Function of eggs in baking, their many uses and why we use them.
Function of eggs in baking. Eggs are a fundamental in baking. They perform a host of different functions in different bakes and it’s important to understand when and why to use them.
In the grocery store there are often many verities of egg available, duck, quail and chicken are just a few of the available verities. They also come in many different sizes and it’s important to remember that unless otherwise stated, when a recipe calls for an egg, it means a large chicken egg. This is crucial to remember as buying extra large or small eggs with throw off the ratio of the recipe and won’t yield the desired result.
What’s in an egg?
If you crack open an egg, you’ll see that there are 2 main parts inside. The round yellow yolk suspended in the transparent “white”. The white is made up almost entirely of proteins and water whereas the yolk is comprised of nutrients, vitamins and fats.
People often mistake the little white straggly strand that floats around in there for what would develop into a chicken. This little strand is called the chalazae and it keeps the yolk suspended in the white, anchoring everything to the side of the shell. Most bakers leave this in, although some do prefer to remove it when making things like custard.
Your average large egg weighs around 56g. This breaks down into roughly 28g of white, about 18 g for the yolk and the rest for shell. Not all eggs are equal though, you will find that with some brands the yolks are small or larger. It’s all about finding the right eggs for your bake.
Often recipes specify eggs by weight, often asking for 100g of egg whites instead of the number of eggs. This is a good indicator that precise measurements are important in the recipe. If you don’t have a kitchen scale you can use the general weights for whites and yolks given above.
Function of eggs in baking
Eggs play an important role in all aspects of baking from cakes and cookies to meringues and custard. They create structure and stability, they help thicken and emulsify, they add moisture to cakes and other baked good and can even act as glue or glaze.
Function of eggs in baking – fat
Egg yolks have a high fat content and excellent emulsifying ability. Recipes that call for the yolk only typically do so because of this. The fat within the egg yolks provide your bakes with a rich flavour and silky texture.
As an emulsifier, egg yolks bind together water and oil. This helps bind together the liquid and fats in your recipe preventing the mixture from separating. This process aids in evenly distributing the liquid and fat throughout the mixture resulting in smooth batters and velvety custards.
When egg yolks are heated, the proteins unfold and fuse together. This is a very delicate process and needs to be done gently over a low heat. Too much heat and the mixture will curdle, but a nice gentle heat, egg yolks have the ability to thicken sauces and custards.
Function of eggs in baking – foam
When egg whites are used separately from the yolk, they perform a very different function. When whipped using either a hand whisk or an electric the whisking action incorporates thousands of tiny air bubbles into the egg. This creates a fairly stable foam this is used to make meringue or soufflé.
When used in cakes or soufflé the egg acts as a leavening agent. When cooked the air bubbles that were trapped in the egg start to expand with the heat causing the cake to rise without the need for baking powder or yeast. Sugar is added to egg white when making
Function of eggs in baking – whole egg
By using the whole egg in your recipe, you are getting the best of both worlds. All of the properties of the white and the yolk are still present they just don’t work quite as well as if they were separated. Often you need both the emulsifying power of the yolk and the lift and lightness the whipped white provide.
Whole eggs aren’t as good a just the yolk at emulsifying, but they are still excellent binding agents. They are used in all kinds of bakes to bind the ingredients together. Remember oil and water don’t like to mix so you need something to bind the two together.
Eggs also firm up and solidify when heated, this provides structural support to delicate desserts. When mixed with sugar, eggs help trap and hold air. Much like when egg white is whipped, when beaten with sugar thousands of tiny air bubbles form to give the finished product lift and to keep it light.
Function of eggs in baking – tips and tricks
Coagulation is what happens when you cook an egg. When raw eggs are exposed to heat and solidify, we call this coagulation. Eggs begin to coagulate at 60C, which gives light to the saying you could fry eggs on that, when it’s a hot day. When eggs are cooked at too high a temperature or for too long, they over-coagulate or curdle. This results in grainy custards and rubbery cake.
Unless specified, always assume that a recipe calls for room temperature eggs. Egg yolk binds and emulsifies better at room temperature and the whites also whip better. I personally don’t keep eggs in the fridge anyway but if you do, take them out of the fridge a few hours before you use them.
Get cracking – A few tips on how to crack an egg like a pro.
Don’t use a knife to crack an egg. This forces small pieces of shell into the egg. Shell that you will have to fish out later. Instead hit it against the counter top or the side of the bowl.
If you do get shell in your bowl, use another, larger piece of shell to fish it out. The sharp shell will pierce the egg easier to collect the rogue piece of shell.
Crack your eggs into a small bowl first, one by one. This way if one is bad you haven’t ruined your whole recipe. I’ve seen a chef with nearly a hundred eggs cracked into a bowl and one of the last ones was bad, ruined the whole batch.
And there you have it the function of eggs in baking. Let me know in the comments if you like this type of post and if so what you would like to see next.