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Have you noticed how most cake recipes call for eggs? But what if you don’t have eggs on hand, or can’t eat eggs? What if you’re trying to change the texture & flavour and you’re wondering whether you can do with more or less eggs?
In all those cases it would be helpful to know what the role of eggs in cakes is and what alternatives there are. There are a lot of solutions floating around on the internet. However, not all of them have been tested as well and even if they are, that doesn’t always mean it will work for you. So, we’ve done some testing for you.
What is the role of eggs in cake?
Before we start testing, let’s have a look at the role of eggs in cake. Why would you even use them in the first place? Your first reason might to add some colour to your cake, the dark yellow from the yolk darkens the batter and helps the colour if there’s nothing else with colour in there. The other roles of egg depend a bit more on how they’re used in the cake. Generally, eggs are used in one of two ways:
- The egg is not whipped up into a foam, instead, it is just mixed into the cake batter.
- The egg is whipped up until it is light and foamy, this can either be just the egg whites or a mixture of whites & yolks. It is then carefully mixed with the rest of the batter.
What eggs are made of
We will describe the role of eggs in both cakes, but not before defining what eggs are in some more detail. As you can see in the infographic below, eggs consist for more than 50% of water. For the remainder they consist of mostly proteins and fat.
The role of an egg’s moisture
Since an egg consists for the most part of water, that water will definitely impact the texture of your cake. The water will make a batter more liquid. When you make a cake batter you often look for a delicate balance in so called viscosity (thickness) of the batter. If the batter is too thin it won’t keep it’s shape and it will have trouble cooking and expanding in the oven. However, if a batter is too dry and viscous it will result in a ‘tight’ cake that does not expand as well.
In some cake types you have to whip up eggs (often egg whites) to create a light and airy foam. The role of the water here is to house all those air bubbles. The air bubbles are dispersed throughout the liquid, stabilized by the proteins (more on those later). In order to make a foam like this, you need enough water and again not too much nor too little.
When you want to replace egg it is easy to overlook this moisture component but be sure to correct for it.
The role of an egg’s fat in cake
Most of the fat of an egg sits in the yolk, so you really only add fat through eggs if you’re using the yolk. The fat in the egg yolk helps give a cake a richer mouthfeel, it won’t be as dry. If you’re making a foam, it is good to know that this fat can destabilize it, causing it to collapse!
Egg proteins stabilize cake
The proteins probably have the most advanced role of the three ingredients: they provide structure to a cake. The proteins set when you bake a cake and this helps hold together the light airy structure of a cake.
They have this role in both cake styles. However, for the second style, in which you whip up the eggs, they are even more important. When whipping up eggs you don’t just introduce air bubbles into the egg, you also force the proteins to unfold and arrange themselves around those air bubbles. The proteins are very good in stabilizing air bubbles (which is why they’re used in so many foams such as meringues). Once you place your foamy cake batter in the oven, the eggs denature and set. This solidifies the delicate foamy structure.
How to replace eggs in cake
So, when looking for an egg replacer we are looking for something that ideally takes over the role of all those three ingredients. In the case of cake style 2 (the one where you whip the eggs into foams) you want that extra ability to stabilize foams. Since that alternative is slightly more complicated, we will have a look at the first cake style: the one where you just mix in the eggs with the rest of the ingredients, no whipping to be done.
We just need something to replace the moisture, adds some richness and helps stabilize the cake’s structure. There are a lot of solutions out there for replacing eggs. We couldn’t test everything so decided to focus on four to start with. All of them are mentioned as one on one replacers for cakes quite often.
1. Bob’s Red Mill – Gluten Free Egg Replacer
This product contains potato starch, tapioca flour, baking soda and psyllium husk fiber. The starch and flour will help to set the cake whereas the baking soda will help give the cake some extra lift. Psyllium husk fiber is a special type of fiber made up of quite some hemicellulose. It can absorb a lot of water. As a result, when you mix this egg replacer with some water you will notice that it starts thickening up pretty soon. It is also this thickening effect that helps set the cake.
The main watch out when using this ingredient is that you let it pre-soak for a few minutes in the indicated amount of water to ensure that it doesn’t form clumps in your batter. The amount of water you need is quite comparable to that naturally present in an egg which makes that aspect pretty easy.
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Corn starch is quite commonly used as a thickener. You can use it in sauces, but also in dessert or ice creams. Corn starch will only thicken a liquid when it’s been heated. Therefore, a mixture of water + corn starch will stay very liquid in a bowl at room temperature. Once your cake is in the oven though it will start to thicken. Corn starch doesn’t contribute any fat so will lack that additional richness.
We made sure to add some additional water to the corn starch in advance to hydrate it (to prevent clumps) and to make up for some lost moisture of the egg.
3. Baking soda & vinegar
Last but not least, we tested a commonly mentioned solution of baking soda + vinegar. Various sources claim that 1 tsp of baking soda + 1 tbsp of vinegar can replace an egg. We were very doubtful of its success to start with. Baking soda is a great leavener, it will allow your cake to expand and rise in the oven. However, it does not contribute to the structure of your cake, nor does it add richness.
