Fireworks in a Jar

If you have a little one who is fascinated with colors and fireworks, this simple experiment is for you (and your child).  The idea for this experiment originally came from Action Pack.  You most likely have everything you already need in your cupboard for these fireworks in a jar:  oil, water, and food coloring!  If you haven’t already, be sure to download my FREE Fascinating Science for Kids eBook with this experiment and 14 equally-engaging others!


1.  Fill your jar 3/4 of the way full with warm water.

2.  In a separate bowl, mix a 3-4 tablespoons of oil and several drops of different colors of food coloring (I used 4 drops of each color:  red, yellow, blue, and green).

3.   Use a fork to gently mix the oil and food coloring together.

4.  Gently pour the oil mixture into the jar.

5.  Watch what happens—the food coloring will slowly sink out of the oil and into the water.  When this happens, it will expand and begin to mix with the other colors.

The Science Behind It:

Food coloring dissolves in water but not in oil.   Because the oil is less dense than the water, it will float at the top.  The colored droplets will begin to sink because they are heavier than the oil.  Once they sink into the water, they will begin dissolving into the water (which looks like a tiny explosion).

Download your free Science eBook with this idea and many others by clicking below and entering your e-mail address.  You’ll immediately receive an e-mail that will have the link to the eBook!  If you would rather not be an e-mail subscriber, “like” us on Facebook and then send us a private message to claim your FREE eBook.


  1. Ashley says

    I tried this and it didn’t work?? What oil do you use??? one thing that worked is if you stir it with a fork you get a tornado.

  2. Amanda says

    We just tried this, this morning it was really good! my daughter (2) loved it. I used vegetable oil and it worked fine, i didnt measure the amount i just poured until i thought there was enough. The second time i only used two drops of blue and it was better cause we could see the other colours more. Thanks for sharing this idea.

  3. Kylie says

    Every time after we mix the oil and food colouring into the jar of warm Warter it just becomes black straight away? How do I stop that to get the coloured effect?

    • says

      It is a quick reaction, so it won’t stay “fireworks” for very long. I’m not sure why it is happening so fast for you, though. You could try altering the amount of oil you use or the water temperature?

  4. Sara says

    A nice idea, to do with the kids on new years eve, I don’t really like fireworks. But this makes a nice little homemade firework experiment. I guess we just have to make the sound effects ourselves :)

  5. Ryan says

    Brilliant experiment which we are going to use in the coming days as part of a STEM day we are doing for some year 6 students to explain reactions and liquid density’s.

  6. ziling says

    Hi dear, i could not download yr fantastic science pack.
    Could you send me the link or file.
    Thank you for sharing with us.

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