Pour your heavy cream into a Kitchenaid mixer (or any other mixer with a whipping beater), set it on medium high, when it becomes whipped cream you are almost there! Keep mixing until it begins to separate into clumps of butter and separate from the buttermilk. Once it does that, pour off the liquid into a jar and keep for dressings and recipes. Now I like to add a pinch on salt, but you can leave it unsalted. Work as much liquid out of the butter by pressing it with a wooden spoon against the sides of the bowl, draining the liquid as it drains out of the butter. Try to get as much liquid out, as it will keep longer without going rancid if you do. It's not going to save money to do this...,but it's very interesting and delicious!
The amount shown in the photo represents using 1 pint of cream. You will get twice that amount using the whole quart of cream.