Make Your Own Plastic Out of Vinegar and Milk

Make your own plastic

Did you know that you can make your own plastic out of milk and vinegar??

For his 10th birthday, Aidan received the book Sneaky Uses for Everyday Things (affiliate link) from one of his friends.  It’s a pretty awesome book. The book contains 42 different inventions to make out of household materials such as a homemade battery, an electronic greeting card, and a makeshift telescope.  Aidan was really intrigued by the page on how to make plastic out of milk and vinegar.  I stalled for several days on this one because it sounded messy and smelly, but we finally did the project and wow!  It was easy to do and SO much fun!

To make plastic, you will need:

  • 1 cup of milk
  • 1 Tablespoon of vinegar
  • A small pan
  • A spoon
  • A strainer
  • Paper towels
  • Food coloring (optional)

First, put one cup of milk in a pan and heat it until warm.  It doesn’t need to boil – just be warm.

Make your own plastic

When the milk is warm, stir in 1 T of vinegar.  The vinegar will cause the milk to quickly separate into curds and whey.  The acid in the vinegar causes the protein strands in the milk to coagulate.  The curds are casein, which is used in the production of glue and some plastics.  Who knew?

Make your own plastic out of milk and vinegar

Pour the contents of the pan into a strainer.  Use a spoon to squish out the extra liquid.

Make your own plastic

 Knead your plastic with your hands and use a paper towel to dry off any excess moisture.

Make your own plastic

Then mold your plastic into whatever shape you want!  It’s a little tricky to mold because it has a texture sort of like ricotta cheese (which is probably what it is?).  We flattened it out and used a measuring spoon to cut out circle shapes for key chains.

Make your own plastic

We also made a second batch and added a few drops of blue food coloring to the milk before heating.

Make your own plastic

Let your creations dry for 48 hours or more.  I had my doubts about this stuff becoming anything that resembled plastic, but it worked!!!  We found that smaller, thinner shapes dried better and faster.  The blue color dried darker than it looked when it was wet.

Make your own plastic

We used straws to make holes for the key chains before they dried.  Our holes shrank as they dried, so beware!  They were barely big enough to be key chains once they dried.

You can paint your plastic to decorate it however you want.  We used acrylic paint.

Make your own plastic

What else can you do with homemade plastic?

  • Use cookie cutters to cut out shapes
  • Make magnets for the refrigerator
  • Make playing pieces for a board game

For more crazy science fun, check out our exploding chain reaction made with craft sticks!


  1. Kimberly says

    This looks so neat! Thank you for posting it!

    What kind of milk did you use (whole, skim, etc.)? Do you think it would make a difference?

  2. says

    Making plastic is actually on my science project to-do list. The recipe I found uses starch, glycerine, and vinegar. Milk and vinegar sounds much easier! Does it smell like cheese? I wonder how long it will take to break down. I think most biodegradable plastics stick around for a while, but I’m not sure how long.

    • SarahDees says

      It does not smell like cheese, thankfully! It smelled like vinegar, but dried with very little smell. Not sure how long it will last – I guess we’ll find out!

  3. Tori says

    This is exactly how you make what is called farmers cheese (minus a couple steps). It’s very much like ricotta, but not as dry. I never would have thought you could make cheese with it. We will have to try this.

    • Renae says

      Yep! I just experimented with it in the microwave and it worked great! I did discover that you have to have it molded before it gets very cool or it just crumbles. Don’t think you could reheat it, either.

    • Leighanne says

      Tried again, this time using the microwave and WHITE vinegar. MUCH better! I wonder if a higher fat milk would produce better results as our “cheese” didn’t stick together too well…

      • SarahDees says

        We used 2%. I wouldn’t think it would be that different from 1%, but maybe it is. Now I’m curious to try whole milk!

  4. Kelly Harris says

    I just have to say that I am new to having kids at home full-time (they previously went to daycare and I recently hired a nanny full-tim) and I LOVE your website! I struggle with creativity and you have the greatest ideas and ways to make home fun that won’t break the bank!


  5. Lorna says

    Did it not smell? We’ll be trying this today in Malaysia, so I’m a little bit worried that the hot climate here might not work well for the drying out process, but I’ll let you know!

  6. Mary says

    We just tried this with skim milk – it worked, but I think milk with fat will work better. We’re going to get some 2% and some whole milk and try different experiments. The skim milk made very little “plastic.” Will see how it goes once it dries. Thanks so much for this idea!

  7. Mattie says

    This appears to be more like dried out acid-set cheese as opposed to a more polymer style plastic. This is essentially how one makes paneer– an Indian cheese that has a the neat culinary property of not melting when heated during cooking.

  8. says

    Im currently an activity assistant at a nursing home. I surely can incorporate these ideas with my residents and have lots of fun and laughs. It will also help out our residents with motor skills and so forth !!! :-)

  9. Toni says

    After the milk separates it isn’t ricotta cheese it is actually an Indian cheese called Paneer. You strain it over night and then cut it into squares and fry it slightly. You can eat it that way but it is added to different Indian foods. :)


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