Soft ice cream stays soft because the freezing point of the water within the mixture is lowered, preventing it from becoming completely solid.
Here's a more detailed explanation:
- The Freezing Process: As the ice cream mixture cools, some of the water freezes and forms ice crystals.
- Concentration of Sugar: This freezing process increases the concentration of sugar (and other dissolved solids) in the remaining water.
- Freezing Point Depression: The higher concentration of sugar lowers the freezing point of the remaining water-sugar solution. This is similar to how salt lowers the freezing point of water on icy roads.
- Soft Texture: Because the freezing point is lowered, not all of the water freezes, resulting in a softer, more easily scoopable texture compared to regular ice cream. Essentially, it's a partially frozen mixture rather than a completely solid one.
In simpler terms, the sugar in the ice cream acts like antifreeze, preventing all the water from freezing solid and allowing for that delightful soft-serve consistency.
