We’ve been having fun with lots of different artistic science experiments lately, and this beautiful marbled milk experiment is no exception! I first remember doing this for an elementary school science fair, so long before the days of Pinterest this fun activity has been amazing kids! With only three ingredients involved, this is a great winter boredom buster with a few learning objectives thrown in to boot!
Firstly, gather your supplies, you’ll need:
- A shallow dish
- Q-tips or toothpicks
- Dish soap or detergent
- liquid watercolors or food coloring
- Milk (milk with higher fat content will work better)
Pour a little milk in to the bottom of your pan, a centimeter or so to cover the bottom of the dish. Next, drip several drops of food coloring throughout.
Then, coat your toothpick or q-tip in the soap, and let the kids place it in the milk. Immediately you will see the milk move and the colors begin to swirl. You can also use your toothpick to manually swirl your colors, or use a dropper to drip drops of soap straight in to the pan!
What happens when you introduce the soap to the milk is threefold. The soap reduces the surface tension of the milk, so that the liquid moves about more easily. The soap also reacts with the protein in the milk, changing its shape and setting it in motion. And, a reaction happens between the fat in the milk and the soap to form miscelles, this is how detergent is able to lift grease and stuck on food from our dishes!
Since it’s nearly St. Patrick’s Day, we’ve been focusing on lots of colorful activities, so I wanted to use this experiment to introduce the kids to color theory.
Once you finish with one batch of marbling, dump the milk out and start again! After we swirled our first batch of colors, I wanted to show them in a hands on way what happens when you mix two primary colors. In went our drops or red and blue, and out can a beautiful marbled purple!
You can set it up with two primary colors or all three in the pan, we did it both ways and had lots of fun experimenting with the swirling!
A great add on activity for this magic milk is to make prints of the artistic marbling patterns you make. Babble Dabble Do has a great tutorial for doing this! I definitely recommend using watercolor paper like she recommends. We tried with rice paper, which is really absorbent, and found that it tore way too easily.
This activity really helped my two and three year olds cement in their minds what happens when you mix red+yellow, or blue+yellow, or blue +red, they’re on a color mixing roll!