Success!  Butter has been made.

It turns out that shaking a marble-free jar of cream makes butter pretty much just as effectively as shaking a jar of cream with a marble in it, except there’s no broken glass this way.  It also turns out that cream labeled “heavy whipping cream” makes butter faster.

The butter is delicious.

Ingredients:

1 pint or half pint of cream (not ultra-pasteurized; it won’t work)

1 large jar

0 marbles

many vigorous shakes

Directions: put cream in jar.  Do not put marbles in jar.  Close and shake jar a lot.  Peek in jar frequently.  At whipped cream stage, taste and purr.  When tiny bits of butter start appearing, get excited.  Keep shaking until you have a large clump of butter and the liquid has separated.  Eat.  Purr again.