Eggs are amazing. Whole eggs—whites and yolks together—produce exquisite soft scrambles, perfect French omelets, and boiled eggs just the way you like them. But yolks and whites also perform separately (or in uneven numbers) to produce dreamy angel and chiffon cakes, rich custards, ice creams, and so much more. Every cook and baker should know how to freeze and thaw leftover yolks and egg whites separately for future use. It saves money (and guilt about throwing good food down the drain).
Egg whites are the easiest to store. Just freeze them in clean, grease-free containers; you can thaw and use them in any recipe that calls for egg whites. (I’d hesitate to use them in a cocktail, though—but maybe that’s just me wanting an impeccably fresh egg white in my Ramos fizz.) If you are willing to fuss, you can freeze each egg white individually in ice cube trays. If you freeze them in larger quantities, figure that each large egg white is about 1/8 cup, or 30-33 grams. Thaw egg whites on the counter—or in a larger container of warm water, if you are in a hurry, or overnight in the fridge.
Egg yolks are trickier. Once frozen, defrosted egg yolks will not blend smoothly with other ingredients—whisk as you might. Instead, they form tiny, stubborn globules. The fix is to condition them before freezing, with sugar syrup or salt—either way works, but you still have to observe a few precautions when you use them (because, regardless of the sugar syrup or salt fix, frozen yolks will still try to form those tiny globules). But only if you let them).
Thawed egg yolks that have been mixed with sugar syrup or salt can be whisked smoothly into other ingredients—but you must take care to whisk them first with the sugar (or some of the sugar) in the recipe, until smooth, before introducing any liquid. For example, if you make my Vanilla Ice Cream recipe, whisk the yolks with the sugar first, before proceeding with the recipe, as written. If there is no sugar, or the yolks are meant to be mixed with liquid first, whisk the liquid into the yolks just a few drops at a time, until you can see that the mixture is perfectly smooth, before whisking in the rest of the liquid.
Instead of making a quantity of syrup and then having some left over to store or throw out, I find it easier to dissolve the exact amount of sugar needed for the amount of egg yolks I am freezing.
For 4 egg yolks: Either use 3/4 teaspoon of corn syrup, or make syrup by putting 3/4 teaspoon of sugar in a very tiny cup or shot glass with 1/4 teaspoon of water. Stir and then microwave for 10 seconds, stir again and let stand for a couple of minutes or until the mixture is perfectly clear with no visible grains of sugar. Whisk the corn syrup or sugar syrup thoroughly into the egg yolks. You can divide the mixture into four parts or just freeze the whole amount. Defrost it for several hours in the fridge before using. If you have not frozen yolks separately, figure 15 grams (about 1 tablespoon) makes one large egg yolk.
Whisk 1/8 teaspoon of fine salt (no need to dissolve it) into 4 egg yolks. Whisk very thoroughly—until you see the yolks turn brighter in color and more translucent—before you freeze them.
Thaw yolks for several hours in the fridge—or on the counter, but only if the quantity is small enough so that the yolks don’t sit long at room temperature before you use them.
When deciding whether to use salt or sugar, consider the impact of 3/4 teaspoon of extra sugar—probably negligible—versus that of 1/8 teaspoon of extra salt. Of course, you can decide to subtract the amounts from the salt or sugar in your recipe, if you want to be exact.
How do you reduce food waste? Let us know in the comments!