Cold Storage
Reducing the temperature at which food is stored slows the growth of food spoilage microorganisms and enzymatic reactions within food.
Many, but not all foods benefit from cold storage. (See Food Safety page for information about storing leftovers.)
Refrigeration
Refrigeration does not kill microorganisms that can spoil food, but storing food in a refrigerator set below 40 degrees Fahrenheit will slow the rate at which foodborne bacteria multiply. Inside the refrigerator's controlled conditions, food items can stay fresh and usable longer than at the ambient room temperature.
Refrigeration is the most common preservation tool in use.
- Keep refrigerator below 40° F
- Use a thermometer
- Keep foods from contaminating other foods – meats below fresh produce.
- Pay attention to package dating
- When in doubt, throw it out!
Freezing
Modern freezing is one of the easiest, longest lasting techniques we have. It is also the most convenient if care is taken in the freezing process.
Factors Affecting Quality of Frozen Food
- Enzymes - freezing slows enzymes, blanching can improve color and texture of certain foods
- Air - oxygen can cause flavor and color changes in improperly packaged food
- Microorganisms do not grow at freezing temperatures but are not destroyed
- Ice Crystals - the smaller the better, the quicker something freezes the smaller the crystals
- Freezer temperature - 0° or lower (use an in freezer thermometer)
- Evaporation of Moisture - proper packaging helps with evaporation of ice crystals that cause dried out, or freezer burned food
Freezing Pointers
- Freeze foods at 0°F or lower. To facilitate more rapid freezing, set the temperature control at -10°F or lower about 24 hours in advance.
- Freeze foods as soon as they are packed and sealed.
- Do not overload your freezer with unfrozen food. Add only the amount that will freeze within 24 hours, which is usually 2 to 3 pounds of food per cubic foot of storage space. Overloading slows down the freezing rate, and foods that freeze too slowly may lose quality.
- Place packages in contact with refrigerated surfaces in the coldest part of the freezer.
- Leave a little space between packages so air can circulate freely. Then, when the food is frozen, store the packages close together.
- Leave proper headspace to allow for expansion
Packaging for Freezing
- Moisture vapor resistant
- Durable and leak-proof
- Not become brittle and crack at low temperatures
- Resistant to oil, grease or water
- Protect foods from absorption of off flavors or odors
- Easy to seal
- Easy to mark
Other Important Things to Know
- Blanching helps improve the color and texture of frozen food
- IQF - Individual Quick Freezing: spread food on a tray and freeze, then repackage. Works well for fruits and some vegetables
Thawing
- Refrigerator Thawing - plan ahead as this is the safest way for meats
- Cold Water Thawing - faster but requires attention and can waste water
- Microwave Thawing - fine for certain foods, but uneven, can start cooking
- Cooking Without Thawing - move food straight from freezer to pot
Perishable foods should always be thawed in the refrigerator!