Grab a canning jar and whipping cream

Pour cream into jar and seal with lid.

Shake vigorously up and down, in approximately 10 minutes. The cream will get foamy and then turn to what resembles mayonnaise. You are almost there.

Now shake it hard. It will change fast. The mayonnaise consistancy will all of a sudden separate and you will have milk, and butter.

Drain jar into strainer

Form butter into log using plastic wrap and allow excess milk to drip out. Tighten and refrigerate.