Why Adding Hard-Boiled Eggs to Shortbread Makes the Best Cookies Ever

If you've ever made cookies, you know that there's science involved. The eggs need to be the correct size, the flour should be weighed, the oven should be at precisely the right temperature, the list goes on. It's no wonder then, that we're always looking for hacks or ways to create the perfect cookie—especially ways that aren't complicated. Turns out there is one and it involves hard-boiled egg yolks.

You read that right, hard-boiled egg yolks are what your shortbread cookies are missing. Adding 1 or 2 hard-boiled egg yolks to your recipe is the secret that will make your shortbread turn out perfect every single time.

Why Should You Add Hard-Boiled Egg Yolks To Shortbread?

Let's start with a bit of food science. Flour contains two proteins, gliadin and glutenin. The action of kneading the flour with a liquid brings those two proteins together, creating gluten. It's that magical marriage of proteins that gives dough it's stretchy structure, ensuring your bread and pizza doughs hold their shape. It also gives those foods that drool-worthy chewy texture. Creating that tight bond is great for bread and pizza, but NOT so good for your cookies. A hard, overly chewy shortbread cookie isn't high on the list of favorite foods.

Enter hard-boiled egg yolks. Once passed through a fine sieve, they can be mixed right into the flour. These fat-filled pieces intersperse with the particles of flour, acting as a barrier between them. This prevents too much gluten development resulting in crumbly, soft and luxurious cookies.

Does Adding Hard-Boiled Eg Yolks To Shortbread Work?

It almost seemed too good to be true to us as well, that's why we gave it a try. We used a basic shortbread cookie recipe and made two versions. One batch was made as written, the other with the addition of two hard-boiled egg yolks. The results were consistent with the science. The cookies made with the egg yolks were more tender, lighter and melted in your mouth versus those without. That being said, the addition only marginally impressed (my two) taste-testers, who claimed they loved both versions.

How To Add Hard-Boiled Egg Yolks To Shortbread

• Use one or two hard-boiled egg yolks per batch (1 to 2 dozen) of cookie.
• Let the egg yolks cool completely before adding them to your dough.
• Use a fine-mesh sieve or very fine cheese grater to crumble the egg yolks.
• Add the egg yolks directly to the flour mixture and use a fork to combine.

The Bottom Line

Adding hard-boiled egg yolks to a basic shortbread recipe makes cookies more tender with the perfect buttery-soft texture. The addition is a sure-fire way to improve the texture of your cookies, but perhaps not always worth the extra time and effort. We'll leave it up to you!