STEM Activity: You Butter Believe It!

Did you know you can make liquid cream transform into solid butter just by shaking it in a jar? Whether it ends up sizzling in a pan or melting on top of a stack of homemade pancakes, there’s a special science behind the creation of butter. If you’ve ever wondered how butter is made, you can recreate the process in just a few simple steps. Read on to learn how to make homemade butter with STEM!

Materials Needed

• 16-18 oz. jar with a lid (Consider reusing an empty jelly jar or mason jar!)
• Cold water
• Approximately 1 cup heavy whipping cream
• Large bowl
• Salt (optional)
• Strainer
• Sweet or savory mix-ins (optional)
• Timer

*Please Note: This activity will yield approximately 4 tablespoons, or half a stick, of butter.

Step-by-Step Instructions

1. Wash and sanitize your jar and lid before filling your clean jar halfway with heavy whipping cream. For salted butter, simply add a few shakes of salt to your jar.
    
2. Close the lid on your jar, ensuring that it is sealed tightly, and shake it vigorously for at least 15 minutes. Set a timer to keep track.
   
   After approximately 10 minutes, your jar will have whipped cream inside — keep shaking! If you get tired of shaking the jar, ask a friend or adult to take a turn!
    
3. Eventually, you will hear more of a thud or plop noise with some sloshing. This means your cream has separated into buttermilk and butter!
    
4. Open your jar and check its contents. Do you see solid, yellow butter sitting in white, milky liquid? If so, your butter is almost ready! If not, replace the lid and keep shaking it.
    
5. Gather a large bowl and strainer. Place the strainer in the bowl and pour the contents of your jar into the strainer.
    
6. Remove the strainer and set it aside so you can empty the buttermilk from the bowl. You can choose to save the buttermilk for another use or discard it.
   
   Buttermilk can be used to make pancakes, waffles, breads, fried chicken and soups, among other sweet and savory foods!
    
7. Add your butter back to the empty bowl and squeeze and press it together, like you’re making a snowball, to remove excess buttermilk. Empty any remaining buttermilk from the bowl.
    
8. Rinse your butter in the bowl with cold water, kneading it to remove any remaining liquids. Then, discard the water. Repeat this until all buttermilk has been rinsed from the butter and the water runs clear.
    
9. If you’d like to add sweet or savory flavors, like honey or roasted garlic, to your butter, allow it to soften slightly at room temperature in a bowl before using a spoon or hand mixer to stir in your desired mix-ins.
    
10. Form your homemade butter into the shape of your choice and store it in an airtight container in the refrigerator for up to 2 weeks.

Important Reminder: Homemade butter has a shorter shelf life compared to commercially processed butter. It is generally recommended to store homemade butter in a covered container in the refrigerator for up to two weeks, or in the freezer for up to six months. Homemade butter stored at room temperature should be used within a few days.

What Are We Discovering?

When butter is produced commercially, milk is spun quickly inside a machine to separate it into skimmed milk and cream. This process is called centrifugation. Next, the cream is collected and churned — shaken and stirred — until it separates into solid butter and liquid buttermilk. Then, the butter is removed, rinsed and blended until smooth. Finally, the butter is shaped, packaged and shipped in refrigerated trucks across the country!

Dairy products, like milk and butter, contain essential nutrients that strengthen our bones and support healthy immune systems. Thanks to National Inventors Hall of Fame^® Inductee Virginia Holsinger, healthier dairy products are available worldwide! Holsinger’s research on enzymes and digestion advanced the dairy industry and improved nutrition in American schools and international food donation programs. Holsinger’s innovations also created the foundation for Lactaid^® brand products, making milk digestible by those with lactose intolerance.

Explore More STEM This Year

Did you experiment with different flavors, create unique shapes or share your homemade butter with family and friends? We hope you continue to explore the exciting world of STEM, finding new ways to create and discover. Sign up to receive monthly emails filled with inspired approaches to everyday STEM.