Bubbling Slime Recipe for Sensory Tubs

These bubbling slime sensory tubs are my son’s new favorite thing! Which is pretty impressive, because in the past he’s always refused my invitations to play with the various gooey slime recipes I’ve experimented with in our kitchen. But between the exciting bubbling action that lasts for hours and hours — ours was still bubbling the next day! — and all of the pretend play possibilities, he’s been willing to get his hands messy to play. He’s also enjoyed making this no-cook slime recipe with me, and keeps brainstorming more Star Wars sensory tubs for us to make in the future.

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This slime recipe is made entirely with edible ingredients, and the key to it is xanthan gum, a common ingredient in gluten-free baking. It’s an ingredient I’ve been intrigued with ever since I made vegetarian marshmallows for my food blog. (That was a science experiment all on its own!)

I’ve been playing with xanthan gum slimes on and off for the past several months, but never blogged about them because a) I was the only one playing with them in our house and b) it was a bit difficult to work slime into the prevailing theme over at Play Trains! Wooden trains and slimes don’t exactly mix, you know.

But then Asia from Fun at Home with Kids held her awesome Slime Week, and she inspired Mary Catherine from Fun-a-Day! and me to come up with Star Wars slime activities. If anything was going to convince my son to play with slime, it would be making Yoda’s swamp come alive for him. Really alive…bubbling with life, in fact!

The bubbling action is caused by a thin layer of baking soda at the bottom of the sensory tub. With the slime at just the right consistency, it slows down the reaction between the vinegar in the slime and the baking soda at the bottom of the tub. For us, they kept reacting for at least 24 hours! My son was super impressed by that one, and it was a great way to observe baking soda and vinegar reaction over a long period of time.

Of course, you can stir the slime and the baking soda up and speed up the reaction, like we did above. (Make sure you’re prepared for overflow!) But even then it lasts much, much longer than plain baking soda and vinegar, and the slimy foam holds the bubbles for a long time.

And this is what Yoda’s swamp looked like when it was finally finished actively bubbling. All those trapped bubbles! Isn’t it gorgeous?

We made another batch of the slime earlier today, this time tinted blue, and put it in a squirt bottle. We set up a container with some Angry Birds figures sitting on baking soda, and he had a great time squirting the birds and pigs “at the pool”. We’re looking forward to finding more fun ways to play with this slime!

Safety Note: While all of the ingredients are edible, and this should be safe enough if a child tastes it once or twice, xanthan gum is a substance that thickens water. To be on the safe side, I wouldn’t let a child eat the slime, and I would supervise any activity where this slime is used.

Bubbling Slime Recipe

Ingredients

• 2 cups of white vinegar
• 1 1/4 teaspoons xanthan gum
• Food coloring (optional)
• Enough baking soda to cover the bottom of your tub

Directions

1. Pour the vinegar into a bowl. Whisk vigorously as you shake the xanthan gum over the surface of the vinegar little by little. Add food coloring, if desired, and whisk it in.
2. At this point, your slime will have lots of little white clumps of xanthan gum in it (see the photo below). These will slowly hydrate, so put the slime in the fridge for 2-3 hours or overnight.
3. Whisk the slime until it’s smooth. It should be cloudy, and the texture should look almost creamy. But gooey.
4. Test the consistency by lifting some of the slime up on the whisk and letting it run back into the bowl. If it’s too thick to run and pour, whisk in a little extra vinegar to thin it out.
5. Pour the slime over the baking soda in your tub and enjoy!

Notes

• Store the slime covered in the fridge. Because it’s made with edible ingredients, wouldn’t keep it around for more than a week or so.
• Xanthan gum is relatively easy to find these days, because it’s become a common ingredient in gluten-free baking. If you’re looking for more ways to use it, check out our Chocolate Slime Playdough recipe, and Fun at Home with Kids’ awesome No-Cook Edible Chia, Flaxseed, and Seedless Slime recipes. Also, back in my food blogger days, I wrote about vegetarian marshmallows I made with xanthan gum instead of gelatin.

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See it in Action!

Now that you’ve seen how to make the bubbling slime, see how we used it in our Lego Star Wars Yoda’s Swamp Slime Sensory Bin — you don’t want to miss the video!