Plastic Milk Science Experiment

With 2 simple ingredients you have in your kitchen you can quickly and easily make your own plastic! Kids are going to be super impressed with this fun, hands on science experiment for kids. plastic-milk-science-project

I love doing science experiments that impress kids!

Not only are they eager to learn, but it stretches their little minds.

Today’s science experiment is going to really impress your kids!

Plastic Milk Science Experiment

To start out with you are going to heat up 1 cup of milk to almost boiling in a saucepan or by microwaving for 2 minutes.

Hint: I suggest using non-homogenized milk if possible for better clumpingheat milk to just before boiling
Take off from heat and add 4 teaspoon white vinegar and stir for 1 minute. You will see the milk separate and clumps form.
drain out liquid in a strainer
Now pour into a strainer to get rid of the extra liquid.
you'll be left with lumps

This is what you are left with.

add some food coloring drops to color your plastic

If you’d like to color your plastic, just put a drop or two of food coloring in several small bowels and pour the milk in them just after you’ve added the vinegar; stir.

pat dry with paper towel

Spoon out your clumps from the strainer and pat dry with a paper towel. The more liquid you pat out the stronger plastic you will make.


The mixture can be formed into a ball and pressed flat. I suggest using a cookie small cookie cutter shape your mixture. Press down until it is smooth.

Allow to harden for a couple days.
 making plastic out of milk

Wondering about the science?

You made a substance called CASEIN which occurs when the protein in the milk meets the acid in the vinegar. The casein in milk does not mix with the acid and so it forms blobs.

Tip: This is a fun and interesting science activity for kids, but I would not recommend keeping it long term as it may sweat.

Science Experiments for Kids

Beth Gorden
Beth Gorden

Beth Gorden is a homeschooling mother of six who strives to enjoy every moment with her kids through hands-on learning, crafts, new experiences, and lots of playing together. Beth is also the creator and author of 123 Homeschool 4 Me where she shares 1000+ free printables, creative homeschool lessons, crafts, and other fun ideas to help preschool and homeschooling families have fun while learning and exploring together.