Shake it Till You Make it: Homemade Butter & Emulsions

KITCHEN SCIENCE: June 5, 2025

CONCEPTS

Emulsions and physical changes in food

Mechanical separation of fat and liquid

Historical methods of food preparation and preservation

TOOLS & SUPPLIES

1 small jar with a lid

1/4 cup heavy whipping cream

Salt (optional)

Butter in a Jar: Shake, Separate and Spread

In the first week of our June 2025 series, we dive into the science of emulsions. So what is an emulsion? An emulsion is a mixture where fat and liquid are combined into one smooth substance. Heavy cream is an emulsion, but when we shake it vigorously, the fat molecules separate from the liquid. This is how butter was made for generations before modern machines - just by shaking or churning!

Butter has long been a part of Southern and rural food traditions, often made fresh at home. During the Great Migration, families brought these skills and memories with them, even as they adjusted to city life and store-bought alternatives. In this experiment, we make butter the old-fashioned way and taste the results of science in action!

METHOD

Step 1: Pour & Seal

Pour 1/4 cup of heavy whipping cream into a small jar.

Seal the lid tightly so there are no leaks. You can tip the jar to test this.

Step 2: Shake It!

Shake the jar vigorously for 5-7 minutes.

At first, it will turn into whipped cream!

Keep shaking until you hear a slosh. The butter and buttermilk have separated!

Step 3: Strain & Press

Carefully open the jar and pour off the buttermilk. You can save this for another recipe.

Use a spoon or clean hands to press the butter against the side of the jar to remove excess liquid.

Step 4: Taste & Observe

Rinse the butter under cold water if you will be storing it.

Add a pinch of salt, spread it on bread or a cracker, and taste!

Record your observations.

DISCUSSION QUESTIONS

  1. What physical change happed to the cream?

    a. What did the cream look like before? During? After?

  2. Why do you think early families made butter this way?

  3. How does this tie into food traditions passed down during the great migration?