Eggs and Their Use in Baking

I had a great question on my blog recently asking about the size of eggs I use. So I thought it might be useful to write up a post all about eggs and their use in baking. Let’s be honest, I am a complete science nerd when it comes to baking! I love diving deep into the ‘why’ behind each ingredient so we’ll touch on that a bit and also talk about substitutions and why I choose certain ones over others in egg-free and vegan recipes.

The Purpose of Eggs in Baking

Eggs are generally one of the main components of any baked item, alongside sugar, flour and butter. But do you know why eggs are used in baking? From a scientific viewpoint, there are 6 most common reasons:

• Moisture
• Richness
• Colour
• Binding agent (structure)
• Leavening agent
• Flavour

Does Size Matter?

I’m a huge fan of precision baking as I prefer to bake by weight to better control the outcome of my baked goods. But, and here’s the big but, when it comes to eggs, I’m ok with going on the assumption that most eggs of the same size weigh roughly the same, give or take a few micrograms.

The larger the egg, the more moisture, richness, and leavening it will add. For example, let’s take a cake recipe that uses 2 eggs. If you found that the cake turned out denser than you’d hoped, you can add an extra egg next time. Fewer eggs in recipes usually create a denser, more fudgy consistency. I’m thinking specifically of brownies when I’m writing this as they don’t tend to include more than 2 eggs. You can also use larger eggs in a recipe to give a more cakey, springy consistency. (large instead of medium, extra large instead of large etc). It’s also why cookies usually only use 1 egg (or none at all), as they are a drier baked good.

Egg Sizes

I usually use large eggs in my baking, which are equivalent to approximately 50g once removed from their shell. Did you know that the difference between egg sizes isn’t that great? In most of my recipes, you can use the next size up or down without noticing too much of a difference. Plus I will always mention substitution recommendations for an egg-free version.

Medium eggs are about 1/4 tsp less in volume than a large egg. What this essentially means is that there will be less liquid and marginally less richness to your baked good. Almost to the point that you wouldn’t notice unless you are using a recipe that is full of eggs where the difference soon adds up. A great example is some of my traybakes which use 4 eggs to help create their fluffy texture.

Extra large eggs – I’ll be honest that I’ve never baked with extra large eggs. Mainly because they are more expensive and large eggs tend to be on sale most often. That being said, extra large eggs will have slightly more volume than large eggs, about 1/4 tsp, and can be used in recipes. You may need slightly more flour to balance out the extra moisture in some recipes, like cookies, but for most other recipes it’s not a deal breaker.

Remember that this is a general guide to sizes as eggs are not all created equally. And that’s exactly as it should be if you ask me! You also may find some slight variation in the sizes, especially if you prefer to use farm fresh eggs or have your own chickens (that’s my dream one day!).

For some great egg-rich desserts, check out these recipes:

• the perfect butterscotch traybake cake
• my delicious frangipane-filled cherry bakewell tarts

Egg Storage Tips

There is always a great debate about whether eggs should be stored in the fridge or not. I’m from the UK originally where you will find eggs stored outside of the fridge sections in grocery stores. It is also common for people to store them in a carton or egg holder on the kitchen counter at home. Yet in Canada (where I now live) they are always stored in the fridge. In fact, it is recommended by Health Canada that only refrigerated eggs should be purchased and eggs should always be stored in the fridge and used by the date stamped on them (or on the carton).

But did you know that there’s a great way to check whether your eggs are fresh enough to use? I store mine in the fridge and if they are not used within the recommended date, I always test them to check their freshness. You’d be surprised how long eggs stay fresh! All you need is a jug of room-temperature water and some eggs.

Substitutions

There are lots of great alternatives that you can use for eggs in baking, once you are familiar with what the egg is actually adding to the recipe. One of the most important parts of my role as an experimental baker is to work out what each element of a recipe does so that I can work with the remaining ingredients to determine the most suitable substitution. In terms of eggs, it might be richness, moisture, colour or even just to help bind the other ingredients together.

Apple Sauce

My go-to egg replacement when recipes ask for 1 or 2 eggs is applesauce. With one egg roughly weighing 50 grams, I sub with 50 grams of unsweetened apple sauce. I have also experimented with flavoured apple sauce when the baked good can handle extra flavours, like brownies or a fruit-based loaf like banana bread. Our kids are fans of apple sauce pots with hidden veggies so I’ll often throw one of those into a cake. Top tip: one snack-size apple sauce pot is usually between 100 and 110 grams so I just add the whole pot where 2 eggs are needed.

