Black butter (Le nièr beurre) is not butter at all, but a preserve made from apples for spreading on bread. Its production starts on an autumn or winter evening - known as a black butter night. A large number of neighbours and family members would join the farmer's wife the day before, peeling and slicing a large quantity of apples.
They were destined for la piêle, a huge brass preserving pan with a capacity of some ten gallons. It was set up on a tripod and a fire lit beneath. The recipe calls for a gallon of cider to be poured into the pan for every 70lb of apples, plus sugar, lemon and spices to give the mixture its distinctive flavour. Not surprisingly every farmer's wife would have her own individual recipe. The cider is kept simmering all day and the apples are added in the evening. From then on two or three men are employed non-stop stirring the mixture with un moueux, a wooden rake.
It is an occasion for a joyful get-together of family, friends and neighbours, lasting until dawn, when each helper goes home with a share of the black butter, the remainder being left for the use of the farmer's wife or for sale.