Discover How Water’s Freezing Point Can be Lowered

How to Lower Water's Freezing Point?

Before or during a heavy snow or ice storm, you’ve likely seen trucks salting the road. Why is this? Salt causes ice to melt by lowering the temperature water freezes at. This is called the "freezing point."

The two most popular ingredients used in baking and cooking to alter the freezing point are salt and sugar.

What Is a Freezing Point?

The freezing point is the temperature when a liquid changes into a solid. To change a freezing point, a solute (such as salt or sugar) needs to dissolve into a solvent (the food’s liquid element). When the solute is evenly distributed, the change in the freezing point occurs.

What Are Salt and Sugar’s Role In Ice Cream?

When added to ice, salt has two main functions. First, it helps lower the freezing point and then acts like a small magnet to pull heat away from the ice cream. This results in the ice cream being able to melt and freeze.

Once all the ingredients in ice cream are mixed, they form a compound. This means that the ingredients are bound together and can only be separated by another chemical reaction.

Sugar plays a vital role by adding body to the ice cream and adding softness by lowering the freezing point. The amount of sugar added will determine the freezing point. For example, sorbets typically contain a higher amount of sugar than ice cream due to their high levels of acids (or the tang tasted in a raspberry or lemon sorbet).

As you may have noticed, on a hot summer day, a scoop of sorbet is often more refreshing than ice cream. This is because it stays frozen longer and is the freezing point at work!