1 cup heavy (whipping) cream
1 pint or 500 ml canning jar with a tight fitting lid
Pour the cream into the canning jar.
Secure lid and shake vigorously.
The butter will begin to appear (depending on how hard your shake, it can take up to 10 to 15 minutes) and the buttermilk (a cloudy liquid) will separate from the solid lump of butter.
Carefully pour out the buttermilk and add a small amount of cold water to the jar. Shake and pour out the liquid. Repeat until the water is clear.
Set the cheesecloth over a container (I used a medium sized Tupperware container with lid) to drain any excess water that may still be in the clump of butter and place in refrigerator.
When the butter begins to solidify, salt to taste and serve.