DIY: Milk Fireworks | Tinkerer Box Blog

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Milk Fireworks

Stem Activities

Ages: 3-5

Less than 30 minutes

Grownup needed

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Turn your kitchen into a laboratory and use baking ingredients to create your own underwater fireworks display! In this experiment, you'll learn about density.

Materials Needed

1 cup milk
1 cup water
Salt
Glass
3 bowls
Food colouring
Stirring stick
Dropper

An assortment of ingredients and tools are arranged on a light woodgrain table, likely for a science experiment or cooking activity. From left to right: a glass filled with milk, a glass of water, an empty cylindrical glass container, a stack of clear glass bowls with a small black measuring spoon inside the top bowl, three small bottles of food coloring (red, yellow, blue), a wooden craft stick, and a clear plastic pipette or dropper. A small glass beaker containing a white powder, possibly sugar or salt, is positioned in front of the milk and water glasses. The beaker has 80mm marked on its side.

Step-by-step tutorial

Step 1

Pour 1/2 cup of water into the glass, add one tablespoon of salt and stir well.

A hand holds a black measuring spoon filled with white granules, likely salt or sugar, over a clear glass containing water. The granules are being poured into the water, with some already visible at the bottom of the glass. The glass sits on a light woodgrain surface. This image likely depicts the process of dissolving a substance in water.

Step 2

Slowly pour the remaining water down the side of the glass into the salt water. Let it stand for 5 minutes.

A hand pours water from a clear drinking glass into a shorter, cylindrical clear glass on a light woodgrain surface. The cylindrical glass is already partially filled with water.

Step 3

Divide the milk equally between three bowls.

Three small, clear glass bowls containing milk are arranged in a row on a light woodgrain table. Each bowl holds a similar amount of milk. They appear ready for an experiment or recipe.

Step 4

Add different food colourings to each bowl of milk and stir well.

Three clear glass bowls containing milk sit on a light woodgrain table. Drops of blue, red, and yellow food coloring have been added to each bowl, creating distinct circles of color on the surface of the milk. A hand is shown in the process of adding yellow food coloring to the third bowl. This setup likely demonstrates a surface tension experiment or a colorful activity involving milk and food coloring.

Step 5

Use the dropper to add the coloured milk into the settled water solution.

A hand holds a clear plastic pipette containing yellow liquid, likely food coloring, over a clear glass partially filled with water. Droplets of the yellow liquid are being dispensed from the pipette into the water. The glass sits on a light woodgrain surface. This image likely depicts an experiment or demonstration involving color mixing or diffusion.

Step 6

Now watch as beautiful milk fireworks appear!

A clear glass sits on a light woodgrain surface, partially filled with water. Swirls of pastel colors—primarily yellow, blue, and pink—are diffused in the water, creating a visually appealing mixture. The colors appear to be slowly mixing and settling, suggesting a recent addition of dye or food coloring. This image likely depicts a science experiment or demonstration involving diffusion or color mixing.

The Science Behind It:

In this experiment, you're using four liquids with different densities: water, milk, food colouring, and salt water. Initially, water sits above the salt water because it has a lower density. Milk mixed with food colouring has a density greater than water but less than salt water, so when it's dropped into the dense salt water, it explodes like fireworks! After a while, you'll notice the milk floating in the middle of the solution.

You probably have many liquids of different densities at home. Under adult supervision, try mixing some liquids together and see which ones float and which ones sink!

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