The best homemade slime recipe!

Experimenting with polymerization

We tested dozens of homemade slime recipes, and this was the best! Grab some glue and watch how a simple molecular process called polymerization turns sticky glue into ooey goo!

Ages: 3 and up (with a parent helping)

slime on hands

slime stretched out

How to do it!

Materials (What you’ll need)

  • 0.5 c glue (Elmers or similar)
  • 0.25 c water
  • few drops food coloring
  • 0.5 Tbsp baking soda
  • 1 Tbsp contact solution (add in two batches)

Materials: glue, contact solution, baking soda, food coloring

Mixing the slime

Method (What to do)

Mix glue and water, food coloring, and baking soda. Mix well.

Add .5 Tbsp contact solution and mix well again.

Then add another .5 Tbsp contact solution.

Tip your slime onto a table and knead by hand until it stops sticking to your hands.

Now you’re ready to play around with you slime! make it drip, drop, bounce, poke it, scoop it, and see what happens! How is this texture different from glue in the bottle, or glue after it dries?

How it works:

Glue has an ingredient called polyvinyl acetate (Poh-lee-VY-nul As-suh-tate), which has a molecular structure that looks like long strands. When it’s fresh out of the bottle, the strands can slide around making it a liquid.

Glue normally works the way it does because when the water between the strands of polyvinyl acetate evaporate, the strands stick to each other and everything around them in a solid mass.

Our reaction does something a bit different. We add contact solution, which contains boric acid. When boric acid is added to polyvinyl acetate, it makes the strands create cross-links with other strands. This still lets the strands slide around a bit, but not so much that they’re liquidy. This linking is called polymerization. The result is a rubbery, pullable, squishable, gooey material!

Slime is a type of substance called a non-Newtonian fluid. You can find out more about the science of polymerization and the properties of non-Newtonian fluids in this video.

Troubleshooting and tips

  • If your slime isn’t particularly slimy – it may not be mixed well enough. Give it a good stir or knead it more by hand.
  • Slime on clothes - soak in warm water with a bit of vinegar before washing.
  • Want to store it? Your slime should fit perfectly in any 8 oz. container (like a small takeout tub).