To make goo without borax, combine cornstarch, flour and water in a pan over low heat. Add food coloring to make colorful goo. Stir the mixture thoroughly, then allow it to cool. This process takes less than 30 minutes.
- Mix water, cornstarch and food coloring
Pour 3/4 cup of water in a saucepan over low heat. Add 1 cup cornstarch and a few drops of food coloring. Stir the mixture with a wooden spoon, making sure that the cornstarch does not clump.
- Add the flour
As you stir the cornstarch mixture, add 1 1/2 cups of flour a tablespoon at a time. Sprinkle the flour into the cornstarch mixture to minimize clumping. Check the consistency of the goo. If the mixture becomes very thick, stop adding flour. If the goo is too thin, increase the amount of flour, adding a little at a time. Use the back of your spoon to make sure the flour is evenly distributed.
- Add more water
Slowly add 3/4 cup of water. Stir the mixture thoroughly, then turn off the heat. Let the pot of goo sit on the counter to come to room temperature. Stir it again with a wooden spoon when it is completely cool.