The Function of Eggs in Cake
This is the fourth in a series of 7 “Cake Batter” classes. This article will explore an important ingredient in cake batter, eggs.
In the 3rd class we looked at one of the cake structure-builders, flour. We learned that low protein, chlorinated cake flour produced a cake with a light and tender texture. Now it’s time to learn about the other structure-builder for cake batter, eggs.
To learn detailed information about the composition and science of eggs as an ingredient, please visit the Baking Ingredients – Eggs page. This class will focus specifically on eggs in pound cake batter.
The Function of Eggs in Cake Batter:
The most important job of eggs in a cake batter is to contribute structure in the form of proteins from both the yolk and the white. The protein coagulates as the cake bakes and, along with the starch from the flour, forms the cake crumb.
So what does all this mean for our pound cake recipe? It means we can alter the cake significantly by manipulating the number of eggs, yolks and whites in the batter.
What Egg yolks do in cake batter
The yolk contributes protein, but also some fat, flavor, and emulsifying lecithin. Because emulsifiers hold water and fat together, adding extra egg yolks to the batter enables the batter to hold extra liquid and, consequently, extra sugar. This helps create a moister and sweeter cake that will still bake up with a good structure rather than falling into a gooey mass.
What Egg whites do in cake batter
When separated from the yolks and whipped to a foam, egg whites can be used to leaven a cake. Whipping egg whites has the same effect as cooking whites- the proteins unfold, reattach and trap water. Since the whipped whites are already partially “cooked” they don’t contribute as strongly to the structure of the cake.
In my testing I found that a cake made with the same proportion of yolks and whites had a softer texture when the whites were whipped and folded into the batter.
How to adjust the proportion of eggs in your cake recipe
- If you find your cake recipe tends to be on the dry side, try swapping out some of the egg whites for extra yolks.
- If you find your cake has a poor structure or is gummy, you can add some extra whites.
- To lighten a cake texture without adding more baking powder separate and whip the whites, then fold them into the batter.
Testing different amounts of eggs in cake batter:
I wanted to see how changing the number of yolks and whites in our pound cake recipe would affect the final product. So I baked six cakes, changing the number of yolks and whites for each test.
I kept the other ingredients (butter, sugar, flour) to 8 oz each. Though I varied the number of yolks and whites, I kept the total weight of eggs for each test at 8 oz.
For the last two tests I separated the eggs, whipped the whites with 2 oz of the sugar, and folded them into the batter before baking.
There is no “right” answer as to which outcome is the best. It’s a matter of taste and what works for your purposes. But knowing how to use eggs to tweak your recipes is a valuable tool for every baker.
You can learn how I used this information to create a great White Cake Recipe from my Vanilla Butter Cake Recipe.
Other cake batter classes:
Next up: Cake Batter Class #5 will explore the function of sugar in a pound cake recipe.
- About Reverse Creaming
- The function of salt and baking powder in cake batter
- The function of flour in cake batter
- The function of fat in cake batter
- The Cake recipe formula
When we’re done experimenting with all the ingredients for this “cake batter” course, we’ll use all we’ve learned to create Pound Cake Perfection.
Thank you for the great information! I have a wonderful recipe for a cake but it uses no eggs. I would like to add one or two eggs for richness and moisture. Would I just sub out some of the liquid ingredients to equal the volume of eggs?
Eggs contain moisture but are also structure builders. It’s hard to say without seeing the entire recipe but you may also need to reduce the flour a bit to balance the recipe. Here’s a post that explains how to balance a cake formula.
Hi Eileen, this is a fantastic series, thank you.
My question comes from trying to modify a classic award-winning recipe that starts with a box cake mix, so that I can make it all from scratch.
It’s the di Saronno Italian Sour Cream Cake. It calls for a butter cake mix-with-pudding in it. Then add two eggs, and two egg yolks. (Plus a few other items.)
My problem came when I tried to start with a scratch yellow butter cake recipe from the Betty Crocker 40th Anniversary cookbook– which called for three eggs– plus the two yolks.
My finished cake came out unevenly textured– dense towards the bottom, more like baked custard.
You’ve taught me that the extra yolks are included to absorb the 3/4 cup extra liquid (Amaretto, yum). So do you think the third egg caused this custard effect? Would I be better trying it with two eggs etc? Or might there also be a problem with all the powders’ proportions? Thank you very much.
Your work should be appreciated first u did a lot of research and gave lot of information
I hope based on your Article I didn’t make a fatal mistake. Recipe called for “3 eggs separated, plus 4 more whites” I misread and only added 1 more white for a total of 4 and I think it should have been seven whites. Cake feels heavy. Am I doomed??
Which recipe you making?
@Eileen Gray, Thanks for replying to my question. Made Martha Stewart’s Zebra Cake. It ended up being very heavy, not a light and airy cake like I wanted, more of a pound cake (3lbs that is-lol). Frosting is delicious however! Fun recipe if you do it right…will try it again with 7 whites.