Start by measuring out your heavy cream. If you’re using mesophilic culture, sprinkle it over the cream and let it sit for about 5 minutes.
Using a whisk or electric mixer, begin whipping the cream. Start on a low speed, gradually increasing the speed until the cream thickens.
Continue whipping past the soft peaks stage until the butter separates from the buttermilk, about 10 to 15 minutes.
Place a fine mesh strainer over a bowl and pour the contents of your mixing bowl into it, allowing the buttermilk to drain out.
Rinse the butter under cold water and knead gently to remove any remaining buttermilk.
If you prefer salted butter, mix in your fine sea salt to taste.
Transfer your homemade butter to a storage container, shape it if desired, and store in the refrigerator.
