Introduction: Plastic Milk

Picture of Plastic Milk

I was trying to find a recipe I could use to produce a chemical reaction for the Mad Scientist contest and the chemical reaction contest. I came across this one and thought is was interesting. For this tutorial I will be making Plastic milk.

Step 1: Recipe

Picture of Recipe

Recipe ingredients:

  • 2 Cups Milk
  • 2 Tablespoons white vinegar

This recipe came from here:

It is very helpful to view this video so you can see the process of making plastic milk.

It is a quick and easy project.

Step 2: Utensils

Picture of Utensils

Utensils needed:

  • Liquid measuring cup
  • Measuring spoons
  • Coffee filters to absorb the liquid
  • Fine weave strainer
  • Spoon
  • Plate
  • Pan
  • Cookie cutters
  • Skewer not shown
  • Wax paper not shown, line the plate with wax paper.

Step 3: Measure/ Heat

Picture of Measure/ Heat


  • Measure 2 cups milk and set aside.
  • Measure 2 Tablespoons white vinegar and put it into a small glass reserving until later.
  • Line the strainer with 2-3 coffee filters or paper towels.
  • Line the plate with wax paper.

Pour the milk into the pan and heat on stove. Do not boil! Heat until almost too hot to touch but not boiling

  • Add vinegar.
  • Stir gently.
  • Allow it to separate into globs.
  • Stir again.

Step 4: Strain

Picture of Strain

Remove from the stove:

  • Place strainer in sink.
  • Pour Contents into the lined strainer.
  • Allow to drain a couple of minutes.
  • Carefully pull up the filter and gently press with your fingers to remove liquid from ball.
  • You might need to place it in another doubled coffee liner and squeeze again to remove excess moisture.
  • It should begin to form a paste.
  • Let it set 5 minutes.

Step 5: Molding

Picture of Molding


  • Gently roll the plastic in a tight ball.
  • Gently press flat to form shapes.
  • This part is tricky you need to work with it and try to keep it together nicely.
  • You accomplish this by pressing down and pulling toward the center with your hand.
  • Using the cookie cutters make the shapes.
  • Form a couple of balls if you desire.
  • Using the skewer poke holes where you want if you are going to make jewelry.

Step 6: Place Shapes on Plate

Picture of Place Shapes on Plate

Place the shapes on the plate lined with wax paper:

  • Place the shapes on a plate.
  • Set in a safe warm area away from children and pets.
  • Allow to dry
  • Turn over after a few hours to allow the back side to dry.

Please note: I made a ball because they mentioned it was rubbery and I thought I would see if it bounced. We will see.

Step 7: Uses

Picture of Uses


  • Allow to completely dry before working more with it.
  • You can make shapes from the plastic clay.
  • Paint it when it is dry.
  • Write on it.
  • Make jewelry.
  • If you can mold a perfect circle it bounces.
  • Embellishments for many things.
  • Gift tags.
  • Dog Tags.
  • Key ring tag.
  • Picture frames?
  • Dolls.
  • Game pieces.

This list is very long.
I can't wait until the paint dries so I can create something that I will post here when it is done.

Step 8: Sunshiine's Final Thoughts

Picture of Sunshiine's Final Thoughts

This was a fun experiment. It would make a great craft project for the family.
What I did was turn milk into a solid through a chemical reaction known as a polymer molecule strand.
The individual protein strands within the milk and the vinegar solidified making plastic.

The plastic is based on a protein called casein - adding the acid causes it to unfold from its usual tangled form,and change into longer sections, which are the lumps that are removed to form the ball .
Casein-plastic used to be used to make shirt buttons.
Some cheeses (like the processed cheese slices) are made in a very similar way, so can be genuinely called "plastic cheeses".
I Painted the shapes thinking I would glue them on boxes for embellishments or make jewelry. I am very happy with the results.

Thanks you for stopping by and please check back soon as I am working on some interesting things to share.

Have a nice day!



desigellert (author)2016-11-30


dragon fllyer (author)2015-01-12

What this really is is cheese...

celec (author)dragon fllyer2015-03-25

This recipe is false, but with a spoon of caustic soda, this recipe became a real plastic, the galatite.

