This post will teach you how eggs function in baking, or put another way, it will hopefully help answer the question about what eggs do in baking. You may also enjoy my post about how to temper eggs.
Eggs are really versatile, and because they have 2 parts that behave differently, we’ll look at how egg yolks work, what egg whites do, and how whole eggs act in baking.
This post will focus mainly on cakes with some information at the end about custards.

Part of a series called Ingredient Function,

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What Eggs Do In Baking

The egg is quite possibly the most versatile basic baking ingredient on the planet. I think it has to do with its having two parts: a fatty yolk and a proteiny, watery white.

You can also use:

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  • just yolks
  • just whites
  • a combination of the two.

Where to begin? Like Maria, I say let’s start at the very beginning…

An overhead shot of a dozen different colored eggs in a carton on a distressed background.
Eggs come in all shapes and sizes, but they all function the same ways in cake batters.

Photo by Kelly Neil on Unsplash

Egg Basics

An egg is “the hard-shelled reproductive body produced by a bird and especially by the common domestic chicken; also :  its contents used as food.” So sayeth Mirriam-Webster online.

Thanks, Mirriam Webster for not bothering to discuss the contents of an egg, because for most of us interested in baking with eggs, we are only interested in what is inside the shell.

Parts of the Egg

Eggs contain several structures including membranes and air pockets and such, but the main parts of the egg we are concerned with as bakers and cooks are:

  • the yolk
  • the albumin or white
  • the whole egg, or the yolk and white together

A Note on Egg Whites

I will say here that the albumin can be further divided into thick albumin and thin albumin.

I’m sure you’ve all seen this: there’s a thicker, almost jelly-like white around the yolk and a thinner, more watery substance that runs out into your pan or bowl.

The fresher the egg–the more recently laid–the more of the thicker part there is and the less of the thinner.

That’s why older whites are preferable to younger whites for whipping. It’s much easier to whip air into a thinner mixture than it is with a thicker one.

What Do Eggs Do In Baking?

To really understand all the myriad ways eggs function in baking, we have to look at the ways eggs are called for: whole eggs, just yolks or just whites. Because nothing is ever easy. Still, this will be Fun and Educational!

Whole Eggs

3 brown eggs on a wooden surface next to a white bowl containing a whole cracked egg.
Whole eggs perform a ton of functions in both baking and cooking.
 Photo by Gaelle Marcel on Unsplash

The fat/protein/water content of whole eggs is:

  • 12% fat
  • 13% protein
  • 73% water
  • 2% minerals and such.

A whole large egg has about 80 calories.

  • They add structure in the form of protein. As eggs bake in a cake, the proteins denature and coagulate which, along with the starches in flour help form the overall structure of your baked goods. Too much egg not balanced with sugar and fat (which both tenderize) and yield tough, dry or chewy results.
  • Yolks contain emulsifiers that help to form a thick, luscious batter that doesn’t separate. An emulsifier helps two items who don’t normally get along (fat and water in this case) get along. That’s why adding just a bit of egg yolk to a salad dressing helps to keep the oil and vinegar in solution. In this case, eggs add volume to batter and an even texture to the final product.
  • They contribute to browning because of Maillard reactions. Maillard reactions are the set of browning reactions that occur when proteins are heated. As well, they lend a yellowish cast to batters and dough.
  • The yolks add some trace minerals and up the nutritional value while whites up the protein content.
  • They contribute to the overall flavor of whatever you’re making, partly because the fat in the yolks helps to carry other flavors.
  • Since eggs are mostly water, they contribute to the overall moisture content of whatever you’re making. If you are making an enriched bread for example and you decide you want to only use yolks rather than whole eggs, you will have to increase the amount of water or other water-type liquid in the formula so that the bread won’t be too dry. So yes, I realize that I have said eggs both dry and contribute moisture. Both are true. There are many sides to eggs.
  • The fat in yolks helps to shorten gluten and tenderize the final product.

Recipes Containing Whole Eggs

Egg Yolks

Although the yolk makes up roughly 1/3 of the volume of a whole egg, it contains half the protein, all of the fat and almost all the vitamins and minerals. It also contains three times as many of the calories as the white (60 as opposed to 20). Yolks are made up of 49% water, 17% protein and 32% fat along with 2% minerals and such.

