Forgotten in the Fridge!

A birthday card cheerfully advises the recipient not to feel old because most people have things in the back of their refrigerators older than the card's recipient!

An article (author unknown) posted on several Web sites includes these tongue-in-cheek "guidelines" on "How to Tell When Your Food Is Spoiled":

• Eggs: "When something starts pecking its way out of the shell, the egg is probably past its prime."

• Meat: "If opening the refrigerator door causes stray animals from a three-block radius to congregate outside your house, the meat is spoiled."

• Chip Dip: "If you can take it of its container and bounce it on the floor, it has gone bad."

An elderly gentleman living by himself once said he used this standard on how long to keep food: "I toss a food when I don't know what it is anymore!"

While food safety is a prime concern, refrigerating and freezing food properly also is about TASTE. Proper refrigeration and freezing practices help assure both safety and quality. Here's how to do it ...

Purchasing refrigerated and frozen foods

Food safety and quality begin in the grocery store:

• Make the grocery store your last stop. Perishable foods should not be out of refrigeration more than two hours when the temperature is temperate, or one hour in warm weather when the temperature is above 90 F.

• Make refrigerated and frozen foods your last selections in the grocery store.

• Refrigerate meat and poultry immediately upon arriving home.

• Keep your refrigerator and freezer door closed as much as possible when putting away groceries so the food will chill rapidly.

• Purchase products before "sell-by" or "expiration" dates.

NOTE: Insulated thermal bags are helpful in keeping refrigerated and frozen food cold until you get home. These are becoming more widely available to consumers.

Recommended refrigerator/freezer temperatures

The following guidelines are based on information from the United States Department of Agriculture (USDA) and the United States Food and Drug Administration (FDA).

Bacteria grow most rapidly between 40 F and 140 F. There are two types of bacteria that affect foods:

• pathogenic bacteria that cause foodborne illness;

• spoilage bacteria that cause foods to develop unpleasant tastes, odors and textures.

Use a refrigerator/freezer thermometer

The numbers used to adjust the temperature on most home refrigerators only raise or lower the temperature. They do not match specific temperatures. A different setting may be needed during warmer months than colder months to maintain the same temperature. Using a refrigerator/freezer thermometer is the only way to assure your refrigerator and freezer are at the correct temperature.

Most refrigerator/freezer thermometers are either liquid-filled or bimetallic-coil thermometers. USDA describes these thermometers as follows.

Liquid-filled thermometers are the oldest types of thermometers used in home kitchens. As the temperature increases, the colored liquid (usually an alcohol solution) inside the thermometer expands and rises to indicate the temperature on a scale.

Bimetallic-coil thermometers contain a coil made of two different metals with different rates of expansion that are bonded together. The bimetal element is coiled, fixed at one end, and attached to a pointer stem at the other end. As the temperature increases, the pointer will be rotated by the coiled bimetal element to indicate the temperature.

Purchase refrigerator/freezer thermometers in the housewares section of department, appliance, culinary and grocery stores. Buy two! Place one in your refrigerator and one in your freezer. It may be the best $10 to $20 investment you ever make. Two more tips:

• Place the thermometer in the front of the refrigerator/freezer in an easy-to-read location.

• Check temperature regularly -- at least once a week.

NOTE: If the freezer compartment isn't a separate freezer compartment, but a compartment inside the refrigerator, it may be impossible to obtain a 0 F temperature. One sign of this will be soft ice cream. Plan to use food within a few weeks.

The safety and quality of food is affected by how it is handled BEFORE it is placed in the refrigerator.

• Refrigerate perishable foods so the TOTAL time they're at room temperature is less than two hours (or one hour in temperatures above 90 F). Perishable foods include:

  • meat, poultry, fish, eggs, tofu;
  • dairy products;
  • pasta, rice, cooked vegetables;

  • fresh, peeled and/or cut fruits and vegetables.

• It is OK to refrigerate foods while they're still warm. Just leave the container cover slightly open until the food has cooled. Refrigerate foods, no more than 2 inches deep, in shallow containers to speed cooling.

• Divide a large pot of food like a soup or stew into smaller portions and cool in shallow pans.
  

• As a general guideline, eat leftover foods within two days or freeze them. If you freeze foods immediately, cool them as described for refrigerated foods, before you freeze them.

Where foods are placed in the refrigerator has an effect on food safety and the amount of time foods may be stored for best taste. Some general guidelines include:

• Avoid storing perishable foods, such as eggs and milk, in the refrigerator door storage. With the opening and closing of the door, the temperature of foods stored in the door storage fluctuates more than in other areas of the refrigerator. Store eggs in their carton on a shelf.

• Place raw meat, poultry and seafood in a sealed container on a bottom shelf or in a meat drawer of the refrigerator to prevent their juices from dripping on and contaminating other foods.

• Avoid overfilling the refrigerator. Allow room for cool air to circulate and keep foods at the correct temperature.

• Store fruits in a separate refrigerator crisper drawer from vegetables. Fruits give off ethylene gas that can shorten the storage life of vegetables. Some vegetables give off odors that can be absorbed by fruits and affect their quality. Store fruits and vegetables unwashed to lengthen their storage life and maintain quality. Wash at the time of using.

Tips for tasty frozen foods

While appropriate storage times and temperatures are important for good-tasting frozen foods, the following factors also affect taste.

• Freezer packaging materials. Freezer packaging materials should be moisture-vapor resistant; durable and leakproof; resistant to oil, grease, water and the absorption of off-flavors and odors; and easy to seal and mark. The two types of packaging are:

  • Flexible wrapping materials. These include freezer paper, plastic freezer bags, plastic wrap designed for freezer use and extra heavy or heavy duty freezer aluminum foil.
    
