Frozen food should be thawed in the refrigerator, the microwave or as part of the cooking process. If using the microwave, always complete the cooking process.
Perishable food, prepared food and leftovers should be out of the refrigerator no more than two hours. When these types of food are left at room temperature for more than two hours, the potential for bacterial growth increases. Divide the food and refrigerate within two hours.
Large quantities of food should be divided into smaller portions about 2 inches deep to speed cooling. Lids should be placed to allow steam to escape until completely cool, then cover.
Frozen food with freezer burn is safe to eat but a lower quality. Freezer burn occurs when moisture loss causes a grainy, brownish spot that is dry and tough. It may cause off flavors and poor texture, but will not cause illness.
Raw meats should always be stored on a plate or tray on the lowest shelf of the refrigerator. This prevents raw meat juices from contaminating other foods.
The only way to measure the temperature of food is by using a thermometer. Cold foods should be 40 degrees Fahrenheit and hot foods should be 140 degrees Fahrenheit or above.
Check for ice crystals. Check that the freezer temperature was kept at 0 degrees Fahrenheit or below. Each package should be inspected. Some foods can be refrozen.
The temperature range between 40 degrees and 140 degrees Fahrenheit is known as the temperature danger zone. Bacteria can grow in this temperature range.
Packing foods tightly in the refrigerator or freezer allows minimal air flow. This will increase the time to cool foods or keep the refrigerator too warm, and may cause bacterial growth. Food should not be tightly packed in a refrigerator or freezer. Separation allows cold air to circulate around the food.
Freezing only slows the growth of bacteria. After the food is thawed, the surviving bacteria can multiply and grow again.
From nola.com