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If butter is an ingredient in a baking recipe, it is never simply butter. It’s always specified whether it should be cold, at room temperature, or melted. The state of butter is important to achieve specific features in a baking good, like flakiness or fluffiness. While melted or cold butter sounds quite straightforward, what exactly is room temperature? One room might be 19°C / 66°F, and the other 24°C / 75°F, but will both of these temperatures produce equally good softened butter?
Is room-temperature butter and softened butter the same thing?
Just a quick clarification before we dive into the issue of room temperature. In recipes, the terms “room temperature” and “softened” are often used interchangeably when referring to butter. Essentially, they mean the same thing because, in simple terms, at room temperature, butter is soft.
What room-temperature butter is used for?
If a recipe calls for room-temperature butter, it means one of two things:
- You will whisk it and make buttercream from it;
- You will cream it with sugar for cake batter or cookie dough.
This article will focus on the process of creaming butter, as buttercream science calls for a separate article (coming soon!).
While creaming, butter gets softer, fluffier, and lighter in color, and all this happens because air bubbles get incorporated into the soft butter. When butter is at room temperature, it can hold those bubbles. In the case of a batter or dough, butter-trapped air bubbles will expand in an oven, resulting in a fluffy cake or a soft cookie.
If you try to whisk cold butter, beaters will smash it, but it will not get fluffy until it warms up enough. If you whisk melted butter, you may see some air bubbles on the surface, but they will not stay inside the butter. We need that mystic room-temperature butter for air entrapment magic to happen, but again, what exactly is room temperature?
Cold butter
Cold butter after whisking
Soft butter
Soft butter after whisking
Melted butter
Melted butter after whisking
Is there an exact room temperature that works best for creaming butter?
A quick search on Google and the answer is 18°C / 64°F. If you research deeper, you might get confused with a wider variety of temperatures. If 18°C / 64°F is the correct answer, does it mean that 19°C / 66°F is too warm and 17°C / 62°F too cold? Both physics and my experience suggest that this is not true. Material properties don’t suddenly change due to a slight change in the environment (for example, water doesn’t suddenly evaporate all at once when it reaches boiling temperature); the change is gradual. While there is definitely an optimal temperature for achieving the fluffiest butter, room temperature is actually an interval. So let’s head to the kitchen and find it.
The experiment: butter creaming temperatures
To check how butter temperature affects the final cake texture and rise, I baked 6 identical mini cakes, varying only the temperature of the butter. I used a basic pound cake recipe with the following ingredients:
- 50 g / 1.76 oz unsalted butter
- 50 g / 1.76 oz granulated sugar
- 1 egg (~50 g / ~1.76 oz)
- 50 g / 1.76 oz flour
- 1 g / 0.03 oz baking powder
The method involved creaming the butter with sugar, then adding a room-temperature egg, mixing until well incorporated, adding the flour and baking powder mixture, and then hand-mixing until combined.
I did my best to make all the cakes identical, except for the butter temperature. I paid attention to these factors:
- Creaming time: I used a timer to cream the butter and sugar for exactly 1 minute at the same mixer speed for each cake. This duration was sufficient to make 50 g / 1.76 oz of butter fluffy and very light in color.
- Baking pan: I used the same 10 cm / 4-inch anodized aluminum baking pan for each cake.
- Baking process; All cakes were baked in the middle of the same oven, one at a time, using the same baking program (heating from the top and bottom, no fan), for 35 minutes. Every batter version hit the oven immediately after it was mixed.
- Weather conditions: I baked all the cakes on the same dry summer day, to ensure that the batter was not affected by varying air humidity or something like that.
This approach allowed me to isolate the variable of butter temperature and observe its specific impact on the cakes’ texture and rise.
I selected 6 different butter temperatures with a 4°C gap between each for convenience. This allowed me to potentially add an additional smaller step in the exact middle, although I did not end up needing to do so. These were the temperatures before creaming butter:
- 12°C / 54°F;
- 16°C / 61°F;
- 20°C / 68°F;
- 24°C / 75°F;
- 28°C / 82°F;
- 32°C / 90°F.
At 32°C / 90°F, the butter begins to melt, so for this temperature, I melted the butter in a saucepan and then cooled it down to exactly 32°C / 90°F. I also “creamed” it with sugar, just to ensure that every cake was made the same way.
This baking experiment was the most fun and surprising one I’ve done so far. I started with a temperature of 20°C / 68°F, and the second one was 24°C / 75°F. When I removed the second cake from the baking pan, I was a bit surprised, and the idea, that I somehow messed up the 20°C / 68°F one struck my mind. But I went on with other versions and by the end of the day, I had an obvious infographicake on my table. No, I hadn’t messed anything up; the results simply demonstrated something different than what I had expected, and even more different from anything I have ever read on the Internet or, to be honest, anywhere. Let’s take a detailed look at the results.
Creaming process
To my own surprise, I was able to properly cream butter for every version, from 12°C / 54°F to 28°C / 82°F. At 12°C / 54°F, the butter was still hard and gave some resistance at the beginning, but it softened after about 10 seconds, and after a full minute, I had light and fluffy butter. The colder versions had slightly more visible sugar granules at the end, while the warmer versions appeared more even and were softer.
12°C / 54°F butter after creaming for 1 min.
24°C / 75°F butter after creaming for 1 min.
The batter
I didn’t even take pictures here, because the batter at its final stage looked almost the same every time. It was slightly thicker with colder butter, more fluid with warmer butter, and almost runny mixed with melted butter – basic logic here. It emulsified perfectly every time.
