I have lost count of the rainbow activities I’ve set up over the past few years. Loose parts rainbows, alphabet pasta rainbows, edible rainbows, stack-a-stone rainbows. Whenever I think I’ve exhausted the idea, the kids find another way to play with one. This time I wanted something taste-safe enough that the youngest could explore it without me hovering. Taste-safe means every ingredient on the tray is something a child can put in their mouth without harm. Best for ages eighteen months to six, though older children stay engaged when given the masher and the alphabet-shape variation later in the post.
The answer turned out to be cooked, dyed mashed potato. Seven colors, one big shallow tray, and a potato masher.
Resources needed for Taste Safe Rainbow Sensory Play
- About five pounds of white potatoes (enough for two trays)
- Concentrated gel food coloring in red, pink, orange, yellow, green, blue, and violet. If you would rather skip gel, the kitchen-cupboard route is turmeric for yellow, beet juice for pink and red, red cabbage water with a pinch of baking soda for blue, spinach water for a softer green, and blueberry juice for purple. The colors come out gentler than gel, which actually photographs better in some light.
- A few saucepans, a colander, a potato masher
- A wide shallow tray or storage box with a flat base
How to make Taste Safe Rainbow Sensory Play
I peeled and cubed the potatoes first, then split them into seven small piles. For each color I added a few drops of gel into a saucepan of water and brought it to a boil before tipping the potato cubes in. The water dyes the potato as it cooks, far more evenly than mixing color in afterwards. Do not add salt to the boiling water if the children are likely to taste the finished tray.
I could only cook four colors at one time, so the rainbow happened in two rounds. Once a color was tender I drained it, placed the colored potatoes on a plate to cool, and laid the colors out in arc order along the tray.
The colors were brighter than I’d expected. Whether they would stay that bright once small hands got involved was another question.
Ways to play with Taste Safe Rainbow Sensory Play
I set the tray out on the kitchen table with the masher next to it and left them to it. My niece liked to squish the potato between her fingers. She couldn’t believe that it was potato without having a taste. A small note worth knowing: the lumps in the mash are a feature, not a flaw. They give the fingers and palms more textures to register, which is exactly what the activity is for.
The gel coloring rinses off skin within a wash or two. Beet juice can briefly stain light-colored clothes, so an apron or an old t-shirt is sensible. The whole activity works just as well outdoors on a tray or in a shallow tub, where the cleanup is easier and the colors look brighter in natural light.
The masher was the part they kept coming back to. Pushing, twisting and pressing it down worked on fine motor strength. Moving the masher up and down strengthened the hand and arm muscles needed for gross motor development. This kind of play sits in what occupational therapists call the oral-exploration window, the developmental stage where children still learn about new materials by mouthing them. Taste-safe sensory bins are designed for that window specifically.
After some time of mashing, the rainbow had turned into a playdough-like substance. They used it to sculpt, mold and shape. For older children who have outgrown the squish-and-mash phase, the same dough takes alphabet-shape cookie cutters cleanly, presses into number stamps, and slices into “cake portions” with a butter knife. The base activity carries from toddler through about age six.
The colors looked incredible.
As I had used a five pound bag of white potatoes I knew I had enough to make two sensory play activities. When the play finished, I scraped what was left into a sealed container and kept it in the fridge. Refrigerated, the colored potato is still good for a second play (and a second eat) two or three days later. The food coloring does not change the taste at all, and the texture is already mashed, so the leftover turns into hash browns or potato cakes the next morning. When I first wrote this post, I tipped the played-with potato into the trash. I no longer do.