  • While yolks are made up of roughly half water, the actual amount is about 8 grams, or 1 1/2 teaspoons. This is a minimal amount compared to using whole eggs, and with all the emulsifiers and fats in a yolk, they contribute more of a shortening and tenderizing function than whole eggs.
  • Baked goods made with yolks only are richer and more tender than those made with whole eggs. Less water equals less gluten development, and the fats in the yolk weaken the gluten that is present.
  • Yolks contribute a lot of color, much more so than using whole eggs. Baked goods made with yolks only have a lovely deep golden hue. Their protein content assures lovely browning thanks to Maillard reactions.
  • Batters made with just yolks are rich and billowy and luscious, partly due to all the emulsifiers present in the yolks.
  • If the only difference between two batters is one is made with whole eggs and one is made with yolks, the yolky batter will contain more vitamins, fatty acids and trace minerals than the whole egg version.
  • Yolks add a mellow, “eggy” flavor to baked goods. Either you are a fan of that eggy flavor, or you’re not, so consider that when deciding whether to bake with yolks only. Yolks can also muddy the flavor of other ingredients, mellowing and muting them. Again, some folks like this and some folks don’t.

Egg Yolks as Emulsifiers

Another important function of eggs, specifically egg yolks, is that they contain several emulsifiers. One emulsifier in egg yolks you may have heard of is lecithin.

Emulsifiers are molecules that have one end that likes to hang out with fats and another end that hangs out with water. Add an emulsifier to a water-type/oil-type mixture, which normally would separate upon standing, and they’ll hang together. This means we can harness the power of emulsifiers in egg yolks for the following purposes and more:

  • Egg yolks join the fat in butter with the water in milk and egg whites to create a smooth cake batter.
  • Adding a touch of egg yolk to a vinegar and oil mixture (heavy on the oil), and you end up with a lovely emulsified mayonnaise.
  • Egg yolks join the water in lemon juice with the fat in butter to make a creamy Hollandaise sauce.

Recipes Containing Egg Yolks

Egg Whites

A chef using egg shells to separate whites from yolks into a white bowl. A carton of brown eggs sits in the background.
Separating the yolks from the whites changes the game considerably!Photo by rawpixel on Unsplash

The albumin or white of an egg contains 86% water, 12% protein, no fat at all and 2% minerals and such. When you realize whites make up two thirds the volume of the egg but only contain 1/3 the calories, it’s easy to understand why folks who are on a diet favor using whites only.

  • Baked goods made with whites only are pale in color, especially if they don’t contain any other “coloring agents,” either natural (such as spices) or artificial (like food coloring). If you’re going to make those rainbow cakes, start with a whites-only batter so your colors stay true.
  • While whites are mostly water, they have a drying effect on baked goods since all that water activates gluten without the tenderizing influence of the fat in the yolks. Most whites-only cakes (think angel food cake) rely heavily on the addition of extra sugar to tenderize the structure and bring moisture to the final product.
  • Whites don’t contribute to the overall flavor of whatever you’re making. This means that the flavors you do introduce are more pure tasting since yolks bring a mellowness.
  • There are no emulsifiers in egg whites, so batters containing whites only as well as other liquids are more prone to breaking or having a slightly curdled look to them. Angel food cake is an exception because the only additional liquid in an angel food cake is maybe a bit of extract.
  • While the color of the dough or batter is whiter, you should still be able to achieve a nice brown crust on whatever you’re making because of the protein in the whites and sugar. Again with the Maillard reactions.

Recipes Containing Egg Whites

Okay, I think that pretty much covers what eggs do in baking cakes and such.

You can find my discussion of the function of eggs in custards here.

What Can I Use In Place of Eggs? Are There Good Egg Substitutes?

I bake with eggs. I love all the roles they play in baking and cooking, and I love the flavor.

But for folks who cannot have them due to allergies or for people who do not eat eggs (broadly: vegans), there are some viable substitutes.

  • To approximate the flavor of eggs in dishes where eggs are usually the star (deviled eggs, and tofu scramble, for instance), you can sub in some black salt called kala namak. This salt is high in sulphur compounds and so can act as an egg flavor replacer. I would not suggest you use it in sweet dishes, though. NOTE: the salt is not black but more of a pink-beige color. I have no idea why they call it black salt.
  • To approximate the texture of eggs in cakes, you can use ground flaxseed mixed with water in a ratio of 1 Tablespoon ground flax to 2-3 Tablespoons water per egg needing to be replaced. Let it sit for a few minutes until it gets a little “gloopy,” like egg whites. TIP: in baking cakes where I want a nice, fine texture, I make sure the flaxseed is extra fine by whirring it up super fine in my blender.
  • You can also use aquafaba (the thickened water from canned chickpeas) as an egg replacer in both sweet and savory cooking and baking. The Kitchn has a great post on using aquafaba as an egg replacer.
  • Bigger Bolder Baking also has an excellent post about 7 common egg replacers to use in baking.

