With its natural sweetness, one taste of homemade butter may have you swearing off the store-bought sticks. It also freezes well, so make a few batches at once. Reserve the buttermilk in Step 4 for other uses, like these Old-Fashioned Buttermilk Rolls.
- 4 cups high-quality heavy whipping cream
- ½ cup cultured whole buttermilk
- ½ teaspoon kosher salt (optional)
- In a medium cast-iron Dutch oven, heat cream over medium-low heat, stirring occasionally, until an instant-read thermometer registers 70°, 4 to 7 minutes. Remove from heat; stir in buttermilk. Cover Dutch oven loosely with plastic wrap. Let stand at room temperature at least overnight or up to 24 hours.
- Refrigerate cream mixture for 1 hour.
- Uncover cream mixture, and stir. (Mixture should be thick.) Pour into a the bowl of a stand mixer fitted with the whisk attachment. Drop a large kitchen towel over mixer to catch splatters. Beat at medium-high speed until cream begins to separate, about 5 minutes. Reduce mixer speed to medium-low; continue beating until butter solids and buttermilk have completely separated, about 5 minutes. (Solids will be yellow in color and mostly clump inside whisk.)
- Place a fine-mesh sieve lined with two layers of ultra fine cheese cloth over a large bowl. Pour in butter mixture; gather cheesecloth around butter solids, and squeeze to release liquid. Reserve buttermilk for another use.
- Fill a large bowl with ice water. Place butter solids in another large bowl; add about ½ cup ice water to butter. Using a silicone spatula, knead butter until water is cloudy. Drain, and repeat until water runs clear, 6 to 8 washings. (Use hands to knead toward end of process, if necessary.) Knead salt directly into butter, if desired. Pack butter into an airtight container. Cover and refrigerate until firm before using, 1 to 2 hours. To store, wrap tightly in plastic wrap and refrigerate for up to two weeks or freeze in a heavy-duty resealable plastic bag for up to 3 months.