• Put butter into a saucepan and turn the heat up to medium.
• Attach your candy thermometer if you’ve got one, and watch the temperature.
• After a few minutes the butter will start to boil. If you’ve got a candy thermometer, the liquid will stay at 100ºC (212ºF) until the water cooks off.
• Once the mixture stops boiling, turn the heat down to medium-low. Keep an eye on the thermometer. The temperature will start creeping up. Stir gently, periodically with your spatula to mix the milk solids around. When the oil reaches 140ºC (284ºF), take the pan off the heat and pour into a container. If using a glass container, make sure it is very hot to avoid cracking.
• If you don’t have a thermometer, you’ll see the mixture start to bubble rapidly and foam a bit. It may be a little difficult to see the milk solids at the bottom but you can take a spoon to scoop them up and inspect them. When they’re a golden brown, take it off the heat.
• You can store this butter in a cool, dry place for about a month (if it lasts that long).

To whip:

(I don’t like to wait to whip it because it takes forever to solidify, so here’s my trick)

• Pour the browned butter into a bowl (preferably metal, so it gets cold fast). Pop the bowl into the freezer for 10 minutes. Stir it up and let it sit for another few minutes, until it’s about 50% solid. If it gets too hard, put the bowl over some hot water until a little bit of it is melted. It should be soft but opaque.
• Then whip it with a hand mixer until it’s light in color and fluffy.