Pour 2-4 cups of heavy whipping cream into a mixing bowl.
Use the whisk attachment and beat on low-med and gradually increasing the speed to med-high as it thickens (if you start out on high the thin cream will spray out of the machine and make a mess).
The cream will go from looking like cream to whipped cream after a few minutes. Keep mixing!
After another couple of minutes the cream will look yellow and the fat will begin to separate from the buttermilk. Once you see what looks like crumbles of butter sloshing around milk turn the mixer off.
Pour contents of bowl into a strainer. Place a bowl underneath to catch the buttermilk if you'd like.
Remove bowl of buttermilk then run the strainer under COLD water. Press butter with a rubber spatula to shape and rinse it. You want to rinse ALL of the buttermilk off of the butter. I usually rinse and press 2x.
Mold the butter into a ball shape using your hands. You have just made unsalted butter.
You can sprinkle the butter with ¼ teaspoon of salt and press it into the butter using a spoon before slathering it over slices of our no knead crusty bread!
Video
Notes
Butter can be stored at room temperature or refrigerated.