Baking recipes often call for eggs and butter to be at room temperature, but people often ignore this step. Find out why room temperature ingredients really do make a difference.

By Real Simple
Updated September 23, 2016

At room temperature, eggs, butter, and milk bond and form an emulsion that traps air. During baking, the air expands, producing light, airy, evenly baked treats. Batters made with room temperature ingredients are smooth and evenly incorporated. Cold ingredients don’t incorporate evenly to bond, resulting in dense cookies, rock-hard breads, and clumpy cheesecakes. Batters made with cold ingredients won’t come together smoothly.

Take eggs, butter, and other dairy products out of the refrigerator at least 30 minutes and up to 1 hour before baking. If you’re short on time, cut your butter into small pieces and microwave for a few seconds at a time, checking often, until they’re just malleable. Make sure to keep eye on it because microwaves vary.

Bring cold eggs to room temperature by placing them in a bowl of warm water for 15 minutes. Don’t use hot water or put eggs on top of a hot oven—this will heat them unevenly, and the whites will start to set.