Did you know you could turn milk into plastic? I had no idea!
I did know that you can turn cream into butter, which is just what I was planning on doing with one of my Kindergarten classes back when I taught in the classroom. We love easy science experiments!
There I was, armed with gallons of cream (which, as it turns out, was way more cream than needed), when one of my lovely colleagues said, “Oh! Are you making plastic?”
I looked at her as if she were insane and said, “No… this is cream.”
She then smiled and said, “Oh, I thought it was milk,” and started to walk away.
As if you could walk away after a sentence like that! I quickly chased after her and got all the details on how to turn milk into plastic. Turns out—she’s not insane! You really can! Best of all, you only need to add one other ingredient!!
Let me show you how!
Free Printable Science Experiment Instructions
Good news, friends, you can turn milk into plastic, and I have worked out all the kinks! I have done this science experiment more than a few times (it’s that awesome), and I have all the details just for you. This is such a great STEM activity for kids!
Before we get into it, you’ll also want to grab your FREE Printable Instructions. Little ones will love being able to follow along, helping with each step as they take part in this experiment:
How to Turn Milk into Plastic
You can turn milk into “plastic” in minutes with only milk, vinegar, and a few kitchen supplies—and it is fantastic.
Materials
- 1 cup whole milk
- 4 tbsp vinegar
- microwavable bowl or a saucepan
- mixing bowl
- strainer
- spoon
- paper towel
- cookie cutters
- food coloring, optional
Directions
Step 1: Heat the Milk
First, take 1 cup of milk and warm it in the microwave for about 1.5 minutes, or slowly heat it in a pot on the stove (you want the milk hot but not boiling).
Step 2: Add Vinegar and Stir
Next, stir in 4 tablespoons of vinegar. The milk will start to clump as the acid in the vinegar breaks down the protein in the milk. Stir for about 1 minute.
Step 3: Strain the Liquid
Strain the milk through a strainer. All the clumps will stay in the strainer, so really push on them to get all the liquid out.
Step 4: Shape and Color
Finally, transfer it to some paper towels and continue to press all the liquid out of the plastic milk. You can add a few drops of food coloring if you’d like, or leave it white—we’ve done both! Then, shape the “plastic” by pressing it into a cookie cutter.
I flipped our cookie cutters over so you could get a better look at how it compresses, as shown in the photo below (we opted to keep these little stars white).
Step 5: Let Dry and Display!
Set them aside to dry for a good long while—it could take a couple of nights, or you can pop them in the fridge to help them harden a bit faster—then they’re ready! Once they’re hardened, they are ready to be hung up in a window, on a door, or used to decorate a Christmas tree!
My kids just loved this science experiment; I hope yours will, too!
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So this is the takeaway lesson here, friends:
If someone says something that doesn’t make sense, chase them down the school hallway and ask questions! You might discover the coolest science experiment of all time.
If your children enjoy learning and experimenting in the kitchen, they’ll love my Edible Science Family Unit Study! It is full of delicious, hands-on activities—from learning about states of matter while making popsicles to discovering how harvested cacao pods become chocolate while making some delightful chocolate-dipped cookies, and so much more.
Check out Edible Science in the How Wee Learn shop!
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Thank you so much for reading, my friend!
xo
Sarah
