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Science Rocks!

Plastic Milk


your results

Sent in by:
Jodi of NS

Turn milk into a solid!

Materials Needed

  • skim milk
  • white vinegar
  • microwave proof bowl
  • strainer



  1. I bet you've heard the nursery rhyme "Little Miss Muffet." Remember how she sat on her tuffet eating her curds and whey? But, do you know what curds and whey are?
  2. Here's a fun way to find out:
  3. Check with a grown-up before you begin.
  4. Add 4 teaspoons of white vinegar to 1 1/2 cups of skim milk.
  5. Microwave the mixture for about a minute. If you're not allowed to use the microwave, be sure to ask an adult to help you.
  6. After a minute, the milk and vinegar will be separated into two parts, a liquid and a solid.
  7. Here's what happened to the milk. By adding the vinegar, you have created a chemical reaction that separated the milk into two parts, a solid-the curds-and a liquid-the whey.
  8. Now, when you stir the milk, the curds become a "blob."
  9. When you strain the liquid off, you can make the blob into one big lump.
  10. Let it cool off, and then you can play with it. It feels like rubber. The protein in the curds is what makes it act like rubber.
  11. You can form the blob into shapes. If you leave it out, it will harden.

A hundred years ago, people took milk and used it like this to make plastic. Can you think of any other liquids you can separate into parts? Experiment and send your results to ZOOM.

Some of your Results

Julia, age 12 of Princeton, NJ wrote:
I used this for my science project on plastic!!! It was so cool!! It smelled really bad... but I got an A!

Leilani, age 10 of Hollister wrote:
the plastic milk was the best it realy did seperate!!!

Angelina, age 11 of Lake Charles, LA wrote:
I loved it but the milk kinda smelled.

Samantha, age 8 of Douglas, AZ wrote:
It didn't work out because it fell apart but it was pretty fun.

Nicole, age 9 of New York wrote:
this experiment im still working on it but it is going out to really cool I love this experiment!

Aaleen, age 10 of Al Ain wrote:
the milk went all hard it was seriously wierd

Tony, age 11 of Dallas, TX wrote:
It was so cool! I decided to use this for my science fair project.

Federico & Giorgio of Varese wrote:
It smelt very bad. we are from italy and we are excited to do this experiment. we had a lot of fun

Karla, age 9 of Chicago, IL wrote:
it was so COOL. I trik my mom so she seid AAAAh WHAT IS THIS.

Adriana, age 10 of Coushatta, LA wrote:
well, the plastic milk experiment was a good project. the plastic felt cool and im doing this project for the science fair

Xiomara, age 10 of Weslaco wrote:
It became solid SO COOL

Katrina, age 13 of Boston, MA wrote:
i tried it but then I had to heat it for another minute it is really cool and im glad I tried it!

Hannah and Jackson of Reedley, CA wrote:
The milk turned cloudy when we poured the vinegar in. We put it in the microwave for a minute and fifteen seconds. The curds kind of looked like clouds in the water, but then we reached in and saw that they weren't liquid.

Jacob & Audrey of Lexington, KY wrote:
It was weird because it was squishy, we had fun!

Gello, age 12 of MO wrote:
The experiment worked, when I was about to mix the vinegar with the milk I got excited, fortunately it worked. The mixture turned into a rubbery stuff, that was pretty awesome.

Jack & Nolan, age 6 of Clovis, CA wrote:
When we did this experiment, it smelt really bad, but was totally awesome. We really liked playing with it. It felt like cottage cheese. So fun!!!

Maddie, age 12 of Grapevine, TX wrote:
it was cool. the milk terned like cottege cheese. well thats what it felt like.

Ellenie, age 8 of CA wrote:
It was really smelly and gushy at first, but I got used to it.

Science Club, age 8 of Hidalgo, TX wrote:
We used 1% milk and we got about 4 tbs of solid matter.

Caroline, age 13 of AU wrote:
it worked! though it smelled and I had to keep squeezing liquid out of the clumps... and it dried faster...yay! I first put it in for 1 min then 30 secs then another 30 secs then 45 secs... it worked easier and I used sushi vinegar...

Owen, age 9 of Hummelstown, PA wrote:
The milk and vinager seperated. It looks so cool. My favorite expierament is cleaning the penny.

Kristian of Port Colborne, ON wrote:
I am doing this for a science fair project! this is fun to do!!!

Emmanuel, age 13 of Harvey, LA wrote:
After you mix all the component together it froms a design, which make the milk go to the bottom and the vinegar raise to the top. The stirring had my hand and arm tired. It took 2 to 3 hours to get hard. Oh! It smell bad.

Ryan, age 9 of Shingle Springs, CA wrote:
The plastic milk clumped up really good. The smell wasn't too bad. I had a lot of fun playing with the curds. It feels like plastic and rubber.

Jessi, age 13 of Belle Chasse, LA wrote:
The skim milk smelt the worst, the 1% was the best we thought, 2% and whole milk produced the most, but was the bumpiest.

James, age 9 of CA wrote:
it was a success but it smelled bad!

Alasia, age 12 of Detroit, MI wrote:
This project was really interesting. The smell was strange-you know in a scientific way. It was fun experimenting with a new kind of idea. I never even heard of turning milk to plastic before this. Very helpful!!! Very fun!!!

Kyndall, age 11 of Compton, CA wrote:
It got hard after a while.

Erika, age 9 of TX wrote:
it stuck together becuse the milk was so slippery. and when you put the plate on the bottom of the project we put the cookie cuter and it became a circle.

not yet implemented