When I was a kid, we had one cow, hence above title. The cow produced insanely rich milk--even after running the milk through a separator (hand-cranked), a gob of cream would still settle at the top of the milk bottles. So anyway, my mother would make butter by putting the cream in a pint mason jar and we'd pass it back and forth, shaking it for maybe 30 minutes. Result was wonderfully rich but just a little tangy--enough to make it interesting. No way of course one could duplicate the circumstances, but on the other hand if you can find really first rate unpasteurized cream, making it yourself is not a big deal. As to what you do while shaking cream for 30 minutes, dunno, maybe watch a Cubs game.