Brown butter is just unsalted butter that has been melted and gently cooked to bring out a toasty, nutty flavor. It's delicious in endless sweet and savory recipes!
Add the butter to a light colored pan and melt over medium heat. Once melted stir frequently and watch closely for the formation of brown specs on the bottom of the pan.
First the butter will get thick and foamy. Then it will start to bubble rapidly. Don't stop stirring the butter. After a few minutes, the butter will start to turn a golden brown color and you'll start to see those brown specs on the bottom of the pan. It will smell intensely buttery, nutty, and rich.
Once you see the brown specs, remove from the heat and immediately pour into a separate heat-proof bowl to stop the cooking process. Let the butter cool to room temperature.
All the browned specs will sink to the bottom of the bowl. So as the butter cools and starts to solidify, it's important to stir it often so that the browed bits (aka where all the flavor is) gets evenly incorporated through all the butter! Once the brown butter is fully cooled to room temperature and stirred well, you can transfer it to the fridge to harden.
Note: For every ½ cup (1 stick or 113g), you'll lose about 1 tablespoon (14g) to evaporation while cooking. So you can either add in 1 tablespoon before browning, or if you're browning big batches, just make up the weight difference in your recipe with regular unsalted butter if needed.
Notes
Make-Ahead & Freezing Instructions: You can prepare brown butter ahead of time. Since butter is solid at room temperature, the browned butter will solidify. Cover and store in the refrigerator for up to 5 days or in the freezer for up to 3 months. Use a kitchen scale to weight out the correct amount of brown butter for recipes. 1 cup of butter equals 113 grams.