Beurre noisette, literally hazelnut butter, is often used in French cooking and baking, and it is therefore good to know how to make it. The hazelnut doesn’t only refer to the color, but also to the nutty smell and taste of butter that has been treated this way. It can be used as a sauce or spread by itself, or added to more complex preparations. Beurre noisette is prepared in a similar way to clarified butter, i.e. by heating it — the main difference is that it is cooked for a longer time.
Butter consists of about 80% butter fat, 1% proteins, and 19% water. In clarified butter the proteins and water are removed to make the butter more suitable for frying. It is the proteins that give beurre noisette its color, smell, and flavor. The preparation is not difficult but it is easy to mess it up, because if you heat them too quickly the proteins will burn instead of brown. This means that you have to control the heat carefully. If you follow the steps below, nothing can go wrong. It is easiest to do this with a thick-bottomed saucepan with good heat distribution, but if you stir enough you should even be able to make this with a saucepan that has poor heat distribution.
Use unsalted butter. Cut it into cubes of equal size to ensure even melting and place those cubes in a saucepan.
Melt the butter over medium heat, stirring. If the heat is too high or you don’t stir enough, the butter will burn.
First the butter will melt. Keep stirring.
Then the water in the butter will start to boil, and proteins will float to the top. Keep stirring.
After a while most of the water will be gone, and the proteins will sink to the bottom. Keep stirring.
As soon as the butter starts to change color, pay close attention as it will go quickly from brown to black if you are not careful. Keep stirring, and as soon as the butter is brown, take the saucepan off the heat…
…and pour the beurre noisette into a bowl. If you only turn off the heat but keep the butter in the hot pan, it could still burn.
You can use the beurre noisette right away as a sauce, or allow it to cool.
The browned proteins will sink to the bottom…
…so stir the beurre noisette regularly as it cools, to keep the proteins evenly distributed. Once cooled down, it can be stored in the refrigerator for quite some time. Take care when reheating, because it will burn almost straight away if heated over high heat.