: While freeze-drying extends shelf life by lowering water activity to below 0.85, it does not kill bacteria ; microorganisms simply go dormant and can reactivate if moisture is added back. 3. Food Preservation & Storage

Beyond home use, freezing and freeze-drying are vital to several major industries:

: Unique among most substances, water expands when it freezes, which can lead to practical issues like frozen and burst water pipes . 2. Freeze-Drying Technology

: Removing any remaining unfrozen water molecules.

: This occurs when liquid molecules slow down enough that their natural attractions pull them into fixed, solid positions.

: Solidifying the water content rapidly to protect cellular structure. Primary Drying : Sublimation under a vacuum.

: For summer fruits like berries, lay them out on a tray to freeze individually before placing them in a bag to prevent them from sticking together. 4. Industry Applications