Supercool Ice Cream

Today in science we began learning about physical properties of matter, such as color, state of matter, (solid, liquid, or gas), boiling point, and freezing point. To explore some of these physical properties of matter, we made ice cream. Dan enjoyed following the recipe and mixing the ingredients in a zip-lock bag. We put the small zip-lock containing the cream, sugar, and vanilla inside of a larger zip-lock with ice and a splash of water. Dan really liked the measuring the temperature of the ice water with a digital thermometer. Then we added rock salt to the ice water, and measured the temperature again. Dan found that the temperature dropped quite a bit after adding the rock salt. This is because the salt ions interfere with the weak bonds between the water molecules, lowering the freezing point of the water and making it "supercooled." This supercooled solution is good for making ice cream, but Dan found that he preferred the creamier texture of store-bought ice cream to the "icier" texture of our homemade ice cream. Hmmm. More experimentation may be required... - Erica