Shake Your Own Butter

Big question: How does shaking turn cream into butter?

Shake cream in a jar until it thumps, then open it up to find homemade butter and buttermilk inside.

What you need

• 1 cup heavy cream (the thick cream sold for whipping)
• A sturdy plastic jar with a tight lid that holds about 2 cups (not glass, in case it slips)
• A pinch of salt
• A bowl of cold water
• Bread or crackers

What to do

1. Fill the jarWash your hands first and check every ingredient with your grown-up. Pour the cream into the jar so it is about half full. Your grown-up checks that the lid is tight.
2. Shake, shake, shakeShake the jar up and down, taking turns when your arms get tired. After a few minutes the cream thickens into whipped cream and goes quiet. Keep going.
3. Listen for the thumpSuddenly you hear a thump. A yellow lump is sloshing in watery liquid. The lump is butter, and the liquid is buttermilk.
4. Rinse the butterPour off the buttermilk. Squeeze the butter in the cold water with clean hands to wash out the last drops, so your butter stays fresh longer. Then mix in the salt.
5. Taste itSpread your butter on bread or a cracker. You made it with nothing but cream and muscles.

What is happening?

Cream is tiny droplets of fat floating in a watery liquid, and each droplet has a thin skin. Shaking smashes the droplets together until the skins break. The bare fat sticks together, first trapping air as whipped cream, then clumping into bigger lumps until it all joins into butter. The watery part left over is buttermilk, a thin, mild kind that is different from the tangy buttermilk sold in stores.

Use a plastic jar, not glass, and shake over a table in case it slips. Keep the cream in the fridge until you start. Keep your butter and buttermilk in the fridge and use them within a few days.

Try it

• 
  Little Helpers

  Vanilla Blueberry Muffins

• 
  Little Helpers

  Strawberry Milk

Check yourself