Pre-PAC for Culinary Arts Practice Exam

Freezer burn happens when air exposure causes moisture loss and fat oxidation on the surface of frozen foods. When air reaches the food in the freezer, water can migrate to the surface and even sublimate, leaving dry, discolored, leathery patches. Oxidation of fats at the exposed surface can also contribute off flavors. The best way to prevent this is to minimize contact with air by packaging foods tightly in airtight wraps, sealed bags, or vacuum-sealed containers, and to reduce any empty air space inside the package. Keeping the freezer at a steady, very cold temperature (about 0°F / -18°C) slows moisture loss and ice crystal formation, further reducing freezer burn. Avoid frequent thawing and refreezing, which can worsen moisture loss. Other factors like humidity or sunlight aren’t the primary causes of freezer burn.