In a medium saucepan, combine the white rice flour, cornstarch, table salt, and cream of tartar. Whisk to combine.
Stir water and vegetable oil into the dry ingredients. Stir to mix well.
Heat on stovetop over low-medium heat, stirring constantly using a silicone spatula, for about 5 minutes until the mixture starts to thicken and starts to gather around the spatula into a dough consistency. Remove from heat.
Transfer doh to a piece of parchment paper or a silicone baking mat and allow to cool a few minutes until it’s cool enough to handle with your hands.
Knead doh with hands until smooth.
Separate doh into however many different colors you’d like to make.
Place 1 drop of food coloring into each section of doh.
Using hands (I’d highly recommend latex gloves or a sealable food-safe bag for this step), knead the color into each play doh ball until the color is completely mixed in with no white streaks of doh remaining.
Play doh is now ready to play with!
Notes
Too much rice flour or cornstarch makes dry, crumbly dough.
A gluten-free flour blend changes the texture entirely, skip it.
Cream of tartar is what keeps this dough soft instead of stiff.
Making one color? Add the food coloring straight into the pot with the water.
Dough dried out? Knead in a small drop of vegetable oil.
Check every label, including cross-contamination warnings, before you start.
High salt content helps prevent mold, but check for smell or mold if a batch has been sealed for a few weeks before giving it back to the kids.