Some Interesting Egg Facts to Ponder

  • Eggs are one of the leading food allergens. When folks have an egg allergy, generally it is to one (or a combination of) the proteins present in the whites. I’m not saying that people with egg allergies are cleared to eat yolks, of course. I just find it interesting.
  • Eggs do not like really high temperatures. This is why we often bake custards in a water bath. The part of the batter that is submerged in the water (in a pan, of course) can never rise above the boiling point of water, or 212F/100C.
  • Eggs like gentle cooking, and the more slowly you can cook them, the more silky, creamy and sexy your custard will be.Have you ever had a baked custard that has a weird, grainy texture? This happens when the eggs cook too quickly, the proteins seize up tight and squeeze out all the liquid.And what are you left with? A nubbly, tweedy texture. Ew. I cannot tell you how many pieces of flan I’ve sent back. Sigh.
  • Grocery store eggs, at least here in America, have been washed so they’re all clean and pretty. This removes the protective coating that they naturally have, allowing them to pick up off-flavors in the fridge and to age more quickly.We get our eggs from our own chickens, and I can tell you that we are happy when they come out clean, but we don’t expect it. Either way, clean or not, we just wipe them off and keep them on the counter until we need to use them.We wash them right before use, thus protecting the coating on them which allows them to sit out at room temperature in the first place. (And this is all within reason, of course. It’s not like we’re using eggs that have sat out on the counter for months and months.)

I am sure I have left out some information about what eggs do in baking, so after reading all of this, please let me know if you still have any questions.

You can leave them here in the comments or shoot me an email. Either way, I’m happy to help, especially if helping one can help all figure out how eggs function in baking.

5 golden stars for rating recipes

Because knowledge is power, friends. Learn how ingredients function–how eggs act in baking and cooking, in this case–so you can make them do what you want them to.

Thanks for spending some time with me today. I appreciate it.

Have a lovely day.

I did know most of the information presented here, but I want to credit some outside research from my main textbook in culinary school.

Professional Baking, 4th Edition, Wayne Gisslen, pp47-50

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  1. Hi Jennifer:
    Do you know why some powder flavors such as unsweet cocoa do not work when you add it to egg whites when you try to make french style meringues. I used the unsweet cocoa from Girardhelli and after adding it to the egg white I lost the foam peak making totally flat and liquidy.

    1. That’s a good question. I believe it has to do with the fat content of the cocoa powder. Egg whites don’t love fat. It will inhibit the formation of the foam, and worse as you found out, it can break down a beautiful foam.

      You could try adding the cocoa powder at the very beginning of mixing–along with the sugar. It may take longer to whip up the foam, but once it forms, it should be fine. Also use a cocoa powder that has a lower percentage of fat in it. That usually means using a cheaper grocery store brand over using a more expensive, premium brand.

      I hope that helps, Sergio.

  2. Hi there!
    Thanks for the detailed post with percentage composition of yolks and whites.
    May I know if there’s a good substitute for whole eggs using water/soymilk + oil (Based on the percentage compositions)?


    1. I will do the math later–headed out the door–but I wanted to at least start to answer your question. I think you’d need the viscosity as much as the fat. Maybe adding finely ground flax to your mix would work? Or even use aquafaba/flax. Is the recipe you’re trying to sub for super exacting? I mean, would it suffer if you didn’t have the exact water:fat ratio you would with an egg?

      1. Okay, math: complete! If you’re wanting to sub water/soymilk/oil for an egg, shoot for 47 grams of weight per egg. For each egg, allow 6 grams of oil. For body, I would add 2 teaspoons of finely ground flax (14 grams) leaving 27 grams (roughly 1 ounce) of water/soymilk. I hope that helps!

