Everyone asks me how to replace eggs from a recipe, the answer is you simply cannot replace eggs and use the recipe as is! Why? To understand this question better, one must understand what an egg is and why is it an essential participant in most bakes!
A lot of you asked me to write about baking and to share knowledge, and here's a humble attempt at it.
All of us bake almost everyday, most of us with egg and others without egg! Here I wanted to talk about the science behind this one amazing ingredient and why it's a vital part in baking. And for others, I will soon talk about how to replace eggs in baking! So lets start ground up.
What is an egg?
An egg is some really exciting chemistry. Heating transforms no other food as dramatically as an Egg. One of the main components of whats underneath the shell is just water dispersed with sacks of proteins. The egg white is about 85 percent water and 10-12% protein and the egg yolk itself is about 14-16% protein and 50% water, this might slightly change from egg to egg. In yolk proteins are bound up with fat, which is why a raw yolk is lesser runny than the whites.
In addition to the taste and nutritional value, Eggs supply to a lot more value additions
• Emulsifier • Egg yolk contains a number of emulsifiers. Fat and water left to their own devices do not mix together, just like how the butter/cream floats on milk or how oil floats on water, the fat doesn’t coalesce, Which is why egg is added in Mayonnaise. Egg yolk proteins have amino acids of which a few repel water(Hydrophobic) and a few attract water(hydrophilic). When whipped with Fat and Water, the proteins uncurl allowing the water loving parts to attach with water, whereas the water repelling parts get attached to the fat. Thus binding water and fat into a homogenized solution. This interaction will keep the protein in shape until heat is introduced.
• Tenderizer • The fats in the yolk break the gluten in flour and help tenderize the overall bake. Also, yolks add richness, color and lusciousness
• Moisture • Proteins in the eggs are majorly amino acid chains, these chains are tightly bound and when heat in introduced the molecules start colliding, and when the temperature reaches about 65 degree celsius, the bonds start breaking apart and the proteins unfold and link to other proteins. As the proteins form these new strong bonds, the water that surrounded each protein molecule when the egg was liquid will be forced out and in our case this is absorbed by the cake batter, keeping the cake moist.
• Structure • This denaturing of proteins leads to coagulation, which along with the starches from flour help cake batter form the body and structure.
• Taste • In general, flavor of a cake is partly from the fats present in the yolks, which also help enhance other flavors bringing significant changes in the final taste profile of a cake.
• Aeration & Leavening. How does egg whites foam? Unlike water, when whipped bubbles form for a short while and break, wheras the egg proteins uncurl and stretch allowing the bubbles to stay longer and more importantly stable. Beaten eggs help to incorporate air into a cake batter and therefore aid in leavening.
• Thickeners • Now that we know what happens when heat is introduced to eggs, so lets talk about sauces and custards, which are not whipped as we want the proteins to denature and coagulate in an undisturbed manner. Like a cheesecake, crème caramel. So how does the eggs thicken? The same denaturing of proteins but with another liquid medium
Now that we have a picture of what an egg is and how it works, I will continue this post tomorrow with how we can replace this magical ingredient with vegan options!
If you are interested to read more about eggs here are some links that I found very helpful!