Tapioca makes a great taste safe slime. Add some food dye for a colorful activity.
Add 1 part tapicoa to 7 part water.
Bring to boil on stove top, stirring frequently.
Tapioca is ready when it becomes transparent in color and like a fish egg consistency.
It does tend to hold its heat in the middle, so make sure you test prior to giving it to little ones to play with.