Apple sauce is not a great substitute for cakes which use 3 or more eggs, such as my coffee maple layer cake. In this recipe, which calls for 4 eggs, you would need to use 4 flax eggs (4 tbsp flax meal and 60 ml of water) or a combination of plant-based buttermilk to add richness and apple sauce (for moisture). This particular cake needs richness as well as moisture and if you just used apple sauce, the mixture would be too wet and wouldn’t rise properly.

Aquafaba

Aquafaba is the official name for the brine from a can of chickpeas that we would normally discard and has in recent years been heralded as one of the best natural substitutes for eggs. Personally, I think that it works better as an egg white substitute as it lacks richness but it will work in a pinch in cakes and cookies. I have had great success using aquafaba to make vegan meringues, vegan royal icing and vegan macarons. Use 50 ml or 1/4 US cup of aquafaba for the equivalent of 1 egg.

Avocado

Did you know that the superfood avocado is a great egg substitute in heavier baked goods like quick breads, chocolate muffins and brownies? It adds a creaminess to baked goods and healthy fats at the same time. And avocado can often be used to sub butter AND egg at the same time. I recommend only using it as a substitute in darker-coloured batters unless you want a green tinge to your baking. Chocolate baked goods hide both the colour and slight flavour of the avocado and help to keep everything nice and moist. Cocoa powder tends to dry out baked goods so the addition of avocado can really help to keep things fudgy. 1 ripe medium avocado (roughly 1/4 US cup) is the equivalent of 1 egg. Check out my vegan avocado brownies recipe to see why this ingredient works so well.

Banana

Overripe bananas work really well in muffins, cakes and quick breads where an egg is used for moisture and to bind everything together. 1 overripe mashed banana (roughly 1/4 US cup) replaces 1 egg. I normally only use them in recipes where 1 or 2 eggs are required. Any more and they can make the batter too wet and will overpower any other flavours.

Cornstarch

As a natural thickener when mixed with water, a cornstarch slurry is a great substitute when you need to make custards, pie fillings and cheesecakes. If you look at Bird’s Custard Powder for example, the main ingredient is cornstarch, yet when you make custard from scratch, you would normally use egg. To substitute one egg, use 1 tsp cornstarch with 3 tbsp (15ml) water.

Flax and Chia Egg

As I’ve mentioned, a flax egg is a great substitute in most baking recipes and I’ll often suggest it in my recipes. When you combine ground flaxseed with water, it creates a gloopy consistency which reacts similarly to eggs in baking. What I love about this option is that it is really inexpensive and easy to make. You can follow the same principles for a chia egg as well, using chia seeds.

To make a flax egg, stir 1 tablespoon of flax meal (ground flaxseed) into 3 tablespoons (45 ml) of water. Allow to rest for 10 minutes then use as directed in the recipe.

Plant Based Milk

I will often use plant based milk in my baking where the egg is being used purely to add richness and moisture (mostly in cookies, muffins, donuts and quick breads). Sometimes I’ll even add vinegar to curdle it to make buttermilk. Just add 15ml (1 tbsp) vinegar per 240 ml (1 cup) of milk, stir them let it for 10 minutes. This is a great egg substitute in pancakes and donuts and especially in red velvet baked goods where it adds an extra tang to the flavour.

Plant Based Yogurt

There are so many great plant based yogurts available from plain to flavoured and even greek style. I will often use a coconut or almond based yogurt in my cake recipes to help add another layer of creaminess and lightness. It also works really well to add moisture and to help bind the remaining ingredients together. My preferred ratio is 30g or 1/4 US cup of yogurt for 1 egg.

Commercial Egg Replacers

Numerous store bought egg replacements are available and while I have heard very good reviews about them, I personally haven’t used them myself. I prefer to use the other methods listed above as I always have them on hand. If you wish to use store bought alternatives, follow the directions on the packaging.

Testing different Substitutes

Check out this quick video showing the difference between eggs and two substitutes in my regular dairy free cupcake recipe. This is a great visual to show you how they react in a simple recipe.

Egg Substitutes Chart

This handy chart is a great reference when you’re unsure which substitute to use and how much to add to your recipe. Click here to open a printable version and then pop a copy on your fridge.

Egg free baking

Here are some of my favourite egg free recipes:

• perfect for any celebration – my best ever vegan vanilla layer cake
• Make the fudgiest chocolate treat with my avocado mini brownies
• kids will love my allergy safe strawberry lemonade sugar cookies
• decorate your own cookies with my vegan royal icing

So next time you’re reading a recipe and don’t have enough eggs in the fridge, or perhaps you want to change the texture slightly or sub for an egg-free option, I hope you’ll feel confident making changes based on my recommendations. Happy baking!

More Baking Science Tips

Like what you’re reading? Leave a comment below to let me know what your preferred egg substitute is. And don’t forget to check out more baking science tips here.

Thanks for reading.