This recipe was given to me by Gayle Thorpe on Saturday, July 23, 2005, along with a pint sample. This is the most delicious butter I have ever had in my life. It is made with crème fraîche.
Skim the milk of the cream on the top. For every cup of cream, add 1/4 cup of already cultured crème fraîche or commercial cultured buttermilk. Leave in a clean, covered glass jar for 12 to 24 hours at room temperature. In hot weather, 12 to 18 hours is sufficient. The cream will thicken. Refrigerate after its culture time is over. It will thicken like sour cream after refrigeration. You can use it like sour cream.
Take chilled crème fraîche; beat in food processor or mixer until it separates. Pour off the resulting cultured buttermilk and use in baking or to make more crème fraîche (refrigerate). Run the butter under cold running water (or place in ice water in bowl) while you work out the remaining buttermilk with your hands. Add Redmond sea salt to taste. This butter keeps longer than fresh cream butter. Refrigerate.