The ideal freezer temperature for cold storage is commonly set at -18°C (0°F) for several reasons:
Food preservation: At -18°C, the low temperature inhibits the growth of most bacteria, yeasts, and molds that can cause food spoilage. While it doesn't completely destroy these microorganisms, it slows down their activity significantly, helping to keep food fresh for longer periods.
Enzyme activity: Most enzymes, which can cause changes in the texture, color, and flavor of food, become inactive or work at a much slower rate at -18°C. This helps preserve the quality of frozen food over time.
Freezer burn prevention: At -18°C, the formation of ice crystals is minimized. Freezer burn occurs when water molecules within the food sublimate and then redeposit on the surface, causing a loss of moisture and leading to a dried-out texture and off-flavors. Maintaining a proper temperature helps reduce the occurrence of freezer burn.
Energy efficiency: Setting the freezer at -18°C strikes a balance between food preservation and energy consumption. Lower temperatures require more energy to maintain, so -18°C is a practical compromise to ensure food safety without wasting excessive energy.
Food safety: The United States Food and Drug Administration (FDA) recommends storing frozen food at -18°C to prevent the growth of harmful bacteria and ensure the safety of the food you consume.
It's important to note that while -18°C is the recommended temperature for home freezers, commercial food storage facilities might have different temperature requirements based on the specific types of products they handle. In any case, maintaining a consistent and appropriate temperature is crucial for extending the shelf life and quality of frozen items.