Yes, You Really Should Use Room-Temperature Butter If a Recipe Calls for It—Here's Why

As a recipe developer and test kitchen manager for King Arthur Baking Company for over 10 years, I became very familiar with the questions home bakers would ask of the brand’s Baker’s Hotline: Why did my cookies come out flat and hard? Why is my cake dense? Why is my pie crust shrinking in the oven?

Questions like these not only motivated me to try to write better and better recipes but also prompted me to consider the variables of baking that can cause undue trouble for home bakers. To this day, as I consult with other baking brands and bake and develop recipes on my own, I reflect on these variables and their impact. One such variable that I’ve witnessed make or break baked goods is ingredient temperature.

It can be easy to overlook the temperature of your baking ingredients, when many baking staples come straight from your pantry. However, there’s a reason recipes often specify what temperature your butter, eggs and other refrigerated ingredients should be, whether “cold” or “room temperature.” In this article we’ll cover what “room temperature” (or sometimes “softened”) means, and why this term shows up in particular recipes.

Related: The #1 Baking Mistake You’re Probably Making, According to Claire Saffitz

What Does “Room Temperature” Mean Exactly?

First, let’s define what room temperature is. To do that, we look to butter, which is often the first and most temperature-sensitive ingredient we work with when we bake. When it comes to butter, most sources will tell you that room temperature is somewhere between 65°F and 70°F. Within this range, you should be able to press your finger into a stick of butter and meet just the slightest resistance. This test tells you that your butter is pliable (or plastic, as the baking pros say) enough to work with but not so soft that it will literally break (or separate) when you do.

Why Do Recipes Call for Room-Temperature Butter?

So why is it that we want butter to be pliable? Well, just about every recipe that calls for room-temperature butter (cakes, cookies and some muffins and quick breads) has you start with the “creaming” process. During this step you’re supposed to beat butter and sugar together until they become light, fluffy and more or less homogenous. It is essential for the butter to be at the correct temperature to achieve this step because only then will it stretch and expand as the mixer incorporates air. Your butter is what traps the air in your batter or dough, which is what results in lighter, more tender cookies, cakes, etc. Too cold and the butter won’t let the air in; too warm and the air will quickly escape.

Related: 19 Healthy Baking Recipes to Make This Weekend

Why Do Recipes Call for Room-Temperature Eggs?

Baking doesn’t end with the creaming process though, so let’s move on to what’s often the next step of these recipes: the addition of eggs. In just about every case, if your recipe calls for room-temperature butter, you want your eggs to be at room temperature, too. This is because butter is an emulsion of about 80% fat and 20% water and milk solids (or proteins). As an emulsion, butter is very sensitive to changes in composition and temperature. Adding eggs, which contain a lot of water, drastically alters butter’s composition—that’s the reason recipes usually tell you to add the eggs one at a time. Thus, you want to avoid a big fluctuation in temperature as well. Even just one cold egg can be enough to shock your beautifully emulsified and fluffy butter-sugar combination and cause it to break, leaving you with small clumps of condensed fat in a pool of eggy liquid. This broken emulsion is what results in flat, hard cookies and dense, coarse cakes, muffins and quick breads.

What About the Other Ingredients in the Recipe?

If room-temperature butter necessitates room-temperature eggs, it stands to reason that the ingredients that follow should be at room temperature as well. The last thing you want to do after carefully coaxing butter and eggs into emulsion is to risk breaking it by dropping its temperature with a subsequent cold ingredient. Milk (dairy or plant-based), sour cream, yogurt, cream cheese, etc. are all ingredients you should (and safely can) leave out on your counter for an hour or two (like butter and eggs) before adding them to your beautiful emulsion.

Related: Substitutions for Baking Ingredients

How to Quickly Bring Ingredients to Room Temperature

But what if you don’t have an hour or two to bring your ingredients to room temperature? There are some hacks you can use to gently warm butter, eggs and some of the other ingredients without inadvertently melting, cooking or altering them beyond repair.

A lot of sources will tell you that you can soften butter in the microwave. The problem with microwaves, however, is that they heat unevenly and rather intensely. This can result in butter that is perfectly softened in some places but too warm or too cold in others. My recommendation instead is to cut your butter into ½-inch cubes, spread those cubes out on a plate, and leave them at room temperature for about 20 minutes. This will ensure that the butter is evenly and perfectly softened in the time it takes you to preheat your oven, prepare your pan(s) and gather all your ingredients.

Getting eggs to room temperature is an even quicker task. Simply put your eggs in a bowl filled with tepid (bathwater-temperature) water for 5 to 10 minutes. In that time they’ll equilibrate to room temperature and be ready for your recipe when you are ready for them.

As for the other ingredients, anything liquid can be heated in a microwave in 15-second bursts (or gently in a pot on the stove). Ingredients like sour cream and cream cheese will do better with a similar technique to the butter: Spread them out on a plate or in a wide bowl to expose as much surface area to the air as possible.

Related: 6 Bad Baking Habits You Should Break, According to a Professional Recipe Developer

The Bottom Line

The general rule to remember when it comes to baking with room-temperature ingredients is to let butter be your guide. If your recipe calls for the creaming method, you know the butter—and, therefore, all your other ingredients—should be at room temperature. Also, if you’ve ever let cold ingredients stop you from baking before, know that within 20 minutes of prep time, you could be well on your way to your favorite cake, cookie, muffin or quick bread. There’s no excuse anymore!