Magic Milk Fireworks – Kids Love This Activity!

Kids are fascinated when they see common substances do uncommon things. Mixing milk, soap, and food coloring to create milk fireworks is a  favorite project.

This chemistry activity can be enjoyed by preschoolers through teens. In fact, there are several chemistry lessons in this milk “fireworks” activity that older students will understand.

Our preschoolers enjoyed the color mixing and immediate reaction when the soap and milk mixed. They loved the patterns made and got a thrill from making new colors as the food coloring mixed. They also understood the cause and effect of the soap causing the milk and colors to move and mix.

It’s so fun to make an artistic design in the milk with the food coloring before adding the soap. (I recommend using Dawn or a store brand of Dawn.)

A Few Tips for the Milk Fireworks Activity

• Allow extra time for your children to experiment with this activity. Once they make magic milk fireworks for the very first time, they are going to want to try it again, and again, and again. It’s so much fun to arrange the food coloring drops in different patterns and then dot the soap in varying locations to make even bigger milk fireworks.
• Take a video of some of the exploding milk fireworks and play it back in slow motion or record it in slow motion on a phone.
• Food coloring can get messy. Either have disposable gloves on hand for small hands, or…we discovered that mixing baking soda and vinegar on stained fingers will remove the food coloring. It does take a little elbow grease!
• Wear old clothes. Again, food coloring stains. This is such a fun activity, our preschoolers had a blast mixing the colors.
• Set up your area for mess so your children can enjoy the color mixing and creating chemical reactions. We did this outside, wearing play clothes, and used dollar store foil sheet pans to contain the liquids. As you can see from the photo below, lots of mixing went on. This pretty color blue was just one of the results :).

The Chemistry Behind the Milk Fireworks Experiment

First, we need to discuss the surface tension of water because milk contains a large amount of water. Water molecules like to stick together. On the surface where the water meets the air, water molecules cling even more tightly to each other. This causes a “skin” to form on the surface of the water. This skin is so strong that it can hold a weight that normally would sink in water. This is called surface tension. You can read more about the properties of water here.

Milk also contains fat, proteins, vitamins, and minerals spread throughout the water. Milk is a colloid which means means the molecules of the substance are mixed together but not combined.

The dish soap is a surfactant. Surfactant means “surface-active agent.” These substances have the ability to interrupt the surface tension of liquids.  A soap molecule has one end attracted to water molecules and the other end attracted to fat. So, when the soap mixes with the milk, the surface tension of the milk is interrupted and the milk particles move making the milk fireworks!

Turn the Milk Fireworks Activity into an Experiment

Turn this fun science activity into an experiment with one of the following ideas:

• Try making milk fireworks with different types of milk: chocolate, 2%, 1%, Half and Half creamer, buttermilk
• Before touching the Q-tip to the milk, sprinkle pepper on the milk. What happens? (Breaking the surface tension with the soap, makes the pepper move.)
• Instead of dish soap, try dipping the Q-Tip in cooking oil, vinegar. Have your children select other substances to use (mouthwash, pickle juice, etc.) Have them record what they think will happen and what actually happened.

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