Milk + Soap = Awesome Reaction




Introduction: Milk + Soap = Awesome Reaction

Great fun for kids and adults! Minimal set up and clean up makes this at home science / art project a real winner.

When you're done reading this instructable feel free to check out more of my how-to, life hack and DIY videos and articles by visiting my YouTube channel or website.

YouTube channel:

My website:

Step 1: Watch This Video!

Here you can see this awesome reaction happen right before your eyes!

Step 2: What You'll Need

The first thing you'll need is some milk. I've found that whole milk works best, but you can use any kind.

Food coloring will allow you to see what is actually happening and create beautiful swirls and patterns. Any kind, color or amount will work. Have fun experimenting!

To hold the milk, use a shallow bowl or a plate with raised edges.

Regular old dish soap is the way to go.

Finally some Q-tips to apply the soap with.

Step 3: Add the Milk

You won't need much at all. Just a thin layer of milk will do. Because so little milk is needed I poured mine into a plate with raised edges instead of a much deeper bowl.

Step 4: Prepare Some Soap

Pour some dish soap into a mug, glass or cup. As with the milk, you won't be needing much.

Step 5: Add Some Color

Now you can get down to the fun stuff! I started by adding four or five drops of purple, red, green and blue in the center of the plate. But as I stated in a previous step: you can use any colors you'd like. Have fun placing different numbers of drops in different areas of the plate to see what will happen.

Step 6: Watch the Science Come to Life!

Dip your Q-tip into the dish soap. You don't want a lot globbed on so wipe off some of the execs soap on the sides of the mug. Gently touch the Q-tip to the surface of the milk and watch as it quickly repels the milk and food coloring away from the area you've placed it.

Eventually the milk will become saturated and this will no longer work. However it will continue to have this reaction for quite some time. As you saw in my video you can wiggle and move the Q-tip to make interesting and beautiful patterns in the milk.

Step 7: How the Reaction Works

Milk is actually mostly water but it is also made up of vitamins, minerals, proteins, and tiny droplets of fat suspended in solution. Fats and proteins are sensitive to changes in the surrounding solution (the milk).

The secret of the bursting colors is the chemistry of that tiny drop of soap. Dish soap, because of its bipolar characteristics (nonpolar on one end and polar on the other), weakens the chemical bonds that hold the proteins and fats in solution. The soap's polar, or hydrophilic (water-loving), end dissolves in water, and its hydrophobic (water-fearing) end attaches to a fat globule in the milk. This is when the fun begins. The molecules of fat bend, roll, twist, and contort in all directions as the soap molecules race around to join up with the fat molecules. During all of this fat molecule gymnastics, the food coloring molecules are bumped and shoved everywhere, providing an easy way to observe all the invisible activity. As the soap becomes evenly mixed with the milk, the action slows down and eventually stops. Try adding another drop of soap to see if there's any more movement. If so, you discovered there are still more fat molecules that haven't found a partner at the big color dance. Add another drop of soap to start the process again.

Credit for this explanation goes to Steve Spangler Science

Step 8: Have Fun!

Here are some pictures I took while playing around with this. It really is a lot of fun, even if you're an adult.

I hope you guys enjoyed this instructable. If you know of other fun household science or art experiments please leave them in the comments. I'd love to hear them and I'm sure other readers will too.

Don't forget to check out the links to my YouTube channel and website in the intro section of this instructable if you'd like to see more fun stuff like this.

Have a great day!



    • Metalworking Contest

      Metalworking Contest
    • Fix It! Contest

      Fix It! Contest
    • Creative Misuse Contest

      Creative Misuse Contest

    25 Discussions

    The soap is changing the solution of the milk. The milk is mostly water but also contains proteins and fats. The characteristics of the soap cause the solution of milk (water, fats, and proteins) to break down. What you're seeing are the molecules of soap joining up with the molecules of fat in the milk. The food coloring just allows you to see the invisible molecules moving!

    Another demonstration similar to this uses water, a cereal bowl, soap, and paperclips. The challenging part is to try to float a paperclip on the surface of the water. (It's pretty tricky...the secret is to move slowly and to use a second paper clip to lower it into the water parallel to the surface) Once you have it floating, take some soap and put a little on the end of a q-tip. Gently (and I mean GENTLY) touch the the edge of the water with the soapy q-tip and you should see the paperclip sink immediately (you could also just add a drop of soap straight to the water if you're careful). Once again the soap is causing changes to the water. Here it reduces surface tension of the water. Water has cohesive properties (meaning the molecules kind of stick together) but the soap reduces water's cohesiveness (it breaks down the hydrogen bonds in water molecules).

    3 replies

    Nice Video. And now for my comment to the Nit Pickers.

    To the Nit Pickers: Why is a scientific explanation needed? Why not just enjoy the video, try it if you like it. Do your own research for the Science of it.

    3 replies

    What difference does it make, NO DIFFERENCE. Some people just cannot help being Nit Pickers. What happened to your post????????


    3 years ago

    this was really fun 4 me and instead I used gel food coloring but it still worked because I didn't have liquid food coloring so next time I need a science experiment then this is what I'm gonna do instead???????

    I think if you used liquid watercolour paint or dyes you could use this for interesting effects on marbled paper.

    That is Beautiful this would be A Good Science Project

    I know that we could simply google the science behind this, but would you mind adding some explanation to your instructable? It would really make it complete.

    I'll second that. Don't get me wrong, it's a great instructable and video but I'd prefer to know/learn why this reaction takes place instead of watching the pretty colours.

    1 reply

    the dish soap spreads on the surface on milk (milk is thick enough to hold it) and pushes the food coloring aout of the way.

    I guess if you gently laid a piece of paper on the surface and lifted off you could get a "print" of them

    Might look cool but would probably smell a bit when the milk went off

    I remember doing something like this in third grade! Anyways, nice instructable, and that main picture is excellent!

    I teach at an elementary school, and we used this as the basis for exploration at our math/science night. The kids loved it and I was surprised by it as well. Might also be good for exploring color mixing. Very fun!