Would you please pass the butter?

We made butter! When I saw this on Chasing Cheerios I knew we had to try it and it really works.
All you need is a jar, a marble, and some heavy cream.


Then here comes the hard part. Shake, Shake, Shake.
And keep shaking until you don't hear the marble anymore.


And yum, yum, yum. Pour off the buttermilk and save it if you need it. You now have fresh butter.