Room temperature

Room temperature, in recipes, means about 20 to 22°C (68 to 72°F): the temperature of a comfortable kitchen. Recipes ask for butter, eggs, milk, cream cheese and sour cream at room temperature mostly in baking, because cold ingredients do not mix evenly. Some recipes also tell you to bring meat or dough to room temperature, or to serve a dish at room temperature.

How to do it

• Eggs: leave out for 30 minutes, or put them in a bowl of warm tap water for 5 to 10 minutes.
• Butter: leave out for 30 to 60 minutes, or cut into small cubes to speed it up. It is ready when softened: a finger leaves a dent without sinking in, and it still feels cool.
• Milk and other liquids: leave out 30 minutes, or warm briefly in the microwave in 10-second bursts.
• Cream cheese: cut into cubes and leave out 30 to 45 minutes.

How to tell it is done

The ingredient feels neither cold nor warm to your hand. Butter is about 18 to 20°C (65 to 68°F), cool and pliable but not shiny or greasy. Eggs no longer feel cold through the shell.

Why it works

Cake batters are emulsions of fat and water. At room temperature, butter is soft enough to trap air when you cream it with sugar, and eggs blend in without making the butter seize into lumps. Cold milk or eggs can harden the butter and break the batter, which leads to a dense, uneven cake.

Common mistakes

• Melting the butter in the microwave. Melted butter cannot hold air the way softened butter does.
• Leaving butter out too long on a hot day. If it is above about 24°C (75°F) it is too soft.
• Leaving perishable food out for hours. Keep eggs, dairy and meat out no longer than 2 hours, or 1 hour above 32°C (90°F), under USDA guidance. Between 4 and 60°C (40 and 140°F), food is in the danger zone where bacteria grow.
• Assuming your kitchen is 20°C (68°F). It may be much warmer in summer or colder in winter.

In recipes

"All ingredients at room temperature" is common in cake recipes. "Let the steak come to room temperature" usually means 20 to 30 minutes out of the fridge, which takes the chill off the surface; the center will still be cool. "Serve at room temperature" means neither chilled nor hot.