Nevertheless, we gave it a try. If you want to try this solution, be prepared to work fast. As soon as the amount of baking soda and vinegar come into contact the baking soda starts to react and bubble vigorously. So pour the batter into the moulds quick and place in the oven immediately.
4. Apple sauce
Apple sauce is often mentioned as being a good alternative for eggs. Apple sauce contains moisture as well as starches and pectins which can help set the cake batter. A disadvantage of the apple sauce is its flavour, in some applications that may come through, which isn’t necessarily desirable.
The results: best egg replacer
Of course, we will give you all the details of the experiments we did. We will come to that after giving you the results though!
First of all, none of the egg replacers worked as well as the egg. The egg clearly gave a different type of cake. However, if you’re open for something different, that doesn’t have to mean it’s bad.
Secondly, the vinegar + baking soda did not work at all. The cakes made with it tasted horrible (because of the alkalinity, they tasted metal like which is expected if you use too much baking soda). Also, they did not hold on to their structure, the expansion was way to much for the batter to hold on to.
Bob’s Red mill egg replacer was our runner up, after the eggs. It made a decently looking cake, but didn’t taste as rich. Then again, if that’s what you’re looking for, or if you modify the recipe by adding some more other fats for instance, that might be perfectly fine.
Last but not least, corn starch & apple sauce didn’t make horrible cakes, but it just didn’t do the job as well as the others. It might only work well with recipes specifically made for it, as opposed to recipes where we just replaced the egg. Also ,apple sauce did give a slightly softer texture than the corn starch (but missed some lift).
Testing egg replacers in an almond flour cake
Which egg replacer works best depends a lot on your recipe. Some replacers don’t work at all in one recipe, whereas they might work great in another. That is why we tested different recipes. In all our tests we tried to replace for the egg one-on-one, whether it was by following the manufacturer’s instructions, or using guidelines we found online or in books.
This first recipe uses very little regular flour and a lot of almond flour. Wheat flour actually gives a lot of support to a cake than almond flour, so the structuring role of egg would be tested. On the other hand, almond flour contains a considerable amount of fat which will help make a rich cake.
You can find the recipe at the bottom of the post, here’s what we used for the egg part:
- an egg
- 1 tbsp of Bob’s Red Mill egg replacer + 2 tbsp water
- 1 tbsp corn starch + 2 tbsp water
- 1 tsp baking soda + 1 tbsp vinegar + 1 tbsp water
- Egg gave best consistency & flavour
- Bob’s Red Mill rose well in the oven, but then collapsed about half way through.
- Corn starch didn’t really show any rise at all. It just stayed flat at the top, didn’t rise in the oven either and overall didn’t taste too great.
- Baking soda started out great, rising a lot in the oven. However, it started running over quite soon and ultimately collapsed completely, It couldn’t hold its own structure & weight and tasted very alkaline.
Finding an egg alternative for pound cake
A pound cake is made with equal (weight) quantities of eggs, sugar, flour and butter. There’s a lot more flour in this cake than in the previous one, so is expected to be a bit more sturdy.
Learning from the previous cake, we decided to let the baking soda & corn starch join forces. The corn starch needed some extra lift whereas the baking soda needed some extra support. Apart from that, we kept the experiment the same and added apple sauce!:
- an egg
- 1 tbsp of Bob’s Red Mill egg replacer + 2 tbsp water
- 1 tsp vinegar + 2 tsp corn starch + 2 tbsp water
- 50g of apple sauce (is approx. weight of the egg)
Results for the pound cake
- Egg gave best consistency and flavour, nice puff on top, rich flavour
- Bob’s Red Mill rose well in the oven, not as well as the egg, but different. It was actually a nice little cake, though a little more bland than the egg (less rich).
- Baking soda + starch: It still expanded way too much and the flavour was horrible, way to alkaline.
Testing egg alternatives for an orange cake
Last but not least we tried some alternatives in an orange cake. This cake has less butter than the pound cake, more moisture (orange juice) and a decent amount of flour. Also, it contains baking soda & powder already so shouldn’t be too dependent on the leavening power of the rest of the batter!
Replacing the egg was a bit more complicated since this recipe was actually designed for containing corn starch instead of egg. So, we had to balance out the amount of moisture. Since our experiences with baking soda hadn’t gone well at all, we decided to test the following scenarios (all calculated to 1 egg equivalent):
- Egg, no orange juice
- Apple sauce, no orange juice (50g)
- Corn starch (1 tsp) and 40ml orange juice
- Bob’s Red Mill egg replacer (1 tbsp + 40 ml orange juice)
Overall, this was probably the most similar batch so far! You can see that the egg cake raised most, however, it didn’t taste very different from the others. The cornstarch sample definitely had most orange flavour and the egg and apple sauce both lacked that flavour.
There are several other alternatives that are on our list to try, amongst them: bananas! Also, keep in mind that these solutions only work if your cake does not call for whipping up eggs. In that case you will need another more advanced alternative. Overall, we haven’t been too impressed so far, but we’ll keep on testing!