Adding eggs one at a time
After creaming together butter and sugar, the next ingredient in many cookie recipes is eggs.
Did you ever wonder why? I mean, it doesn’t matter right? If you add them to those ingredients all at once for convenience then no problem.
Mother Knows Best
All of those extra little tips my mother stressed I follow, like creaming butter and sugar completely and allowing eggs to come to room temperature before adding them slowly really did have a purpose.
Even mixing vigorously between each addition while continuously scraping the sides and bottom of the bowl were impressed upon me as I learned from my mother I didn’t dare ask why.
Who decided that anyway? Your mother? Your Grandmother? These are modern times. We don’t mix by hand anymore.
Little did I know I was actually creating a stable emulsion of liquid and fat in the batter.
When this is done correctly, the cake will have a springy and light texture.
If the batter is not properly emulsified, the resulting cake can be uneven and flat, flavorless, and have a heavy texture. Your cookies can spread and become flat.
It’s even possible for the cake to sink into itself when baking.
The End Results
The sugar goes into the bowl first. Then the eggs should be added one at a time, each one thoroughly beaten in before the next is added.
And they should be at room temperature for the best results.
The reason is to the mixture must allow the creamed butter and sugar mixture to most effectively retain its trapped air.
In a recipe when two eggs are added one at a time, it takes about 30 seconds to incorporate the air into the creamed butter and sugar.
When both eggs are added at once, the time to incorporate into the butter and sugar was slightly over two minutes.
While the difference in time might not seem significant, the difference in the finished cookies was.
Eggs added one at a time lead to cookies that are thick and chewy.
Eggs added all at once produce cookies that spread, become unevenly shaped, and are not as chewy.
Eggs should be also added one at a time to cookie dough, bread dough, and layer cake batter.
When the eggs were added together for those baked goods it took longer to incorporate them and the cakes turned out denser and slightly rubbery.
The fact is, like oil and vinegar, eggs and butter don’t mix naturally.
It’s a matter of chemistry.
Butter is at least 80 percent fat, while eggs contain large amounts of water.
So any time you add more than a single egg to creamed butter, it’s best to do it slowly to give the mixture time to thicken and emulsify.
Who knew?? Did you?
So what is emulsion anyway? This is the geeky part. Feel free to skip down to The Bottom Line.
An emulsion is the suspension of small globules of one liquid in a second liquid with which the first will not mix. Just like oil and vinegar.
To create an emulsion you must slowly add eggs to the butter mixture, one at a time.
Beating rapidly to suspend the water from the butter and egg whites in the fats from the butter and egg yolks is what causes this to happen.
Lecithin, an emulsifier found in eggs, helps to stabilize the emulsion, as does aeration from steady, rapid beating.
Adding the eggs slowly makes it easier disperse the liquid and promote even suspension of liquid in fat.
This ensures that all of the ingredients are around 70 degrees Fahrenheit, or room temperature. And will also help them combine more easily and smoothly.
This action promotes aeration in the egg whites and prevents curdling. If your emulsion breaks and looks separated do not worry. There are easy ways to fix it and move on.
But that is a whole new Tip Friday.
The Bottom Line
If your family is like mine those cookies won’t last long.
So there are two things to worry about.
That the cookies are warm.
And the milk is cold.
Now that you know to Add Eggs One at a Time, check out my tip on Separating Eggs.