Eggs are pretty amazing.. a multi-functional ingredient that can give so many different results when used in baking. It is important for us to know how individual ingredients function within our cakes or baked goods as we can then begin to adapt our recipe and find a suitable substitute if required.
Here are the top 12 functions of of eggs in baked goods:
1. Providing structure – eggs contain proteins, and proteins when heated undergo a process called coagulation. Essentially this is the bonding of proteins which creates a strong yet flexible structure. Without eggs, most cakes will collapse.. they are also very important in thickening creams and custards.
2. Aerating – Eggs help in the leavening process of baked goods because they produce a fairly stable form consisting of tiny air bubbles. It is these bubbles that fill with air and cause a product, such as a cake, to rise. Egg whites are particularly good at forming a foam and can be whipped to up to 8 times their volume- impressive!
3. Emulsifying – An emulsifier helps prevent fat and water from separating.. so when added to batters and doughs they bind the individual ingredients together. The main emulsifier in eggs is called lecithin, which I will discuss in full another time!
4. Adding flavour – Although the egg white doesn’t really add any flavour, the yolk certainly does as that is where all the fat is located, and fat provides flavour!
5. Adding colour – Again the whites don’t contribute here, but the yolk contains caratonoids which provide a yellow/orange colour to cakes and other baked goods. They also take part in the Maillard reaction due to the amount of protein and glucose (albeit small) they contain.
6. Adding nutritional value – Eggs contain a fairly high amount of protein, as well as a variety of vitamins and minerals such as Vitamin D. The carotenoids in the yolk are also antioxidants (lutein being the main one here!)
7. Delaying staling – Starch retrogradation is why baked goods such as bread go stale.. eggs interfere with this process!
8. Adding moisture – Eggs are made up of 75% water so will provide moisture to baked goods. However it is also important to bear in mind that they are structure builders, so can also make certain products tougher and drier- it’s all about balance!
9. Giving shine – We can brush beaten egg onto the surface of doughs (such as bread) to give them a shiny surface when baked.. an egg wash (particularly when made with milk) will also help give the finished good a golden brown crust.
10. Acting as glue – The stickiness of eggs means that they can be used as an edible glue to adhere additional ingredients to the surface of baked goods, such as seeds and sugar crystals.
11. Giving a smooth texture to confectionery – For example, ice cream often contains eggs because the fats, emulsifiers, and proteins that they contain interfere with with sugar and ice crystallization, resulting in a smooth and creamy texture.
12. Increasing softness in doughs – The fats, emulsifiers, and proteins interfere with the formation of gluten development before a product such as bread is baked, so this can give it a softer texture.
So there we have it, 12 main functions of eggs in baking.. now you will understand how versatile they are!