Add the cream to the bowl of a stand mixer. Turn to medium high.
Continue mixing until the butter separates from the buttermilk, about 3-10 minutes.
Drain the buttermilk and refrigerate for later. Use the buttermilk for buttermilk biscuits or pancakes.
Wash the butter by squeezing and kneading it under running water to release the remaining buttermilk. Keep washing the butter until the water is clear, about 5 minutes.
Optional: Add salt to taste. Begin by adding 1 teaspoon of kosher salt to the butter and mix well. Taste and add more if desired.
Store the butter in a sealed container in the refrigerator for 2-3 weeks. For longer storage, freeze for up to three months.
This recipe makes about 1 pound of butter and roughly 2 cups of buttermilk.