Egg is a key ingredient in French toast. It is used to help bind the bread cubes together and provide structure, richness, and flavor. The egg coats the bread, sealing in moisture and allowing the cubes to soak up the sweetened milk/cream mixture. When cooked, the egg sets and gives the French toast its distinctive custardy texture.
The Role of Egg in French Toast
There are a few reasons why egg is such an integral component of French toast:
Binding and coating
Eggs are excellent binders thanks to their protein content. When whisked together, the proteins unwind and link together to form a network that can hold ingredients together. This binding quality allows the egg mixture to thoroughly coat the bread cubes.
Moisture retention
Once coated, the egg mixture seals the pores on the surface of the bread. This prevents the bread from drying out while soaking up the sweet milk/cream and ensures the interior stays moist and tender during cooking.
Structure and richness
Eggs provide structure, richness, and body to French toast. As the egg cooks, the proteins coagulate to set the custard-like texture. The fats in the yolks also add flavor and a luxurious, velvety mouthfeel.
Browning and flavor
When cooked, the proteins on the exterior of the egg mixture brown and caramelize. This gives French toast its signature golden crust and toasted flavor. The Maillard reaction also develops deeper, more complex flavors.
How Much Egg is Used
The typical French toast recipe calls for:
- 2-3 large eggs
- 1 cup milk or cream
- 1/4 cup sugar
- 1 tsp vanilla extract
- Pinch of cinnamon
- 6-8 slices of bread
So for a full batch, a couple eggs are usually sufficient to properly soak and coat the bread. Too little egg may not bind or seal the bread well enough. Too much egg can make the French toast overly dense and eggy.
What Happens Without Egg
It’s possible to make French toast without egg, but the texture and flavor will be significantly compromised. Here’s what happens:
Lack of binding and moisture retention
Without egg as a binder, the milk/cream will struggle to adequately permeate and soak into the bread. The bread’s pores are not sealed, so it may soak up less liquid overall and become dry and crispy when cooked.
Falls apart easily
The interior of the bread won’t hold together as well. French toast without egg tends to fall apart more easily when slicing or eating.
Dense, soggy texture
While the center may be dry, the exterior is more likely to get saturated and soggy without the egg to add structural integrity. The texture may become overly soft and dense throughout.
Less rich flavor
The egg yolks provide a richness, creaminess, and sweetness that would be missing. Non-egg French toast often tastes flat, dry, and woefully lacking in flavor.
Paler color
Browning and caramelization during cooking will be reduced, resulting in a pale color versus rich golden brown French toast.
Suitable Egg Substitutes
If you don’t have eggs, some possible substitutions include:
Egg replacer powder
This vegan product mimics the binding, leavening, and moisture retention properties of eggs. Use 1 1/2 to 2 tsp per egg called for.
Flax or chia seeds
When mixed with water, they form a gel that works similarly to egg. Use 1 tbsp seeds whisked with 3 tbsp water per egg.
Banana or apple sauce
Pureed fruit has fiber and pectin that provides some binding. Use 1/4 cup per egg. May affect flavor.
Silken tofu
Blended tofu adds protein for binding. Use 1/4 cup in place of each egg.
Yogurt or cottage cheese
Dairy products work as binders too. Use 1/4 cup yogurt or 2 tbsp cottage cheese per egg.
However, these substitutions don’t perfectly replicate the binding, richness, flavor, and textural qualities of egg.
The History of French Toast and Egg
Eggs have likely been used to make French toast since the dish’s origins. There are a few theories about when and where French toast first appeared:
Ancient Rome
Some sources cite that French toast dates back to Ancient Rome. Recipes for “pan dulcis” or “sweet bread” describe soaking bread in milk and egg and frying – much like French toast.
Medieval Europe
In Medieval Europe, cooks may have also soaked stale bread in a custard-like mixture of egg and milk to rejuvenate it and reduce waste. The sweetened, eggy bread was then fried.
Early modern Europe
Versions of French toast became popular in European countries like France, England, Germany, and Spain in the 16th-18th centuries. Recipes often included bread, egg, milk, sugar or honey, spices and butter.
America
French toast made its way to America in the late 1800s as more recipes appeared in cookbooks. As eggs became more widely available, they became firmly established as a key part of French toast recipes.