  3. I find your web site very informative. It is a pity that too often recipes do not specify egg size.
    I have a situation. I am making scones and some recipes call for “0” eggs some for 2 eggs. If I use eggs what size based upon a a flour requirement of 2 lbs of self rising flour.
    This is my second request. I hope you will have time to respond

    1. Hi, Richard. I must not have seen your earlier question, so thanks for asking again so I can help! I have never used egg in scones or American biscuits before. I turned to a short but interesting discussion from years ago on Chowhound regarding whether or not to use egg in a scone dough. You can find it here: The short answer seems to be that egg will add a touch of richness and may also add to leavening, making for a lighter scone. I do think at the end of the day, you can choose to use egg or not and your recipe will not suffer, especially as you’re using self-rising flour which is well balanced for optimal rise. For 2 pounds of self rising flour, I think you can add up to 4 eggs as long as you reduce the amount of other liquid accordingly. I’m basing this on 1 egg per roughly 8 oz by weight of flour. I hope this helps. It will certainly at least give you a starting point for further experimentation. Thanks again for the question, and I’m glad you enjoy the site. I really appreciate getting feedback from readers. Take care!

      1. Hi, what is the purpose in seperating egg whites and yolks during mixing , why not just add in all in one shot?

      2. Hey, Fern. If the recipe calls for separated eggs, it’s usually because you mix in the yolks with the rest of the ingredients and then beat the whites into a meringue to fold into the batter at the end. This provides additional lift for leavening. Hope this helps. 🙂

    1. That’s a good question. I think it’s probably because chicken eggs are overwhelmingly the most prevalent egg used in baking and cooking in the US. Chicken eggs have a particular balance of water, protein, and fat, and because we know so much about them, we can predict how they will behave in recipes. Other eggs have larger yolks and/or less water and protein. I only have limited experience with eggs other than chicken eggs, but I do know that duck eggs are almost all yolk with very little white, plus they weigh more than chicken eggs. To get the same results with duck eggs in a recipe written for chicken eggs, you’d have to make a lot of allowances for adding more liquid and perhaps reducing the fat some because duck eggs are proportionally so different from chicken eggs. I hope that helps to answer your question, Nidhi.

    1. That’s a great question. I’m guessing you are asking in relation to yeast breads. Please let me know if it’s a broader question. In breads, eggs are considered an enrichment, adding fat and softening the crumb. In the case of an English muffin, we’re looking for a nice chew and a firm crumb that can hold up to the butter and jam. In general, if you see 2 bread-type recipes and the only difference is that one has an egg and the other doesn’t, the one with the egg will be somewhat softer (less chew) and a bit more tender (less sturdy) than the one without.

  4. Thank you for an informative article about eggs. I do have a question. I have been trying to bake a cake that calls for 12 eggs, tapioca flour, coconut milk, sugar, and single acting baking powder. Bake at 350 degrees.

    I was able to successful bake the cake one time. The rest of the time they deflated when I take the cake out of the oven.

    The instructions said to gently whisk the eggs and avoid creating bubbles in the whites. This creates a big bubble rise effect when baking causing deflation when done. This last attempt, I tried to avoid creating bubbles when mixing the eggs. However, the bubbles showed up even before I mixed it. As the result, the cake deflated and I failed again.

    I am not sure what I did wrong. In your article you mentioned the temperature of the eggs is important. I am wondering if I need to leave the eggs out in room temperature before I use it. Will it make a difference?

    Also does the single acting baking powder has anything to do with it? Any thoughts on the Double acting baking powder? Thank you in advance for your help his.

    1. Hey there, and thanks for your questions.

      First, a caveat: I don’t have any experience baking with non-wheat flour, so all my advice will be based on wheat flour, hoping that it will be “transferable” to tapioca flour. I will also refer you to some Gluten-free baker friends who might be better able to help.

      Can you think of anything/s you did differently after the first time you made this cake? It seems to me that 12 gently whisked whites would be too heavy for the tapioca flour to support. My thought would be to make sure you whisk the egg whites to medium peaks and then fold in the rest of the ingredients (sift flour and baking powder together, whisk whites plus sugar to medium peaks, mix coconut milk with flour mixture, whisk in 1/3 of the egg whites then fold in the rest. Pan and run a knife all through the batter to get rid of any air pockets and then bake as directed. I’d recommend a 2-piece tube pan–NOT a non-stick one–and cook it upside down so it doesn’t deflate while cooling. The cake sounds a bit like a traditional angel food cake, and that is how I’d make one of those.

      I would definitely make sure the chill is off the eggs. They don’t necessarily have to be at room temperature, but you do want them warmer than fridge temp–say about 68F or so.

      In this application, and just guessing that there is not much coconut milk in the recipe, I think single acting baking powder is fine as long as you work quickly once it’s added. Double acting would give you a bit of insurance though, since the reactions occur once when wet and then again when heated, so you would get extra “oomph” out of you rise if you use double acting. I don’t think it’s a deal breaker though.

