- 4 cups heavy cream
- ½ cup plain yogurt or buttermilk
- fine sea salt, or to taste
- Combine cream and yogurt/buttermilk. Cover with a clean kitchen towel and let mixture sit in a warm area of your kitchen for 18 to 36 hours; it should thicken and taste rich, sour, and tangy.
- Seal tightly with plastic wrap and refrigerate until it reaches 60 degrees, 1 to 2 hours.
- Line a fine-mesh sieve with a double layer of cheesecloth and place it over a large bowl.
- Take a kitchen aid or a food processor and add the thickened butter mixture and process on high until the yellow curds begin to separate from the buttermilk, 2 to 3 minutes. Look out it will happen very fast and will slosh everywhere.
- Place it in a mesh sieve and let sit for 1 to 2 minutes, allowing buttermilk to drip through. Gather the ends of the cheesecloth up and around the butter and shape it into a ball. Squeeze out as much buttermilk as possible. You will be left with a butterball.
- Save buttermilk.
- Place the butter in a metal bowl and “wash” the butter, folding it over itself and pressing down to extract the extra buttermilk. Drain off the milky liquid and discard it; repeat this process until the liquid is clear, 4 to 6 times. The butter will start to harden.
- Pat the butter lightly on a kitchen towel to remove excess moisture; this will help extend its storage life. Kneed in salt to taste.
- Lay out a sheet of parchment paper and twist the sides to make a “butter log” The butter will last about a month in the refrigerator.