Browned butter can go from nutty to burnt-tasting in the blink of an eye. To avoid that, you need to be able to discern its color as it cooks. Using a light-colored skillet, melt butter over medium heat. Bubbles will appear as water evaporates. Once bubbles subside, milk proteins will sink to the bottom while clarified butter, or ghee, floats above. Continue to cook, swirling the skillet. Stop when the solids are golden brown, or noisette—delicious in baked goods—or continue until dark brown, or noir, to mix with lemon juice as a dressing for seafood or vegetables.