What You Need to Know
Freeze-drying, also known as lyophilization, involves freezing food to a temperature of -30°C and then reducing the surrounding pressure to allow the frozen water to sublimate (change directly from a solid to a gas) without going through the liquid phase.
Steps
- 1.
Chuño (Andean): Traditional freeze-drying of potatoes at high altitude
- 2.
Astronaut ice cream (NASA): Creates shelf-stable dairy product for space missions
- 3.
Instant miso soup (Japan): Preserves delicate umami compounds in fermented paste
The Science
Primary Reaction
sublimation