EgbeE (author)celec2015-12-28

can you tell me how it turns to plastic I need it for an expirament

sunshiine (author)EgbeE2015-12-28

This link explains the process fairly well. Hope this helps. Good luck on your assignment. sunshiine~

ShinyK (author)2015-11-10

Hi, I prepared the clay yesterday night as you mentioned but it is not like a ball as you shown in the pic. it is coming like small pieces. i unable to do the shapes with it. how can i get it smothly? is it the same as plastic clay? or both are different?

I want to make jewellery with the caly.

sunshiine (author)ShinyK2015-11-10

Hi ShinyK,

I edited the pictures so hopefully you can tell what the mixture looks like. This was an experiment for a contest. I understand your interested in making jewelry. I made this several years ago and don't remember a lot. I do remember that this is not a mixture like play dough or pie dough. It resembles cottage cheese and in order to get the shapes I needed, I used tiny cookie cutters or molds and shaped the tiny balls by hand and very carefully removed the shapes using a tooth pick. If I recall I don't think you could make a very large ball by shaping it with your hand. The clay is made up of a lot of small pieces and did not have an elastic type texture like molding clay. Perhaps if you let it dry longer it might be easier to work with. After all this time the small shapes I made are still holding up and I am happy with them. I do think that there are more suitable recipes for jewelry that is cheap to make. What type of clay are you looking for? I might have something that would work better. Or If I were to try this project again I might use flour to try and bind the pieces together a little tighter; if that makes since. Or I might even try to work in some glue to make it more flexible. I hope this helps. I wish you the best and hope it works out better for you.


Ftnsbi (author)2015-04-01

why is it not edible ??

sunshiine (author)Ftnsbi2015-04-02

It is very very hard like plastic. It probably would not taste good at all. I hope this helps. Have a great day!

gravityisweak (author)2014-08-05

Ok so I'm curious. If you start with milk, and add vinegar then remove the casein, what do you have left? Is it still milk? Or milky vinegar? Or something new altogether?

sunshiine (author)gravityisweak2014-08-06

Hmmm, the best I can describe it would be a jell-0 type of substance that is not completely set up. It is still very soft and mushy but as it dries it firms up. At this point one could not make a shape from it because it will not hold. Hope this helps. Thanks so much for stopping by and do have a splendorous day.

EmiClarice (author)2014-06-07

Then, I looked at this instructible and saw what I did wrong. Thank you!!

sunshiine (author)EmiClarice2014-06-07


EmiClarice (author)2014-06-07

OMG I remember doing this in a science after school program! Mine turned out like feta cheese.. :)

sunshiine (author)EmiClarice2014-06-07

Yes, it is a lot like feta cheese but if I recall I kneaded it a little to form a ball. Thanks for stopping by and commenting and do have a great weekend.


akshat21045 (author)2014-02-26

Is it edible? Just asking...

sunshiine (author)akshat210452014-02-26

No it is not edible. Thanks for stopping by and have a great day.

akshat21045 (author)sunshiine2014-02-26

Oh. Thanks in advance.

sunshiine (author)akshat210452014-02-26

You welcome.

electricitis (author)2014-01-04

This molds and gets pretty gross after a while. :P

and when it grows mold it STINKS!!!

sunshiine (author)electricitis2014-01-17

Thanks for commenting but I have had mine for over a year and it has not molded. Weather may be a factor as I live in a dry climate.

nathanielmynhier (author)2013-12-29


kikilovesyou123 (author)2013-09-30

thanks alot ghys i really liked it this is for my scince project

sunshiine (author)2013-06-18

Thanks for sharing! This was a fun project! Have a splendorous day!

them8triark (author)2013-04-07

with this, are you able to finely sand the pieces if you want to?

sunshiine (author)them8triark2013-04-07

I have not tried that but I would think you could. What is difficult is molding the pieces because it does not stick together like clay. I only made these one time. Maybe adding something that would stick to the milk better so you could mold it more smoothly? It doesn't hurt to try different methods. I hope this helps! I enjoyed making these! Thanks for asking and do have a splendorous day!

