Kinetic sand out of a tub costs a startling amount for how little you get. This version costs about the price of a bag of play sand and a box of cornstarch, and it does the same things: it flows, it clumps, and it holds a shape when you press it.
Miss Kate of Alameda Arts mixes a whole bin of it on camera using three ingredients and no slime starter, no borax and no glue. Five cups of play sand, three cups of cornstarch, one cup of oil. Most of the ten minutes is your hands in the bin, which is half the fun of it.
It is a good rainy day project and it is messy in the way kids like, so set up outdoors or on a drop cloth. For more of the same sort of thing, there is slime and playdough, or salt dough ornaments if you want something that dries hard and keeps.
Why the 5-3-1 ratio works
Each ingredient has one job. The sand is the body. Cornstarch is a fine powder that fills the gaps between grains. The oil coats both and makes the powder tacky, so the grains cling to each other but still slide.
Store-bought kinetic sand uses a silicone polymer to do that, which is why it never feels oily. Homemade is closer to moon sand. It packs and slumps the same way, and kids do not care about the difference.
Play sand vs craft sand
Use washed play sand from the hardware store. It is fine, clean and cheap by the bag. Coarse builder's sand will not hold a shape. Colored craft sand works but costs more and is often finer, so it can need a little extra oil.
How to color it
Start with colored craft sand, or stir powdered tempera paint into the cornstarch before it meets the sand. Two tablespoons gives a soft pastel. Skip liquid food coloring here. It beads up in the oil and stains hands.
The cornstarch and dish soap version
If you do not want oil in the house, mix 2 cups of sand with 1 cup of cornstarch, then add a tablespoon of dish soap and a few tablespoons of water. Add the water slowly. This one is softer and dries out within days, so it is a make-and-play batch rather than one you keep.
Storing and reviving it
- Keep it in a lidded bin or zip bag so dust and pet hair stay out.
- Gone crumbly? Rub in a teaspoon of oil at a time.
- Greasy or sticky? Work in a spoonful of cornstarch.
- Cooking oil can go stale after a few months. If it smells off, mix a fresh batch.
Is it safe for toddlers?
The ingredients are kitchen staples, but sand is not food. Supervise little ones who still put everything in their mouths, keep it away from eyes, and play over a tray. Use a different oil if anyone has an allergy to the one in your cupboard.
Common mistakes
- Too wet and sticky. All the oil went in at once. Add cornstarch a spoonful at a time.
- Crumbly, will not mold. Usually under-mixed, not under-oiled. Keep rubbing before adding more.
- Dry pockets at the bottom. Lift from underneath. Cornstarch sinks.
For another one-bowl sensory mix, try oobleck.
