Add cold heavy cream to a mixing bowl (make sure it's real cream without stabilizers like carrageenan, or it won't separate properly)
Beat on medium-high until it turns into whipped cream — then keep going
Once it starts forming yellow clumps, drape a towel over the mixer so it doesn't spray everywhere
Keep mixing until the solids fully pull away from the liquid
Pour off the buttermilk and set it aside for pancakes or baking
Rinse the butter in ice water and gently squeeze out any leftover liquid so it stays fresher longer
Add a pinch of salt if you want, then pack it into a crock or shape it however you like
