Flash freezing

In physics and chemistry, flash freezing is a process by which an object is rapidly frozen by subjecting an object to cryogenic temperatures, or through direct contact with liquid nitrogen at −196 °C (−320.8 °F).

This process is closely related to classical nucleation theory. When water freezes slowly, crystals grow from fewer nucleation sites, resulting in fewer and larger ice crystals. This damages cell walls and causes cell dehydration. When water freezes quickly, as in flash freezing, there are more nucleation sites, and more, smaller crystals. This results in much less damage to cell walls, proportional to the rate of freezing. This is why flash freezing is good for food and tissue preservation.

Flash freezing is commonly applied in the food industry and is studied in atmospheric science.