What's Really in Packaged Egg Whites?
If you're trying to incorporate more protein in your diet, especially at breakfast, egg whites can be a good option. They're essentially pure protein, have fewer calories than a whole egg and negligible fat. It can feel wasteful to crack open eggs and toss the yolks, however, so buying a box of liquid egg whites is a smart way to avoid that (and less messy, to boot).
But what exactly are liquid egg whites? If you've ever tried them, you'll likely have noticed that they're runnier than the egg whites you separate from a whole egg. Though the texture is different, both are essentially the same thing. Yes, those boxed egg whites literally come from cracking whole eggs, says Dan Kubiak, egg brand manager at Organic Valley—they're not some kind of manufactured product (whew!). And the only ingredient in the box is 100% egg whites, at least for the majority of brands out there.
How Are Packaged Egg Whites Made?
"It's an amazing process to watch how quickly a machine can crack [eggs] and separate them out into components: whites, yolks and some incidental amount that's a whole-egg mixture after having been broken," Kubiak explains. Organic Valley's 16-ounce Liquid Egg White container holds whites from the equivalent of about 10 large eggs (FYI: 3 tablespoons plus 1 teaspoon of liquid egg equals the white of one large egg.)
The reason that liquid egg whites pour differently than the viscous white you separate from a yolk at home is due to the pasteurization process (i.e., they're treated with mild heat to eliminate pathogens) in manufacturing, Kubiak says.
After the eggs are broken and separated, the whites go through pasteurization in stainless-steel tubes. This makes the egg whites safe to be packaged but slightly changes the consistency, he adds. While this doesn't impact the nutrition or taste of liquid egg whites, it can make them not as easy to whip as whites from eggs you break yourself—especially if you're making a recipe where fluffy egg whites are key, like angel food cake.
While the whites get all the glory and their own packaging, those mighty yolks don't go to waste. Organic Valley sells its leftover yolks to what they call ingredient customers (manufacturers that use Organic Valley ingredients in their products sold to retailers, foodservice operators such as restaurants or grocery stores with their own private label), who use them to make things like ice cream or salad dressing, Kubiak says.
Egg Whites Vs. Eggs: Which Is Healthier?
Pure egg whites are widely considered to be one of the most bioavailable and digestible sources of protein, says Kubiak. They can be used anywhere you'd use a whole egg, including in omelets, scrambled eggs and baking. And because boxed egg whites are pasteurized, you can also safely add them to things like smoothies and salad dressing to up the protein content. Pasteurized liquid egg whites are also the secret to making edible cookie dough, as author and DŌ founder Kristen Tomlan writes about in her book, Hello, Cookie Dough.
One thing you want to watch out for is egg white "products" that might have other ingredients or fillers, like gums and artificial colors, says Amanda Baker Lemein, a registered dietitian based in Chicago. Always look for cartons in the refrigerated section that have only egg whites as an ingredient.
Before you go stocking up on only whites, though, consider what you're missing out on by omitting the yellow. "A whole egg is a very nutrient-rich food—[it's full of] vitamin D, choline and iodine, most of which is found in the yolk," says Lemein. "Using a whole egg means more micronutrients, but also some cholesterol and saturated fat, though neither of which are in high enough quantities to be concerned about."
When to Use Packaged Egg Whites
There is a time and place for using egg whites from a carton, egg whites from the shell and whole eggs, she says—so it's a good idea to have all three on hand. A carton of 100% egg whites is great for making muffins or waffles, as it can be easily measured for baking, Lemein says. When she's having eggs for breakfast, she often mixes one whole egg with a couple whites from the shell to make an omelet or egg sandwich. She also says that having an egg per day is "perfectly healthy," such as enjoying one hard-boiled over a salad.
When it comes to deciding which form of egg to use, "it really depends on what else is going on in the meal and what purpose the egg is serving," Lemein says. "In simple baking, it's really just used as a binder; while in more complex recipes, like a cake, you would probably want the entire egg to avoid messing with the end product's crumb or texture."