Freeze food without freezer burn
Ice crystals tear food cells as they grow. At -18°C (0°F) or colder, thin portions freeze fast and the crystals stay small, so more texture survives. Slow freezing grows big crystals that turn berries and bread mushy.
Remove air to prevent freezer burn
Freezer burn happens when water slowly leaves the food surface and turns to frost inside the package. Press out the air and wrap tightly, or use a vacuum bag. Food stays safe at -18°C (0°F), but quality fades after about 3 to 6 months.
Test yourself
Questions from the interactive lesson, with the answer and the why.
How do you freeze fresh berries so they don't clump?
Spread them on a tray first, then bag them. Each berry freezes separately and stays loose.
True or false: Freezer burn is food that has gone bad.
False. Freezer burn is surface drying caused by air, and the food is safe to eat but dull and dry.
What went wrong? You freeze warm soup in a loosely closed tub. Two months later it's covered in frost.
Warm food and trapped air create frost and freezer burn. Cool the soup first and pack it with no air space.
Fill the blank: Freezing food in thin, flat bags helps it freeze fast and thaw ___.
Freezing food in thin, flat bags helps it freeze fast and thaw quickly. Thin pieces change temperature much faster.
Which food freezes worst?
Lettuce and other watery raw greens. Their cells burst when the water freezes, so they go limp.