    Check labels for specific use for freezing. For example, not all plastic bags are designed for freezer use. It is important to use materials intended for freezing as they're more likely to keep moisture out and less likely to tear in the freezer.
    
    For freezer paper, check directions for which side of the paper is placed next to the food. Unless directed otherwise, the plastic-coated side goes next to food. Secure freezer paper with freezer tape.

  • Rigid Containers. These include plastic, glass and ceramic containers labeled suitable for freezing. Some containers, such as milk and cottage cheese cartons, aren't moisture-vapor-resistant enough for freezing. When using glass and ceramic containers, use only those designated for freezing; otherwise, they may break in the freezer.
    
    CAUTION: Carefully read manufacturer's directions about safe handling when using glass or ceramic dishes labeled freezer/microwave/oven safe.

• Size of freezer container. The National Center for Home Food Preservation advises, "Do not freeze fruits and vegetables in containers with a capacity over one-half gallon. Foods in larger containers freeze too slowly to result in a satisfactory product." <www.uga.edu/nchfp/how/freeze/containers.html>.
  
  Freeze foods in quantities that will be used for a single meal unless food is "tray packed." Tray-packed food is frozen in a single layer on shallow trays or pans. When frozen, food is transferred to a freezer bag. The food remains in individual pieces and can be removed in the amounts needed. This method is frequently used for berries and chopped peppers.

• Head space. Food, especially fruits and vegetables high in water content, expand as they freeze. Most fruits and vegetables require some head space between the food and the container closure to allow for expansion. No head space is needed for loose-packing vegetables such as asparagus and broccoli and fruits and vegetables that were frozen individually on a tray before being packaged in a freezer container.

• Overwrapping meat and poultry packages. If freezing meat and poultry in the original shrink-film wrap longer than two weeks, overwrap these packages with airtight heavy-duty foil, plastic freezer wrap, or freezer paper, or place the package inside a plastic freezer bag.

• Type of meat. Generally, fatty meats and fish, cured meats, and shellfish will retain their quality for a shorter time than lean meats, fish, and poultry in a 0 F freezer. This is one reason freezer storage times are based on quality, rather than just safety alone. Food eaten in a timely manner simply tastes best.

• Freezing vegetables. Most vegetables need to be blanched before being frozen. Blanching involves partially cooking foods in boiling water and then rapidly chilling them to stop enzyme activity that hastens deterioration. Times vary for different vegetables -- consult a cookbook or website for more information.

• Temperature changes. Temperature fluctuations great enough to cause thawing and re-freezing of foods may lead to textural changes, such as softening and leakage. Using a refrigerator/freezer thermometer helps monitor your freezer unit for a constant temperature.

• Spices and seasonings. Clemsen University Cooperative Extension recommends: "When using seasonings and spices, season lightly before freezing, and add additional seasonings when reheating or serving. Pepper, cloves, garlic, celery seasonings, green pepper, imitation vanilla and some herbs tend to get stronger and bitter. Onion, paprika and curry change flavor during freezing. Salt loses flavor and has the tendency to increase rancidity of any item containing fat." <hgic.clemson.edu/factsheets/HGIC3060.htm>

• Speed of freezing. The faster food freezes, the better the quality. When foods freeze, the water in their cells freezes and expands. With rapid freezing, tiny ice crystals form. Slow freezing forms large ice crystals that break the cell walls of foods as they expand. This leads to moisture leakage and a change in texture as a food thaws.
  
  This is why rapidly frozen commercial foods may be higher in quality than those frozen more slowly at home.
  
  Expansion of water during freezing also is a reason why dry foods, such as crisp cookies, maintain their texture well when frozen and watery foods, such as cabbage and potatoes, do not.
  
  To speed the rate at which foods freeze, follow these tips:

  • Add only the amount that will freeze within 24 hours, usually 2 to 3 pounds of food per cubic foot of storage space.

  • Avoid stacking foods to be frozen. Spread them out throughout your freezer. Leave a little space between foods so air can circulate. After the food is frozen solid, move the packages close together.

• Freezer burn. Freezer burn, a condition in which the surface of food appears light-colored and dried out, occurs when moisture on the food's surface evaporates.

  Proper cooling, air removal, moisture-vapor-resistant packaging, a tight seal and an appropriate length of storage at 0 F or lower all help prevent freezer burn. Containers, such as freezer bags, should be pressed to remove excess air.
  

  While a food with freezer burn is safe to eat, the quality is lower. You can cut away freezer burn spots either before or after cooking. If a food is heavily freezer-burned, it may be desirable to discard it for quality reasons.

• Label foods. To avoid mystery meats and other foods of unknown age and possibly origin, label foods using freezer tape, gummed freezer labels or marking pens/crayons. Include:
  
  
  • name of food;
  • packaging date;
  • number of servings or amount;
  • additional helpful information, such as form of food (sliced, chopped, etc.), any special ingredients.
    

Refrigerator/freezer storage chart

Following is some food storage information adapted from materials provided by the USDA Food Safety and Inspection Service and the FDA Center for Food Safety and Applied Nutrition <http://www.foodsafety.gov/~fsg/f01chart.html>

Permission to reproduce: You may reproduce these materials for educational purposes but not for sales purposes. You're also welcome to link to "Food Reflections" from your website. Please credit: Food Reflections, University of Nebraska Cooperative Extension (lancaster.unl.edu/food/foodtalk.htm)

Use of commercial and trade names does not imply approval or constitute endorsement by the University of Nebraska Cooperative Extension. Nor is criticism implied of products not mentioned.
Return to Food Reflections Archives

University of Nebraska Cooperative Extension educational programs abide with the nondiscrimination policies of the University of Nebraska and the United States Department of Agriculture.