Cake texture
The texture of a baked cake was consistent between 12°C / 54°F to 28°C / 83°F: even, fluffy, with no unnecessary greasiness. 32°C / 90°F version had a slightly denser, less even texture with more significant air pockets. Also, plain logic here, whisking melted butter did not actually cream it, and only baking powder was responsible for the rise.
Taste
There were no noticeable differences in taste or mouthfeel; every cake tasted the same.
Rise
Finally, we reached the most interesting part: this formed a real-life infographic on my kitchen table, and you will easily notice it in the photos below. Comparing the rise of cakes, we are comparing rise no. 1 – how much the cake has risen evenly before it started to form a dome. Imagine I was baking cake layers for a layer cake, and I would have to cut off the domed part, leaving only the evenly raised part useful to me. Rise no. 2, or the highest point of a cake, is identical in almost every iteration (except the melted butter option). My theory is that the more air bubbles are trapped in the batter before it hits the oven, the more evenly the cake rises.
Batter mixed with 12°C / 54°F butter
Batter mixed with 16°C / 61°F butter
Batter mixed with 20°C / 68°F butter
Batter mixed with 24°C / 75°F butter
Batter mixed with 28°C / 82°F butter
Batter mixed with 32°C / 90°F butter
The cake rose the most evenly (the highest rise no. 1) when 24°C / 68°F butter was used. The colder the butter from this point, the bigger the dome, but the warmer from here – the dome is getting bigger again. 20°C / 68°F and 28°C / 82.4°F versions rose almost the same, with a slight favor to the 28°C / 82°F version.
Before starting this experiment, I was pretty sure that the perfect temperature would be above 20°C / 68°F, but I did not expect it to be that high. And I was very surprised to find that butter at 28°C / 82°F worked better than butter at 20°C / 68°F.
The room temperature interval
If we logically fill the gaps between the data we have after testing, the sweet spot or the temperature where butter can hold air bubbles best is approximately 24.5°C / 76°F (see graphic below). And the interval I choose to call a “theoretical room temperature” is between 21°C / 70°F and 28°C / 82°F.
But let’s get a bit more practical. Uniform 28°C / 82°F temperature in butter is very difficult to achieve. I did this experiment on a hot summer day and there was 28°C / 82°F in my kitchen. After the butter spent a few hours on the counter, the most I could get was 25°C / 77°F and to warm it to 28°C / 82°F I had to put it closer to an open hot oven. In an everyday situation, when butter sits for a longer time in a very warm kitchen, even if the inserted thermometer reads 28°C / 82°F, the surface of the butter is usually yellowed, indicating that it has already started to melt. Creaming partly melted butter does not give the best results, it looks slightly curdled and does not hold its shape. So going that far is actually risky.
The other thing I haven’t mentioned yet: butter temperature rises while creaming. Here is how the temperature changed after 1 minute of creaming each time:
Temperature before creaming
Temperature after creaming
Temperature change
12°C / 54°F
21°C / 70°F
+ 9°C / 16°F
16°C / 61°F
21°C / 70°F
+ 9°C / 16°F
20°C / 68°F
23°C / 73°F
+ 3°C / 5°F
24°C / 75°F
25°C / 77°F
+ 1°C / 3°F
28°C / 82°F
28°C / 82°F
No change
So in the case of colder butter, some of the creaming time was lost to warm and soften it up and air bubbles started to fluff the butter later than in the case of warmer butter. Theoretically, creaming colder butter for a longer time might yield the same results as creaming warmer butter for a shorter time.
While creaming 24.5°C / 76°F butter can give you the best results, the starting temperature is not the only factor and is not that important. The most critical factor is to have the most air bubbles beaten into your butter as possible at the end of the creaming process. Using a thermometer at every step or looking for a perfect creaming time for each temperature sounds like too much, even for me. This is why we judge from the look of the creamed butter. It has to be soft, fluffy, lightened in color, almost even in texture, and still hold its shape. I know, it’s pretty vague, but some things are best learned with practice. The two photos below could help you as a visual clue.
How to be sure your butter is at the correct temperature?
If you strive for perfection, use a thermometer. But you can easily judge visually and by touching your butter: If the butter gives in a bit when you press it but still holds its shape, it’s ready to be creamed.
Too cold
You could start from here*
Perfect
Still OK, but on the edge*
* Would not work to make buttercream.
But what if it gets too soft? If the temperature in your kitchen is, let’s call it, livable, something in between 20°C / 68°F and 23°C / 73°F, it’s simply impossible to get there. If it’s hot, watch it more carefully, but don’t worry too much. Even if the butter gets melty, put it back in the fridge to firm up and use it later.
How to soften butter easily?
During the winter, when my apartment is at a constant temperature of around 23°C / 73°F, I usually take the butter out of the refrigerator before going to bed. I put the whole pack on the counter and leave it overnight, so it’s ready for baking in the morning. On hot summer days, taking butter out is the first thing in the morning and it gets soft in an hour or so. But sometimes, like everyone, I forget.
The best way to quicken the softening process is by cutting the cold butter into smaller pieces and spreading them in a single layer on a plate. Small pieces will warm up and soften a lot quicker than the whole pack.
For an even faster method, you can warm up your oven to 30°C / 86°F, then turn it off and put the plate with the butter inside. Just make sure to check on it quite often so the butter warms up but doesn’t start to melt.
