Storing food properly can help prevent foodborne illnesses. Here are tips for safely storing food in your refrigerator and freezer.

Freezer Facts

Food that is properly handled and stored in the freezer at 0° F (-18° C) will remain safe. While freezing does not kill most bacteria, it does stop bacteria from growing. Though food will be safe indefinitely at 0° F, quality will decrease the longer the food is in the freezer. Tenderness, flavor, aroma, juiciness, and color can all be affected. Leftovers should be stored in tight containers. With commercially frozen foods, it's important to follow the cooking instructions on the package to assure safety.

There is little change in a food's protein value during freezing.

Freezer burn is a food-quality issue, not a food safety issue. It appears as grayish-brown leathery spots on frozen food. It can occur when food is not securely wrapped in air-tight packaging, and causes dry spots in foods.

Refrigerator/freezer thermometers may be purchased in the housewares section of department, appliance, culinary, and grocery stores. Place one in your refrigerator and one in your freezer, in the front in an easy-to-read location. Check the temperature regularly—at least once a week.

Refrigeration Tips

Bacteria can multiply rapidly in foods left to marinate at room temperature. Also, never reuse marinating liquid as a sauce unless you bring it to a rapid boil first.

This helps reduce the growth of Listeria bacteria and prevents drips from thawing meat that can allow bacteria from one food to spread to another. Clean the fridge out frequently.

Store refrigerated foods in covered containers or sealed storage bags, and check leftovers daily for spoilage. Store eggs in their carton in the refrigerator itself rather than on the door, where the temperature is warmer.

 A "use by" date means that the manufacturer recommends using the product by this date for the best flavor or quality. The date is not a food safety date. At some point after the use-by date, a product may change in taste, color, texture, or nutrient content, but, the product may be wholesome and safe long after that date. If you're not sure or if the food looks questionable, throw it out.

Infant formula and some baby foods are unique in that they must be used by the use-by date that appears on the package.

Storage Basics

Foods that require refrigeration should be put in the refrigerator as soon as you get them home. Stick to the "two-hour rule" for leaving items needing refrigeration out at room temperature. Never allow meat, poultry, seafood, eggs, or produce or other foods that require refrigeration to sit at room temperature for more than two hours—one hour if the air temperature is above 90° F. This also applies to items such as leftovers, "doggie bags," and take-out foods. Also, when putting food away, don't crowd the refrigerator or freezer so tightly that air can't circulate.

Keep the refrigerator temperature at or below 4° C. The freezer temperature should be -18° C. Check temperatures periodically. Appliance thermometers are the best way of knowing these temperatures and are generally inexpensive.

Many items other than meats, vegetables, and dairy products need to be kept cold. If you've neglected to properly refrigerate something, it's usually best to throw it out.

Refrigerated ready-to-eat foods such as luncheon meats should be used as soon as possible. The longer they're stored in the refrigerator, the more chance Listeria, a bacterium that causes foodborne illness, can grow, especially if the refrigerator temperature is above 40° F (4° C).

Anything that looks or smells suspicious should be thrown out. Mold is a sign of spoilage. It can grow even under refrigeration. Mold is not a major health threat, but it can make food unappetizing. The safest practice is to discard food that is moldy.

That's because foodborne illnesses are caused by pathogenic bacteria, which are different from the spoilage bacteria that make foods "go bad." Many pathogenic organisms are present in raw or undercooked meat, poultry, seafood, milk, and eggs; unclean water; and on fruits and vegetables. Keeping these foods properly chilled will slow the growth of bacteria.

https://www.fda.gov/consumers/consumer-updates/are-you-storing-food-safely