      For more information on baking with non-wheat flour, talk to the best expert I know, Janice Mansfield. You can find her on facebook here: or go directly to her site here:

      Hope this helps, and let me know how it goes! Also, if you have a sec and you have a link, please share the recipe so I can see the ingredients/amounts and procedure. Thanks!

  5. Hello,

    I came to your website looking for information on what is the function of eggs in puddings. For what I understood it make it ticker, am I right? Actually I am trying to make my pudding vegan and what I had noticed is that egg is usually removed but nothing else is add to substitute it. I was thinking if I could add something in place of the eggs to make my dessert more pudding like. Any ideas? In Spanish they call pudding when it has eggs, without eggs is a whole different recipe.


    1. Honestly, you really can just leave the eggs out. If you are looking for a particular consistency in your eggless pudding, you can experiment with different types of starches that you use for thickening. I generally go with 1 Tablespoon of cornstarch or flour per cup of milk, but you can use more or less or even experiment with tapioca or arrowroot. You can also sub in some heavy cream for part of the milk to bring back some of the richness you lose by leaving out the egg. Hope that helps!

    1. That’s a good question. Sometimes they act as both, as in an angel food cake or a souffle. Other times, they act more as a binding agent or as a leavener. Look at how the eggs are added to the batter/dough, and you will get a good idea. And remember that eggs always have all those properties at the same time, so it’s a matter of degree.

      If you whip the eggs, chances are you’re looking for more leavening. If you just stir them in and chemical leaveners are also present, then you’re looking at eggs as more of a binding agent. They also will lend some richness and fat because of the yolks. Eggs are fascinating!

      I hope this has helped some. Happy to try and answer any other questions or to clarify more if I haven’t quite answered your initial question, Jacqui. 🙂

    1. Much as in cake–they provide structure and maintain moisture. Since brownies are already brown, the browning properties don’t really factor in very much. Eggs are also what give that paper thin crackliness to the tops of brownies. Yum!

    1. That’s a great question. Unfortunately, since eggs perform so many different tasks, there is no one universal substitute. A good sub in creaming method cakes is a flax egg. Texture-wise, I find even store bought ground flax to be too coarse in a butter cake, so I whiz mine up in a blender to get as fine a powder as I can. Then each egg called for = 1 tablespoon ground flax and 3 tablespoons water. Stir together and let sit until a bit gelled.

      I know there are other subs in other types of recipes including using extra leavening or applesauce, but I’ve never used those. I’ll look up some info for you and either edit this reply or shoot you an email.

  6. Hi! Can i use egg yolks in a bread recipe as water. I wanted to make a more eggy taste bread. The only solution i can think of is lessen the amount of water and add more egg yolks. Is that posible? The liquid in the recipe calls for 300 grams water, can i make it 200 grams water and 100 grams egg yolk instead? Thanks

    1. Great question. You can’t really use yolks in place of water because even though they’re liquid, they don’t contain much water. That doesn’t mean you can’t enrich the dough you’re already using with some egg yolk. You most likely won’t even have to adjust the amount of water. You might want to take a look at some existing recipes for egg-enriched breads such as challah or brioche, study the proportion of ingredients and then apply them to your recipe. Hope that helps!

  7. Not really a comment, but a question. I’m curious as to your preferred egg-substitute in cake/cupcakes, if you have one. My child is allergic to eggs. I know/tried: applesauce, ground flax seed with water, yogurt. Cannot try banana because she’s also allergic to bananas. I have tried and like the chocolate egg-free cake made with vinegar and baking soda, but I want to sub something in a strawberry cake recipe. Thank you.

    1. Oh, I really wish I could help you, Rose, but I just don’t know enough about it. I will refer you to a couple of my vegan blogger friends. They will be better able to help you than I will: You may also want to look at this recipe. It’s made gluten-free too, but it’s a strawberry cake that uses the baking soda/vinegar combination so it may very well work for you even if you sub wheat flour for the gf flours: Hope this is of some help to you!

      1. I’ve not heard that one before, Victoria–thank you! How do you use it as a sub, because isn’t it just like whole wheat flour? Or does it act sort of like a flax egg when you mix it with water?

    1. I saw you had signed up, and I’m so pleased, Anton! Hope you enjoyed the ebook. If you feel called to write a short testimonial, I’d like to put it on the download page and maybe even in the sidebar on the blog.

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