Unsalted butter is melted over low heat and allowed to separate into butterfat and milk solids. The milk solids naturally sink to the bottom of the pan and, if left over gentle heat, will begin to brown. As the milk solids reach a toasty hazelnut color, the pan is removed from the heat. Beurre noisette may be used in its liquid state, or cooled to a solid form. It has a nutty flavour and is particularly included in the batters for madeleines and financiers.
If beurre noisette is not mixed after preparation but separated into the firm (protein) and liquid (fat) components, the latter is the type of clarified butter known as ghee in South Asia and samna in the Middle East countries.