Homemade Butter in a Mason Jar Science Experiment

With just heavy cream and a jar with a lid, your kids can make homemade butter in a mason jar after having lots of fun and a full-body workout shaking the jar.


If your kids are anything like mine, they love to get their hands “dirty” helping mom in the kitchen. Therefore, I am constantly looking for easy things they can do without making a huge mess while I cook.

That’s why this homemade butter in a mason jar activity is such a great way for kids to be part of the food preparation process. Everything is contained in the jar so you don’t have to worry about spillage or cleaning up food off the walls.

Plus, making butter is also a fun and simple science experiment! Even my preschooler can do this – it’s that easy.

How to Make Homemade Butter in a Mason Jar

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  • Mason jar (you can use baby food jars too for little hands)
  • Heavy cream
  • Optional: salt, honey, herbs, cinnamon, etc. (to make gourmet butter)


1. Fill your mason jar about half-way with heavy cream. Seal the mason jar with the lid and screw-ring.

2. Start shaking the jar and check the inside after 2 minutes. You will find that there is whipped cream in the jar. Give it a taste!

Homemade Butter in Mason Jar Whipped Cream

3. Screw the lid back on and continue shaking until you hear liquid sloshing and see a lump has formed inside. Now you have butter and buttermilk! This will take about 7-10 minutes, depending on how much heavy cream you poured in, and how vigorously and continuously you shake the jar.

Buttermilk and Homemade Butter in Mason Jar

4. Continue shaking the jar for an additional 30-60 seconds.

5. Open the jar and carefully pour out the buttermilk. You can save it for baking later. You may want to use a spoon to make sure the butter doesn’t slide out.

Homemade Butter in Mason Jar Separate Buttermilk

6. Remove the butter from the jar and place it in a bowl. 

7. Rinse the butter with cold water. You will want to use your hands to squish the butter and get all the buttermilk out. This will help prevent your butter from going rancid quickly.

Optional: Add and mix some salt, honey, herbs, etc. if you want to add some flavor to your butter. 

Serve the butter on a plate. Enjoy!

Homemade Butter in Mason Jar Butter on Plate

My kids certainly enjoyed making their own butter. After all, they got to shake a jar as hard as they wanted and whichever way they wanted. They were amazed how heavy cream turned into whipped cream, then turned into butter and buttermilk. 

When the butter is all done and ready to eat, they asked, “Really? We can eat this?”

And let me tell you, homemade butter melts in your mouth. It’s so much lighter and fluffier than store-bought butter. Just spread it on some fresh bread and taste the goodness!

Science Behind Making Butter

To understand how heavy cream turns into butter and buttermilk, we first need to understand how heavy cream is made.

When whole milk is left out uncovered in the fridge, fat molecules in the milk float to the top, forming the layer of heavy cream. If you have whole milk, maybe you can start the experiment by making your own heavy cream first! 

When we shake the heavy cream in the mason jar, the agitation causes the fat molecules to clump together. At the same time, the water molecules are squeezed out of the solid mass and become buttermilk.

The whole process is reversible. If you want to experiment further, you can melt the homemade butter and mix it with the buttermilk. But I am not sure if you want to do this when the butter is so delicious!

Frequently Asked Questions

Can I turn whole milk into butter?

Unfortunately, whole milk does not have enough fat content to turn into butter. The only way to make butter from milk is to first make heavy cream by letting your milk sit out in the fridge overnight.

Can I turn half-and-half into butter?

Similar to the answer above with whole milk, half-and-half still does not have enough fat content to make butter. You need to use heavy cream.

What’s the easiest way to make homemade butter?

If shaking a mason jar and getting an arm workout is not your thing, then there are a few options. Remember, the key is to agitate the fat molecules out of the heavy cream, so you can use any device that can shake or stir the heavy cream until the fat molecules lump together.

  1. You can use a stand mixer and mix the heavy cream on high speed until the butter fat separating from buttermilk.
  2. Similar to the stand mixer, you can use a hand mixer.
  3. Still want an arm workout? Use a whisk and beat the heavy cream until you see a solid mass has formed.
  4. Use this Chef’n Buttercup Butter Maker instead of a mason jar. It has a built-in sieve that strains off the buttermilk and you can enjoy homemade butter within 3 minutes!

How long can I store homemade butter?

Since homemade butter has no preservatives (one of the beauties of making your own butter!), it won’t last long at room temperature. You can store it in the fridge for about 5-7 days before it spoils.

Honestly, homemade butter is so good that it probably won’t last that long before it’s gone!

Final Thoughts on Making Homemade Butter with Kids

Things always taste better when you make it yourself, and I find this to be very true with kids. They can make the most disgusting food creations and still enjoy them because they had a hand in making them.

The good thing about making homemade butter is that it’s so easy that you can’t mess it up! 

My kids certainly loved the homemade butter on freshly-baked bread, and I used the rest to bake a loaf of banana bread. Since it’s so easy to make, I figured I will just whip up a fresh batch next time we want it.

Bon appetite!



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2 thoughts on “Homemade Butter in a Mason Jar Science Experiment”

  1. What happens if you shake it too long and the whole thing turns to a solid? There is no buttermilk to drain. Is it still usable as a butter?

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