The salt causes the water to freeze at a lower temperature. When a solute, aka salt, is introduced to the system, the freezing point is lowered. This makes the water freeze at a lower temperature.
An atom hopefully this helps
Explanation:
Bring to the boil. Carefully place the can in the saucepan, ensuring there's enough water to completely cover the can at all times, topping up water frequently throughout the cooking process. Simmer, uncovered for 3 hours. Ensure the can is completely covered with water at all times during cooking
