Add some heavy whipping cream to a stand mixer with the whisk attachment or a food processor and mix or process on high speed until the buttermilk separates from the milk fat, about 5 minutes.
Strain the buttermilk away from the butter. Keep the buttermilk for a recipe of your choice.
Drain the butter through a chinois or cheesecloth to drain off all buttermilk. If using a chinois press down using a spatula but if using cheesecloth wrap up the butter and twist it to get out as much buttermilk as possible.
Rinse the butter under cold water to remove any excess buttermilk.
Cover and store or season with salt and serve.
Chef Notes:Make-Ahead: You can make this up to 3 days ahead of time.How to Store: Cover and keep in the refrigerator for up to 3 weeks. Cover and freeze for up to 3 months.Butter will last up to 3 weeks if kept cold, covered, and completely free of buttermilk.If there is still buttermilk in the butter, it can spoil in under 10 days.You can also make butter by vigorously shaking the whipped cream in a mason jar until the buttermilk separates from the milk fats.