By Jeremy Round
The fat content of the original cream dictates the luxuriousness of this thick, slightly tart cream, used all over France as we would use double cream. Some cooks add a much greater proportion of souring agent than in the recipe below – up to one part in every two of the ‘ordinary’ cream. Some use sour cream instead of buttermilk.
Heat together over a gentle flame until the mixture feels still slightly cool to a dipped finger. Leave overnight in a vacuum flask or covered in a warm place – such as an airing cupboard. Stir, then keep in a covered bowl in the fridge. It will ripen and thicken over a few days.