Homemade cultured butter ingredients: Heavy cream (35% fat content): 1 L, about 1 kg, Buttermilk: 60 g, 1/4 cup, Ferment for 1-2 days at the room temperature. After completely chilled in the fridge. Beat the cream in a mixer at the highest speed. 2-3 minutes later, butter is completely separated from the cream. The liquid left is buttermilk. Wash the butter with cold water. Shape it and store in the fridge.