The large grains of rock salt are able to absorb the color from food coloring to create a colorful material for preschool activities. Handle the color ahead of time as it takes time to dry and gets messy. For each cup of rock salt, you'll need a few drops of food coloring and about 1 teaspoon of rubbing alcohol. The alcohol helps the color absorb and dry onto the rock salt. The amount of food coloring you add depends on the desired intensity of the color. Stir up the salt with the food coloring and alcohol until it is consistently colored. Spread out the colored rock salt on paper towels until the grains are dry. Use the colored rock salt for art projects like picture mosaics. Spread glue on paper and sprinkle it with the rock salt. Repeat with different colors around the paper. The rock salt also works as an alternative to colored sand. Layer the rock salt in a clear container with different colored layers.
Homemade salt dough offers an alternative to commercial play dough materials. The typical salt dough recipe calls for regular table salt with smaller granules. If you want to create greater texture in the dough, stir in rock salt when you make the dough. As the kids play with the mixture, they are able to feel the larger pieces in it for a tactile experience.
Rock salt is most often used to make homemade ice cream. Adding it to the ice helps the ice cream freeze faster. Preschoolers are able to make homemade ice cream in plastic bags with the help of rock salt. The ice cream ingredients go inside a pint-sized bag that is sealed tightly. For a basic vanilla recipe, use 1 tablespoon of sugar, 1/2 cup of half and half or milk and 1/4 to 1/2 teaspoon of vanilla extract. In a gallon-size bag, place ice cubes so it is about half full. Add 1/2 cup of rock salt to the ice. The smaller, sealed back them goes inside the gallon ice bag. Close the outer bag and let the kids shake it for five to 10 minutes to freeze the ice cream. The bag gets cold so wear mittens or gloves while making the ice cream.
Sensory tables are often found in preschool classrooms. If you don't have an actual sensory table, a shallow plastic tub works. Pour the rock salt into the table. The kids use scoops, sand shovels and other objects to play with the rock salt. You can also hide small toys in the rock salt and let the kids find them.