Why does a hot glass baking dish crack in the freezer?

A hot glass baking dish can crack in the freezer due to thermal shock. When a hot object is suddenly placed in a very cold environment, the difference in temperature creates stress on the material, causing it to break. Glass has a low coefficient of thermal expansion, which means that it does not expand very much when heated. This makes it more susceptible to thermal shock than materials that expand more readily.

When the hot glass baking dish is placed in the freezer, the cold air causes the outer surface of the dish to cool and contract rapidly. However, the inner surface of the dish is still hot and expanded. This creates a stress gradient within the glass, with the outer surface pulling inwards and the inner surface pushing outwards. If the stress is too great, the glass will break.

To avoid cracking a glass baking dish, it is important to allow it to cool gradually before placing it in the freezer. This can be done by setting the dish on a trivet or cooling rack to allow the heat to dissipate. Alternatively, you can place the hot dish in a warm oven and let it cool down gradually with the oven.