Cake

Your Egg Yolks Are Smaller Than They Used to Be

July  5, 2016

In baking, egg yolks make a significant contribution to structure, flavor, color, and moisture. Their most important contribution, however, is texture. The natural emulsifying agents contained in egg yolks help suspend ingredients evenly, resulting in a smoother mixture and finer texture.

Many years ago, I started to notice (just by looking) that egg yolks had become smaller in size. Because I weigh my ingredients, I also discovered that when my recipe called for 5 yolks, I now needed to add sometimes as many as 3 extra ones to achieve the correct weight and volume.

But it wasn’t until I taught a class at King Arthur Flour, and complained about the egg yolk situation, that I learned why egg yolks had become smaller for eggs graded the same size (that is, large). One of the students who raised hens said that when the hens are younger, the eggs they lay have a smaller proportion of yolk to white (and a chart in a 1997 research paper from the University of Iowa confirms that younger chickens lay eggs that have 10% less yolk to white). Another factor is that the total number of eggs in a crate is required to add up to 24 ounces/680 grams but each individual egg may vary in size and therefore quantity of yolk.

Photo by Julia Gartland

In recent years, when making génoise, I was disappointed that the texture had become coarser and less velvety than in years past. A génoise is made by beating whole eggs, so it took a while for it to dawn on me that a 4-egg génoise was getting the equivalent of only 3 yolks, which contributed to the textural problem. I now recommend adding an extra egg yolk to compensate for the smaller yolks without throwing off the general balance of the eggs. For a 4- or 5-egg génoise, you’ll likely need to add 1 extra yolk; for a 6- to 8-egg génoise, 2 yolks; and for a 12-egg génoise, you’ll want to add additional 4 yolks.

(The alternative would be to separate the eggs, weigh or measure the yolks and whites, and then recombine them—a process I don’t dare suggest at the risk of being considered excessively over the top!)

In any recipe calling for all yolks or a large number of yolks, my recent books give a range for the number of egg yolks in addition to the weight and volume, based on the assumption that 1 yolk equals 18.6 grams/1 tablespoon plus 1/2 teaspoon/17.2 milliliters.

The discrepancy will make the biggest difference in sponge-type cakes (most, unlike the génoise, call for separating the eggs, making it easy to weigh or measure and compensate for the smaller yolks). Because many sponge cakes depend on eggs alone for leavening (rather than more-controllable chemical leaveners), the exact amount of egg is very important. If one doesn’t weigh or at least measure and, instead, adds whole eggs willy-nilly, the cake will have a disproportionate amount of white, and the cake will balloon out of the pan. For more easy-going cakes, the exact amount of yolk and white is not as critical to the end result.

In my books, I don’t give a range if the recipe calls for only 1 or 2 yolks, but starting with 3 yolks, here is the range (the first number represents how many yolks you’d need with a standard-sized egg yolk; the second number is how many you may need to use to arrive at the correct volume and weight):

  • 3 to 4 yolks
  • 4 to 6 yolks
  • 5 to 8 yolks
  • 6 to 10 yolks
  • 7 to 11 yolks
  • 8 to 12 yolks

Ever had a reliable recipe that suddenly quit on you? Share a baking mystery in the comments below and we'll try to solve it!

8 Comments

Author Comment
Rose L. July 16, 2016
for those of you who are wondering whether or not to remove the chalaza--the white stringy cords attached to the yolk. i once asked James Beard if it was necessary to remove it and he said not necessary but you may want to! when making a custard it gets strained out and when making cakes where the eggs aren't separated i leave it in, but i found that for chiffon cakes, for example, it's best to remove them as they are slower to set than the rest of the egg resulting in tiny pockets of uncooked batter in the baked cake. in scrambled eggs i also find the slightly undercooked chalaza unpleasant. i guess Beard was right--it's up to you!
 
John July 6, 2016
I raise chickens and our yolks are large. I wonder what's up with those eggs from the market ?
 
Eileen S. April 1, 2018
People who raise their own chickens & smaller farmers keep their birds longer so the eggs have a chance to get better proportions. Most of our local producers market eggs from younger birds separately, too.
 
cv July 5, 2016
Funny, I have been adding an additional egg yolk (or two) to my pasta dough in recent years because it didn't feel/look right.<br /><br />Now there's one explanation...
 
MarZig July 5, 2016
I am wondering if this is why Madeline cookies I made didn't turn out. But was is the definitive answer just that we are getting eggs laid by much younger chickens than in the past... And like already asked souls using extra large or jumbo solve the problem
 
Hans C. July 5, 2016
Hm. My wife and I use extra large eggs for just about everything instead of large eggs. I wonder if this has kind of offset the smaller yolks. Baking is chemistry, after all. I often think about whether or not I'm screwing up a recipe by using larger eggs.
 
Author Comment
Rose L. July 10, 2016
We were testing large cakes with whole eggs this weekend and decided to separate the eggs first and see how much yolk was missing. we got jumbo eggs and were deeply disappointed to discover that in order to get 7 yolks we needed to use 9!
 
Marti K. July 5, 2016
I will have to check this out! I have been having trouble with cakes lately, that in the past have been dependable. Interesting.