February 18, 2015

Frozen Rainbow Eruptions

In case you haven't noticed by now I have an obsession both with rainbows and also with baking soda and vinegar eruptions.  Rainbow eruptions make the most gorgeous eruptions ever.  Since we've had a heat wave I added a frozen element to the science play.

Gorgeous FROZEN rainbow eruptions - chilly science for kids

Fizzing Ice Rainbow

We have made rainbow eruptions before, and we love playing with rainbow ice.  I fell in love with these ice volcanoes from Reading Confetti, so I decided to combine the three ideas to make frozen rainbow eruptions.  Her frozen eruptions are different than these, so be sure to check out how she made her volcanoes.  Also, she has a great tip for getting the volcanoes to mold in a way that they will freeze just right. 

How to make frozen rainbow eruptions

How to Frozen Rainbow Eruptions

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Fizzing rainbow ice

Directions:  I used these spill proof paint cups to make my frozen molds that housed the rainbow eruptions.  I filled each cup with water, almost to the top.  Then I covered them with cling wrap before securing the lid in place.  The spill proof cap pushed the cling wrap down, creating a place for the baking soda to sit when we created our eruptions the next day.

While setting up our eruptions I pulled out the frozen cups and set them in the sink to thaw a tiny bit, just enough to remove them from the spill proof cups.  You could also run them under warm water to speed up the process. 

I set each ice mold on the ground and put a small amount of powdered tempera paint inside each one.  Food coloring, liquid watercolor paint, or regular tempura paint could be used instead, but I love the bright colors made by the powder.

Making rainbow eruptions

Then I covered the powdered tempera with baking soda.  I intended to make the color a surprise like with our color surprise eruptions, but the moment I started gathering supplies all of my boys crowded me and asked what we were going to do.  They saw me filling the ice with color and baking soda, and they even helped a bit.

Rainbow fun with icy eruptions

Once everything was set up I passed out squeezy bottles full of vinegar and let them have at it.  *Safety note*  Be sure your children know to aim down to avoid getting vinegar inside someone's eyes.

Frozen science for kids with fizzing rainbows

We've made some gorgeous rainbows in the past, but I think these might be my favorite.  Gorgeous doesn't even begin to describe the bubbling reaction.

Rainbow eruption sensory play

We refilled the ice molds and squeezy bottles several times, and each time the colors dazzled us all.

There was no need to add more color each time.  As the ice cracked, color dipped into the ice and produced gorgeous, fizzing rainbows every time.  I stock up on baking soda and vinegar at Costco, so this activity was inexpensive to do again and again.

Foaming rainbow eruptions

The ice blocks were fun to play with, too.

Frozen building blocks sensory play

Despite the fact that it's hot here, I think this would be an awesome winter activity.  If we lived where it snows I would have nestled the ice sculptures in the snow to do the whole activity.  The overflow of the eruptions would be gorgeous in the snow!

Fizzing ice rainbows - how to make colorful frozen eruptions

For more rainbow activities for kids follow me on Pinterest.

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Rainbow eruptions for summer with ice

More eruptions for kids:

How to make baking soda paint that fizzes, creating beautiful color mixing reactions.  Make moon rocks out of common household ingredients.  Once they are solid, kids will have a blast making them erupt and fizz!  Exploring color theory with baking soda and vinegar eruptions - simple science for kids!


  1. This looks so fun! Question: is it hard to clean up afterward? I'd love to try it, but we live in apartments and can't stain the sidewalks.

    1. As long as you use washable paints and spray it down before it dries, it should be fine. We've never had an issue with staining. However, to be safe I would test a very small area first. Another idea is to do it in a sensory bin to contain the mess.

  2. I love this. It may kill surrounding grass if done outside so be careful of that if that kind of stuff it important to you.

  3. Have you done it on paper? Just wondering what it would be like when it dried.


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