How to Brown Butter (Beurre Noisette)

Browning butter means cooking it past the melted stage until its water boils off and its milk solids toast to a nutty amber, usually 5 to 8 minutes over medium heat. The French call it beurre noisette, "hazelnut butter," after its colour and aroma.

What's actually happening in the pan

Butter is roughly 80 to 82 percent fat, 15 to 17 percent water and 1 to 2 percent milk solids (proteins like casein and whey, plus lactose). Each part plays a role.

Stage 1, melting. The butter liquefies around 32 to 35 °C / 90 to 95 °F.

Stage 2, boiling. The water heats to 100 °C / 212 °F and boils off. This is the loud, spitting, foamy stage. As long as water is present, the butter can't get much hotter than 100 °C, so nothing browns yet.

Stage 3, browning. Once the water is gone, the foam quiets and the temperature climbs quickly. The milk proteins and lactose sink, then undergo the Maillard reaction and some caramelization, somewhere around 120 to 150 °C / 250 to 300 °F. That creates hundreds of new aroma compounds: toasty, nutty, butterscotch-like.

Stage 4, burning. Push past about 175 °C / 350 °F and the solids go from brown to black and taste bitter. The gap between stage 3 and stage 4 can be as short as 30 seconds, which is why this technique is mostly about paying attention.

Choosing the right pan

Use a light-coloured pan, such as stainless steel or enamelled cast iron with a pale interior. In a dark nonstick or black cast iron pan, you can't see the solids change colour, and you'll find out by smell, usually too late.

A pan with a heavy base heats evenly and prevents hot spots that scorch the solids in one corner while the rest is still pale. Size matters too: 115 to 225 g (1/2 to 1 cup) of butter is best in a small saucepan or 20 cm (8 in) skillet, so the solids pool deep enough to see.

Steps

1. Cut the butter into even pieces so it melts at the same rate.
2. Put it in a light-coloured pan over medium heat.
3. Let it melt, then keep swirling or stirring as it bubbles and spits.
4. Watch for the foam to quiet down as the water cooks off.
5. Scrape the bottom often once you see tan specks forming.
6. Pull the pan off the heat when the specks are hazelnut brown and it smells nutty.
7. Pour it immediately into a heatproof bowl, scraping in all the browned bits.
8. Use it warm, or chill it until solid for baking that calls for soft brown butter.

How to tell when it's done

Use three senses together:

• Sound. The crackling and spitting fade to a gentle fizz. That's your cue that the water is nearly gone and browning is about to start.
• Sight. A fine foam sits on top; push it aside with a spatula to see the bottom. You want golden-brown to hazelnut-brown specks, and the fat itself turns a clear amber.
• Smell. It goes from "melted butter" to toasted nuts and caramel. Acrid or smoky means you've gone too far.

The pan keeps cooking the butter after you take it off the heat. Pour it out when it's one shade lighter than you want, the same idea as carryover cooking.

Chef Fizz says: The brown specks are the flavour. Don't strain them out unless the recipe tells you to. Scrape every last bit into the bowl.

Using brown butter in baking

Brown butter has no water left, so swapping it 1:1 by weight for regular butter changes a recipe. Two simple fixes:

• Weigh before browning. Start with about 20 percent more butter than the recipe calls for, or add 1 to 2 tablespoons of water or milk back to the dough per 225 g (1 cup) of butter.
• Match the state. If the recipe needs creamed butter, chill the brown butter until it's solid but soft, about 18 °C / 65 °F, before you cream it with sugar. Liquid brown butter can't hold air.

It's excellent in chocolate chip cookies, blondies, financiers, banana bread and pound cake. For savoury food, spoon it over pasta with sage, fish, roasted squash or gnocchi.

Common mistakes and fixes

Heat too high. On high heat, the outside solids burn before the water is gone. Medium is fast enough.

Walking away. The last minute is when everything happens. Stay at the stove.

Leaving it in the pan. Residual heat in a heavy pan can take the butter from brown to burnt in under a minute. Always pour it out.

Using a dark pan. If you have no choice, spoon a little onto a white plate every 20 seconds to check the colour.

Too little butter. Under about 55 g (4 tablespoons), the solids are so few and so shallow that they burn almost instantly. Brown at least 115 g and save the extra.

Bitter results. Black specks and a sharp, smoky smell mean the solids burned. Straining helps a little, but for anything delicate, start over.