour over the top.  Don’t dump in the flour, or you’ll break a lot of your bubbles and have a flat, dumb cake.  Gently but thoroughly, fold the three components together.  Bake in a parchment-lined ungreased pan at 325 degrees, F, until the top springs back when you press on the center.

This lemon sponge would be lovely as a base for strawberry shortcake.  Slice it in half, horizontally, and fill with beautiful macerated berries.  The cake will soak up the juices, and you will be very happy.  You could also just soak it with a simple syrup made from 1 1/2 parts sugar to 1 part water.  Bring to a boil, then cool.  Add a splash of vanilla, lemon extract, Grand Marnier–whatever sounds good.

Thanks, Li, for the question.  I hope I’ve been able to clarify the difference between this method and the creaming method.  Oh!  I almost forgot.  Li mentions the textural difference between final products when using the different methods.  In recipes that call for a lot of whipped eggs, you are apt to get a thin layer of “crunchy” on the outside of your baked goods.  Sometimes this layer isn’t even attached to the rest of the cake–think about brownies.  They do this sometimes.  This thin, crunchy layer is actually a coating of baked meringue.  Since this layer can be kind of waterproof, it’s best to slice off the very outside crust from a genoise or sponge cake before you soak it with syrup.

OK, I think I’m done now.  Enjoy your sponge cakes, people!