Using egg whites instead of whole eggs is a common substitution in baking for a variety of reasons. Here’s a look at what happens when you make this swap and how it affects texture, nutrition, binding, and more.
Texture and Volume Differences
Egg whites result in a lighter, airier texture compared to whole eggs. This is because the egg white provides volume, while the egg yolk provides fat and emulsification. Some key differences include:
- Cakes and cupcakes made with egg whites will have a delicate, tender crumb versus a richer, denser crumb.
- Meringues and angel food cakes rely solely on whipped egg whites to provide loft and structure.
- Omelets made with just egg whites tend to be fluffier and drier than those made with whole eggs.
When beating egg whites, they whip up into soft, billowy peaks thanks to the protein albumen. This allows air bubbles to be trapped, providing lift. Egg yolks do not whip up like whites do. So for baked goods that rely on air incorporation for leavening, egg whites perform better.
Nutritional Profile
Egg yolks contain the majority of nutrients in eggs. Using just egg whites significantly reduces the fat, calories, and cholesterol compared to whole eggs:
| Nutrition Info (per 1 large egg) | Whole Egg | Egg White |
|---|---|---|
| Calories | 72 | 17 |
| Fat (g) | 5 | 0 |
| Cholesterol (mg) | 186 | 0 |
| Protein (g) | 6 | 4 |
As you can see, all the fat and cholesterol are contained in the yolk. So egg white omelets and baked goods will be much lower in these nutrients. However, proteins and vitamins like riboflavin are still present.
Binding and Emulsification
One of the most important functions egg yolks serve in baking is binding and emulsification. The lecithin and fat in the yolks helps bind ingredients together for a cohesive batter. It also allows fats and liquids to combine and form an emulsion.
Without the yolk, baked goods may turn out drier and less rich. Egg whites provide structure thanks to proteins like albumen, but they lack the binding power of yolks. So you may need to supplement with ingredients like oil or yogurt to help add moisture.
Foam Stability
Egg whites are able to be whipped into stable, stiff foam that holds its shape. This provides leavening and lift in recipes like angel food cake, meringue, and souffles. The proteins in the whites unravel when beaten, then form new bonds once cooled which helps maintain the airy structure.
Yolks do not provide the same foaming ability, so using whole eggs in recipes relying on egg white foams may cause them to collapse or deflate. Stabilizers like cream of tartar or corn syrup can help maintain the structure if you want to use whole eggs.
Moisture Retention
Whole eggs help baked goods retain moisture over time better than just egg whites. The fat content in the yolks gives cakes and cookies a soft, moist mouthfeel. Egg whites provide moisture as they cook, but lack the staying power of fat.
Recipes made with only egg whites may turn out slightly drier, with a more sponge-like crumb. Adding baking spray or oil can help increase moistness when using egg whites.
Browning
Whole eggs promote more surface browning due to the milk proteins and fat in the yolk. Egg whites contain more water, so they do not brown as quickly when baking. If you want to achieve a golden color on biscuits, cookies, pie crusts, etc., whole eggs are a better choice.
For recipes where color is not as important, like angel food cake, egg whites can work just fine. Brushing surfaces with milk or egg wash before baking can also help items brown more evenly.
Cost Difference
Egg whites are typically more expensive than whole eggs per volume. As of 2023, on average:
- 1 dozen large whole eggs costs around $3
- 16 oz egg whites cost around $4
So you end up paying more for just the egg white portion versus the whole egg. However, commercial egg white products last longer unopened than fresh whole eggs. So the convenience may be worth the price.
Performance in Recipes
Here’s how egg whites perform in certain recipes compared to whole eggs:
- Cakes: Egg whites make a lighter, spongier texture, while whole eggs make a richer, denser cake.
- Cookies: Whole eggs result in chewier, more tender cookies. Egg whites can work but may spread more.
- Meringue: Egg whites are required for meringue. Whole eggs will not whip into stiff peaks.
- Quiche: Whole eggs make a creamy, set custard for quiche. Egg whites may cause a drier, puffier texture.
- Fried Foods: Whole eggs work better to coat and bind fried foods. Egg whites runny and drip off.
Converting Recipes
When adapting a baking recipe to use egg whites instead of whole eggs, here are some tips:
- Use about 2 egg whites per 1 whole egg
- Reduce oven temperature by 25°F since egg whites brown faster
- Add 1-2 tsp oil or melted butter per egg yolk omitted
- For binding, add about 1 tbsp starch (flour, cornstarch) per yolk replaced
- Boost structure by adding a cream of tartar or extra sugar
- Increase leavening agents slightly to account for missing yolks
The added fat and binding agents help make up for what is lost when omitting the yolks. Testing batches and adjusting the liquids and leaveners as needed can further improve the final results.
Conclusion
Egg whites provide lift, structure, and moisture in baked goods, but lack the fat and emulsifiers found in yolks. So they work best in recipes where a light texture is desired, like cakes and meringues. Using egg whites instead of whole eggs reduces calories and fat, but changes the nutrition profile. Adjusting other ingredients in the recipe can help improve moisture, binding, and browning when swapping in egg whites.