So while milk-soaked fried bread has existed since ancient times, the use of egg to create the classic French toast likely emerged sometime in Medieval period and has remained integral ever since. The egg and bread combination proved to be a winning formula that became popular worldwide.
Cultural Variations
While standard French toast is made with bread, egg, and milk, many cultures have their own delicious variations:
Pain perdu – France
Literally “lost bread”, this is essentially the original French toast, made with stale bread. Brioche is also common today.
Torrijas – Spain
Spain’s take often uses stale bread slices soaked in wine or milk, plus cinnamon. Fried in olive oil and topped with powdered sugar.
Rabanadas – Portugal
Made with thick baguette slices dipped in milk, egg and port wine, then sprinkled heavily with sugar.
Eierkuchen – Germany
Germans prefer a thinner batter than typical French toast. The egg-soaked bread is fried in butter then served with powdered sugar or jam.
Eggy bread – Britain
British eggy bread is nearly identical to American-style French toast. Thick bread like brioche is used and topped with cinnamon or fruit.
Bomboloni – Italy
This sweet dessert is made by dipping dough balls in an egg mixture and frying. The puffed treats are dusted with powdered sugar.
So while techniques and flavors vary, the base of bread and egg remains constant in most global versions of French toast.
Ideal Bread Choices
French toast can be made with just about any bread. But some varieties are better than others:
Thick sliced bread
Thicker slices like Texas toast absorb more egg mixture and keep a pleasantly moist interior when cooked. Thin bread can dry out too much.
Hearty bread
Choose bread with more gluten structure like brioche, challah or sourdough to get French toast that holds together well with a tender crumb. Avoid flimsy white sandwich bread.
Stale bread
Using bread that’s a day or two old allows it to soak up more liquid as the egg mixture penetrates the dry pores. Very fresh bread may become too soggy.
Chewy crust
Breads with a crispy or chewy crust like baguettes get a pleasing textural contrast when made into French toast. The crust stays crunchy while the interior turns custardy.
Sweet bread
Breads with added sugar or milk like brioche already have some sweetness, which complements the typical maple syrup topping.
In general, choose a good quality egg bread or artisan loaf with some structure and crust to get the best results when making French toast. Stick with thicker slices too for more custardy interior pockets.
Science of Cooking with Egg
The science behind how eggs transform into delicious French toast help explain its importance:
Emulsification
The lecithin in eggs acts as an emulsifier, allowing fats and water to combine into a stable mixture. This creates the smooth, homogenous texture.
Coagulation and setting
When heated, the proteins in the eggs (mostly albumen) unravel and link together to coagulate into a solid setting the mixture.
Browning
The amino acids and peptides in the eggs participate in the Maillard reaction. This causes browning and the development of roasted, caramelized flavors.
Tenderizing
Papain-like proteases in eggs have a mild tenderizing effect on the bread, giving it a soft texture.
Binding and adhesion
Eggs act as a glue, bonding to the proteins in the bread dough and holding the slices together.
Density and richness
The fat droplets and lipoproteins in egg yolk contribute to the thick, luxurious mouthfeel.
So eggs provide many functions beyond just binding thanks to their unique composition of proteins, lecithins, enzymes and emulsifiers.
Nutrition
Eggs boost the nutrition of French toast:
High quality protein
The egg proteins help make French toast a satisfying high protein breakfast.
Vitamins and minerals
Eggs provide vitamins A, D, E, and B12, plus iron, zinc, selenium and other minerals.
Choline
Eggs are one of the best sources of this important nutrient for brain and liver health.
Antioxidants
Egg yolks contain lutein and zeaxanthin, antioxidants that support eye health.
Healthy fats
Mainly unsaturated fats in eggs can help moderate cholesterol levels.
So while French toast is an indulgent breakfast treat, the egg provides nutrients that make it more nutritious and satisfying.
Conclusion
Eggs are clearly the glue that holds delectable French toast together. Thanks to their binding, emulsification, coagulation, and flavor development properties, eggs allow the bread to transform into a hearty breakfast treat with a luscious creamy interior encased in a crispy golden crust. Egg also boosts the nutrition of French toast by adding high quality protein, vitamins, minerals and antioxidants. While French toast can be made without eggs, it just wouldn’t have the same rich taste and texture that makes it so crave-worthy. So for the best French toast around, don’t skimp on the eggs!