Yolks Hard & Soft

Reader Daniel asks:

I was wondering if you might have an insight into a question I have been trying to answer for quite some time. In some traditional cake recipes from central Europe (usually cakes that involve ground nuts as well, like a Linzer), the dough calls for the addition of hard-boild egg yolks, passed through a sieve. I always wondered what this is supposed to do to the consistency of the cake vs. using raw yolk, and what may have prompted the bakers to use yolks in such an unusual way. Do you happen to know anything about that?

Great question, Daniel! The answer is that hard boiled egg yolks are a tenderizer. Consider that for the most part wheat flour is the “bulk” — the building material — of a cake. There’s just one complicating factor: it contains gluten. That gluten is important to some degree. The network of intertwined molecules helps trap the gas and steam that allows the cake to rise.

Too much, however, and the cake gets tough. This is where the hard boiled egg yolk comes in. Think of it as “bulk” that comes with no other attachments. Literally. Added to a batter or dough the cooked bits (which are actually huge in the context of a cake structure) interrupt the gluten network. Not so much that it doesn’t function, but enough that it’s more tender than it would otherwise be (ground nuts do the same job, but if you want a lighter, fluffier texture, cooked yolk is a better solution).

An uncooked yolks added to the batter wouldn’t work as well. The liquid water and fats would just disperse into the mixture. Yes they’d add moisture and a little tenderness, but not nearly as much as the cooked yolk. Also the cooked yolk adds a pleasing yellow hue. I like to add it to biscuits and pastry crusts as well. Hope this helps!

20 thoughts on “Yolks Hard & Soft”

  1. Yuck!! If there is anything that turns my stomach, it’s hard boiled eggs (actually eggs period). I’m not sure how I came by my loathing, but I can’t stand them.

    1. You can’t taste it in the finished product, Ellen. Does that help? 😉

      – Joe

      1. Probably not. The very sight of hardboiled eggs makes me sick. Rose Levy Berebaum’s recipe for angel biscuits calls for HB egg yolks and I knew that would be one recipe I’d never try.

        1. Ah well. No worries, Ellen. There’s a wide world of non-hardboiled-egg-containing foods out there for you to turn to — like Pop Tarts!

          Unless you’re filling them with egg salad. Hmm….

  2. Great question! I have wondered that myself. I have seen it many times in my moms old Danish baking recipes. Is this technique something unique to Northern European baking or is it an all over the world type of thing?


    1. Hi Eva!

      I’ve only seen it in European baking, usually of the northern stripe, i.e. Scandinavian and German/Polish baking. It might have been employed elsewhere, but my guess it that it originated with the cake bakers in those ares.

      – Joe

  3. Hi Joe,
    First off, I really live the scientific approach you take on your blog. It’s really great knowing the reasoning behind something instead of just blindly following a recipe.
    Secondly, do you think this technique would work in a recipe using yeast, such as a raised doughnut for example. I’ve tried many recipes ( not yours yet though) and I just don’t get the same extra fluffy/ tender doughnut shop results.
    Thanks for your time, look forward to seeing what you’ll be coming up with next.

    1. Hi Jacqui!

      That’s an interesting idea. I never thought about it, actually. I’m not sure it would work as well in a yeast application. I prefer to add liquid yolk in that case, to crank up the liquid fat and lower the water content (which can toughen a yeast doughnut). I did just that recently when I revamped my yeast doughnut recipe. They’re even more tender now…try them! Right from the fryer they’ve got a little crunch to them, but after a short sit they get very tender. Not quite as tender as Krispy Kreme, but pretty darn close if I do say so myself. Let me know what you think!

      – Joe

  4. Just to add to the list: the Cooks’ Illustrated recipe for French sable cookies (incl. checkerboard cookies) also calls for the inclusion of a hard-boiled egg.

    (from their website [subscription required]): “These recipes claimed that the hard-cooked yolk would deliver a sandy cookie. Skeptical, but intrigued, we cooked and cooled an egg and added the mashed yolk to the butter and sugar during creaming. Voilà! This unusual step eliminated moisture and perfected the texture of the cookies.”

    I’ve made this recipe and it does exactly that!

    Those Europeans sure are a smart bunch 🙂


    1. Ah yes! A very nice way to cut the butter content by a bit and undermine the gluten even further. A very versatile technique indeed!

      Thanks Pete!

    2. But also, let’s not jump to conclusions about the Europeans here, Pete. Don’t forget that many of them wear socks with sandals, eat even finger foods with knives and forks, and put two toilets in the same room. Nope, I’d say the jury is still out on those people.

      – J

  5. Well, thank you for this light bulb moment!

    I once read the recipe for James Beard’s shortcakes (as in strawberry adorned shortcakes) that he never published. It had these sieved egg yolks in it and that was enough to convince me that it wasn’t something I meant to try no matter what the recommendation that came with it.

    Maybe now I’ll give it a try next year when strawberry season rolls around again.

    1. Indeed Rainey, hard cooked egg yolks can be very useful in short cakes (cookies, biscuits) of many kinds. Give’em a try…you’ll be glad you did!

      – Joe

  6. Okay. You got me started looking for recipes that use a sieved hard boiled egg yolk. I’ve found a few but I’m curious if you could add 1 or 2 to any cake recipe or bar recipe and get good results or if you take a recipe out of balance by adding boiled egg yolk to it. I decided to ask the guy who started me down this path. At the moment I’m only eating the egg white part and am accumulating yolks…though I did read they freeze well unlike raw egg yolks which I have been told will get chewy if frozen unless you cover them in water. I have avoided this problem in the past by using the raw egg yolks in a curd and freezing the curd.

    1. Hehe….hey Linda!

      Interesting quest you’re on. First thing is yes, you certainly can freeze cooked egg yolk, then mete it out however you will for various applications. And as far as those applications go, the sky is the limit. Cooked egg yolk works as a tenderizer in all sorts of things, but especially quick breads and short bread-type cookies and bars. I think it’s little used because many recipe writers consider it a bit of a pain in the neck as an ingredient. However if you have it around, use it! I’d view any recipe that calls for a chemical leavener as a potential opportunity. Go nuts and get back to me with your results! 😉

      – Joe

  7. Thanks, Joe! I’ll keep you informed! The amount I’m collecting will give me plenty to work with.

  8. Update: so far I have used two boiled egg yolks in a cinnamon coffeecake and just added two to a spice Bundt cake with a brown butter vanilla bean glaze. I did see the coffeecake cut and the crumb was beautiful. I was told it was really good taste wise. The spice cake is being shipped to a friend and I won’t see it cut but the cake externally looks gorgeous and it feels soft to the touch when moving it to glaze. It already had quite a few eggs…but I thought what the heck…no such thing as too many eggs as long as two of them are yolks only and hard.boiled, right?? I should hear about it so I will inevitably know but that’s my experimentation so far!! Since I’m collecting 14 boiled egg yolks a week for another week or so…I have more to play with!!

    1. Keep updating me on your experiments, Linda! You’re doing great work!


      – Joe

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