top of page

A Colorful Way to Explore Science at Home: Create Your Own Rainbow Density Jar

  • The STEAM Generation
  • Nov 20, 2025
  • 3 min read

Updated: Dec 1, 2025


Creating a Rainbow Density Jar is a magical, hands-on activity that teaches children an essential science concept—liquid density. This project is not only educational but also results in a beautiful layered display. It is perfect for parents looking to spark curiosity and support learning at home.


⭐ What Is a Density Jar?


A density jar is a clear container filled with liquids of different densities. Each liquid has a different weight (mass per unit volume), allowing them to form layers without mixing. Kids can experiment, observe, and ask questions—just like real scientists!


🌈 Materials You'll Need


To create your own rainbow jar, you will need:


  • 1/4 cup honey

  • 1/4 cup light corn syrup (add 3–4 drops of blue food coloring before pouring)

  • 1/4 cup dish soap (green works best)

  • 1/4 cup water (mix with 3–4 drops of red food coloring)

  • 1/4 cup vegetable oil

  • 1/4 cup rubbing alcohol (mix with 3–4 drops of purple food coloring)


You will also need:


  • A tall, clear jar or vase

  • A spoon

  • Food coloring (optional but fun!)

  • A steady pouring hand or pipette


✨ Step-by-Step Instructions


1. Start with Honey


Pour 1/4 cup of honey into the jar. This is your densest liquid, so it belongs on the bottom.


2. Add Colored Corn Syrup


Gently pour 1/4 cup of blue corn syrup down the inside wall of the jar or use a funnel. Pouring slowly prevents mixing.


3. Pour in the Dish Soap


Add 1/4 cup of green dish soap directly into the center of the jar.


4. Add Colored Water


Mix water and red food coloring, then pour slowly down the side of the jar.


5. Pour Vegetable Oil


Add 1/4 cup vegetable oil. You’ll notice it sits nicely on top since oil is lighter than water.


6. Finish With Colored Rubbing Alcohol


Carefully pour 1/4 cup purple alcohol using a pipette or pour slowly onto the back of a spoon. This helps prevent the alcohol from mixing with the oil.


🎉 Science Behind the Rainbow


Each liquid has a different density. Heavier liquids sink to the bottom while lighter liquids float to the top. Use the keyword anchor text “density for kids” to help your child understand that density means how tightly packed the molecules are.


🌊 STEAM Spotlight: About Marine Engineering


Have you ever wondered how massive ships float, how submarines rise and sink, or how underwater robots explore the ocean? These are all challenges solved by marine engineers.


What Marine Engineers Do


Marine engineers design and build:


  • Ships and boats

  • Submarines

  • Offshore structures (like oil rigs)

  • Underwater exploration equipment

  • Renewable ocean energy systems


How Density Connects to Marine Engineering


Understanding density is critical in marine engineering! Engineers must calculate the density of:


  • Water (saltwater vs. freshwater)

  • Ship materials

  • Cargo weight

  • Air tanks inside submarines


These calculations help ensure structures can:


  • Float safely

  • Submerge when needed

  • Resist pressure in deep water

  • Stay stable during waves and storms


By making a Rainbow Density Jar, your child is using the same scientific thinking real marine engineers apply every day!


🎨 Extend the Learning

Here are some questions you can ask your child:


  • What happens if you shake the jar?

  • Which layer is the heaviest? Why?

  • Can you predict what will happen if we change the order of pouring?


You can even challenge them to test other liquids: maple syrup, milk, soda, etc.


🚀 Ready to Spark More STEAM Learning?

If you enjoyed this activity, join us for more hands-on STEAM fun through The STEAM Generation’s classes, camps, and workshops!


👉 Visit our website or enroll your child today to keep the learning adventure going!


For more engaging STEAM activities and programs, check out https://steamgeneration.org/steam-programs.


Remember, learning is an adventure, and with a dash of creativity, it's also a whole lot of fun!

Comments


bottom of page