Eggs can be an incredibly versatile and useful ingredient, but can be a problem for those who can’t or don’t want to, eat eggs. Compounding that problem is the lack of any sort of “universal” egg replacement, as eggs can have different purposes within  a recipe.

If you are cooking a recipe, and need to make a substitution for eggs, the first thing you must figure out is what the egg is doing for the recipe.

Purpose of Eggs in a Recipe

Eggs generally provide one or more of the following purposes in a recipe:

• Provide moisture
• Add colour or flavour
• Act as a leavening agent
• Act as a binding agent
• Help emulsify ingredients
• Form the basis of the dish

To determine the egg’s purpose, look at the end result and the other ingredients. Ask yourself what is the critical element of this recipe. A custard, for example, likely does not need any sort of leavening agent at all, while leavening might be more important to a muffin.

Then, try to figure out which ingredient is doing the heavy lifting for that dish. If a muffin already has baking soda/powder, then it is unlikely that the egg is acting like a leavening agent. However, if that muffin recipe does not have many liquids, then the egg is likely adding moisture.

Once you’ve decide what the egg is doing in the recipe, it is much easier to determine what to substitute the egg with.

Eggs For Moisture

• Recipes that contain very little liquid except for the eggs are most likely using the eggs for moisture.
• If only egg whites are called for, it is unlikely that they are used to add moisture. Egg whites actually dry out baked goods.

Eggs can be an excellent way of providing a dish with much needed moisture. The best way to replace eggs in this way is to use ingredients with high levels of water. Fruit purees (ie., banana, apple and pumpkin) and sour-cream are usually excellent substitutes.

Just be careful, because these will impart a bit of their flavour into the dish, so make sure it is a complimentary flavour or that the other flavours will help mask your substitute’s. On the other hand, this might be a fun way to change up a classic recipe.

Eggs for Colour or Flavour

• Eggs used as a “wash” to coat breads or pastries are there to create a nice brown, shiny appearance. To achieve this, you can substitute milk, cream, butter or oil. Some will also use water. Milk browns nicer than cream, butter, or oil. To create extra crispy crust, spray lightly with water throughout the baking process.
• If eggs are used as a “wash” to help things stick to breads or pastries (think nuts, coconut, salt, etc.), milk works better than oil, butter or cream.

Some dishes use eggs as a main component of their flavour profile, and this can be trickier to replace. Some suggest various sulphurous rock salts are a good substitute.

We were able to find commercial artificial egg flavouring products, but these are only sold to industrial commercial customers. Who knows, maybe down the road we will see “Artificial Egg Extract” next to the Artificial Vanilla Extract in the baking section of the grocery store.

Egg as a Leavening Agent

• If the recipe calls for egg yolks alone, they are most likely not acting as a leavener. Yolks have too much fat.
• Whole eggs in cake, muffin and cupcake recipes are likely used as a leavener.

For some foods, especially cakes and muffins, eggs will act as a leavening agent to help the dough rise. You can replace this with a number of things, like baking soda and vinegar (mix 1 tablespoon of vinegar with 1 teaspoon baking soda).

One of the odder things I have heard suggested is to use carbonated water. However, you mustn’t over mix anything with added carbonated water, as it is the carbonation itself that acts as the leavening agent.

Eggs as a Binding Agent

• Eggs used in sweet or savoury dishes like cakes, muffins, meatloaves, and quickbreads are usually acting as binding agents.
• If a recipe also calls for flour or breadcrumbs, the eggs are usually also providing moisture. Using a substitute may require you to add a bit of extra moisture to compensate.

Some of the best things to use are finely ground flax or chia seeds, fruit puree or starches like potato starch. When using fruit, remember that this will change the flavour of the dish.

Egg as an Emulsifying Agent

• Egg yolks allow ingredients to emulsify because of their high fat content. If a recipe only calls for egg whites, then they are likelynot being used to emulsify ingredients.
• If the recipe calls for water-based ingredients and oil-based ingredients PLUS eggs, the eggs are probably being used and an emulsifying agent.

Emulsifying is very similar to binding, but it specifically refers to ingredients that cannot naturally combine. If you are trying to combine oil and water, they will naturally separate after a few minutes. If you have an emulsifying agent, however, you can combine them without them separating later. Finely ground flax or chia seeds, as well as tofu, can be excellent emulsifying agents.

Eggs as the Main Ingredient

Sometimes, eggs make up the bulk of the recipe. In these cases, it can be hard, even impossible, to successfully replace them. If eggs make up more than a third of a recipe, you may find yourself hard-pressed to replace the eggs with something else. Your best course of action in this case may be to simply find another recipe to make.

Swanson Vitamins created this wonderful infographic showing various egg substitutions. Use it when you come across a recipe that needs a substitutions. Once you find substitutions that work best for you, in specific situations, be sure to write them down for quick reference.

If you have discovered some great substitutions or tricks, let us and our readers know using the comments below.

References: http://www.wikihow.com/Replace-Eggs-in-Your-Cooking