FrozenIce (author)2013-03-01

Woohoo for the cross!

sunshiine (author)FrozenIce2013-03-01

Thanks for stopping by and commenting! Have a splendorous day!

FrozenIce (author)sunshiine2013-03-02

Thanks! By the way, your name reminded me of a song:
Thousand Foot Krutch- Sunshyne

sunshiine (author)FrozenIce2013-03-04

Checked out the song! Thanks so much for sharing!

Moco cochino (author)2012-11-25

Can yuo tuoch the plastic to molde it?

sunshiine (author)Moco cochino2012-11-25

Maybe if you allow it to dry a while because this is not as firm as clay. I hope this helps and thanks for commenting!

Moco cochino (author)2012-11-25


ChrysN (author)2012-08-25

Hi, Sunshine, Congrats on being a runner up winner! I was wondering if you can use expired milk? I have some in the fridge right now that ruined my morning coffee, but I thought that since there is quite a bit left to make some plastic from it.

sunshiine (author)ChrysN2012-08-25

I forgot, I think the best way to do this is just follow the instructions. I was thinking your milk was clumpy already but no, just follow these instructions and it should be fine. Sunshiine

ChrysN (author)sunshiine2012-08-25

Thanks, I will give it a try and let you know how it turns out!

sunshiine (author)ChrysN2012-08-25


ChrysN (author)sunshiine2012-08-26

It worked fine. Once I started heating the milk it already began to separate. I still added the vinegar though. I was worried that it might be stinky but it didn't smell very much and once it dried, it didn't smell at all.

sunshiine (author)ChrysN2012-08-25

Hi CHRYsN! I am pretty sure that will work. Just follow the directions except omit the vinegar. Please let me know how it turned out if you make it and I will add that information to my instructable. I just don't see why it wouldn't work. Have a great day and thanks for stopping by! Sunshiine

babelsgp (author)2012-01-27

Congrats! I noticed that you also wanted to paint what you create, I wonder if the paint made from milk would adhere to itself?

sunshiine (author)babelsgp2012-06-16

Might be worth a try! Thanks for sharing!

babelsgp (author)babelsgp2012-01-27

Possibly before the plastic dried?

kristinsilver (author)2012-05-02

In reading through many of the comments, I didn't see anything regarding the smell. I am thinking about doing this for a scientific art project for kids, but want to avoid a room full of drying expiring milk stench. How stinky is it when it dries?

sunshiine (author)kristinsilver2012-06-16

I apologize for not answering this question sooner but my PC died. I would think it might be offensive if you had 30 of them but thought of a possible solution. Perhaps drying them in sand covered in a box with air holes at the top might work. A simple experiment might be worth it. Thanks for commenting and have a nice day!

techturtle2 (author)2012-05-29

Can you speed up the drying process by heating/cooling the plastic?

sunshiine (author)techturtle22012-06-16

I am sorry it took so long to answer this question. My Pc died. I would think a fan blowing on it or heated in the oven might help. I am sorry I can't answer your question better. Thanks for commenting and have a nice day!

phanalax (author)2011-12-31

Ok, for all of you who don't know what you're talking about, this is not cheese. there is a chemical called casein within milk which is very similar to the long polymers in plastics you see today. once formed it makes A knid of plastic called galalith: , so yes this is a real plastic.

babelsgp (author)phanalax2012-01-27

Casein has lots of uses, from glue to paint to plastic AND cheese. Cheese is produced by coagulation of casein Paneer, an Indian cheese, really is made in this fashion, they do not use rennet or anything else to solidify the casein, like most cheeses are. They just acidify and separate the milk, pull off the curds aka casein and flatten and fry and go! Very tasty I might add.

sunshiine (author)phanalax2012-01-02

Thanks for the information! I appreciate your comment!

About This Instructable




Bio: I am married with two children. Spring, summer, and fall are my very favorite times of the year. I love the sunshine thus the reason ... More »
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