How to Halve a Recipe When It Calls for One Egg
How to measure half an egg (or a third, or a quarter), when using just the yolk works better, and how to adjust the pan and bake time for a smaller batch.
How Much Is Half an Egg?
In the US, eggs are graded by weight. A large egg must weigh at least 2 ounces (about 57 grams) in the shell. Out of the shell that's roughly 50 grams: about 33 grams of white and 17 grams of yolk. Eggs sold as large in most other countries are similar, though sizes are defined a little differently.
So half a large egg is about 25 grams of beaten egg. A third is about 17 grams, and a quarter about 12 grams.
How to Measure It
You need to mix the white and yolk together first, or you'll end up with more of one than the other.
- Crack the egg into a small bowl or cup.
- Beat it well with a fork until the white and yolk are completely blended and slightly foamy.
- Put your mixing bowl on a scale, set it to zero, and pour in 25 g. No scale? Measure 1 1/2 tablespoons.
- Save the rest. It keeps covered in the fridge for a day or two, and it's perfect for scrambled eggs or brushing on pastry.
When Using Just the Yolk Works Better
In cookies, brownies, and other rich, dense bakes, you can often use one whole yolk (about 17 g) instead of half a beaten egg. A yolk is about half water and a third fat, and it contains natural emulsifiers, so it adds richness and tenderness. The result is slightly richer and fudgier, and it's much easier to measure.
In sponge cakes, chiffon cakes, soufflés, or anything else that relies on whipped eggs for lift, stick with the measured beaten whole egg. The whites matter there, because their proteins trap air.
Don't Forget the Pan
Half the batter in the original pan makes a layer half as thick, and it will bake much faster and can dry out. Instead, pick a pan with about half the area of the original:
- 9 x 13-inch pan (117 sq in): use an 8 x 8-inch pan (64 sq in) or a 9-inch round (64 sq in).
- 9-inch round (64 sq in): use a 6-inch round (28 sq in), or bake cupcakes.
- 9 x 5-inch loaf: use a small 6 x 3-inch loaf pan or a few muffin cups.
- 12-cup muffin tin: fill 6 cups, and put a little water in the empty ones so the pan heats evenly.
Adjusting the Bake Time
If your smaller pan gives the same batter depth as the original, the bake time will be close to the recipe's, often a few minutes shorter because a small pan heats through faster. Start checking about 5-10 minutes early.
Keep the oven temperature the same. Test cakes with a toothpick in the center (it should come out clean or with a few moist crumbs) or check that the center reaches about 200-210°F (93-99°C).
Common questions
How many tablespoons is half an egg?
About 1 1/2 tablespoons of well-beaten whole egg, or 25 grams.
Can I just use a small egg instead of half a large one?
Not really. A US small egg weighs at least 1.5 oz (43 g) in the shell, so about 37 g out of it. That's about half again as much as half a large egg (25 g), so measuring is more accurate.