When & Why to Use Room Temperature Eggs
Some recipes specify that the eggs or egg whites be at room temperature when added. However, for recipes that don’t specify room temperature eggs, use eggs straight from the refrigerator.
In the case of cheesecakes and other batters with a high fat content, adding cold eggs could re-harden the fat, making the batter appear curdled or lumpy, possibly affecting the texture of the baked product. To avoid this, remove the eggs from the refrigerator about 30 minutes before use, or put them in a bowl of warm water while assembling the other ingredients.
Recipes that involve beating eggs or egg whites, with or without sugar, into a stable foam – soufflés, meringues, angel and sponge cakes – also specify room temperature eggs. That’s because eggs whip up to a greater volume when they’ve had a chance to warm up a bit, 20 to 30 minutes. Because it’s easiest to separate whites from yolks cleanly when they are refrigerator-cold, this should be done when starting the recipe. Then let the whites stand at room temperature while you prepare the baking pan, equipment and other ingredients.