Brown butter in baking: what it does and how to use it

Brown butter is one of those techniques that sounds more complicated than it is. You melt butter in a pan and keep going until the milk solids turn golden and the whole thing smells like hazelnuts and caramel. It takes about four minutes and it changes the flavour of almost anything you add it to. The banana loaf at Sparrow Windmill uses it, and it's the thing people most often ask about.

What is actually happening in the pan ¶

When butter melts and the water evaporates, the temperature of the remaining fat and milk solids rises above 100 degrees. At around 150 degrees, the Maillard reaction begins: the proteins and sugars in the milk solids react with each other and produce hundreds of new flavour compounds. The result is a nutty, caramel-like flavour that plain melted butter doesn't have.

The colour change is the indicator. Pale yellow means the water has evaporated but the Maillard reaction hasn't started. Golden brown means it's ready. Dark brown means you've gone too far and it will taste bitter. The transition from golden to dark happens quickly, so it's worth watching the pan rather than doing something else.

Where it works in baking ¶

Brown butter works well in anything where you'd normally use melted butter: banana bread, financiers, madeleines, blondies, and most loaf cakes. It also works in pastry cream and in some cookie recipes. It doesn't work as a substitute for creamed butter in recipes that rely on the aeration from beating butter and sugar together.

The banana loaf at Sparrow Windmill uses brown butter in place of plain melted butter and adds a small amount of miso paste, which amplifies the savoury-sweet quality. The first version of the recipe used plain butter and was fine. The brown butter version is noticeably better.

How to avoid burning it ¶

Use a light-coloured pan so you can see the colour of the milk solids clearly. Keep the heat at medium rather than high. Swirl the pan occasionally so the solids don't settle and burn on the bottom. As soon as it smells nutty and looks golden, take it off the heat and pour it into a cold bowl to stop the cooking.

If you're making a large batch for a recipe, it's worth browning slightly more than you need, because some will stick to the pan and some will be lost in the transfer.

The banana loaf is on the counter most mornings. If you want to know more about the recipe, Helen is usually happy to talk through it.