CHAPTER 3: Freezing Foods

As mentioned in the introduction, preserving foods through freezing only became available in much of the world since the invention of refrigerators and freezers, about 75 years ago. However, many cultures have been freezing foods for millennia. People who lived in extremely cold climates, such as the Arctic Circle, dug storage places for the meat from hunting, or built a cache out of rocks. The meat was protected from predators, and when the people needed some food, they would chop a hunk off the frozen meat and cook it.

Other early cultures invented clever ways to keep food frozen during the summer months. The Chinese used ice cellars more than three thousand years ago. The ancient Incas, living in the Andes, learned how to freeze-dry food by removing the water content during the freezing process. In warmer climates, the Egyptians and Indians discovered that they could produce ice crystals by causing clay jars to evaporate water quickly. In addition, many cultures, including the Greeks and Romans, collected snow and ice from mountains during the winter months to line cellars that would keep food frozen during the summer.

Today, freezing is the safest, quickest, and easiest method to store food until you are ready to eat it. Freezing is also an economical method, because you can buy meat and produce when it is on sale or in season, and pack it away for later. Whether you have a large chest freezer, or a refrigerator/freezer combination, this chapter will explain how to pack and freeze foods properly. This chapter discusses how to keep frozen foods tasting as delicious as possible, and how long you should keep items in your freezer. It will also show you what to do when something goes wrong — such as handling a power outage or an unexpected thaw.

Freezing occurs when food is kept in a freezer at 0 degrees Fahrenheit (-18 degrees Celsius) for 24 hours or longer. Of course, the amount and texture of the food determines how quickly it will reach the optimal freezing state. Once the food is completely frozen, bacteria, yeasts, and molds that could cause food to spoil are rendered completely inactive. This means that though the bacteria is still present, it does not reproduce and cannot spoil the food. Some bacteria are destroyed by freezing, but many can begin to multiply once the food is thawed and begin to cause illness again. It is possible that sub-zero freezing can destroy trichina and other parasites, but it is still a good idea to rely on proper cooking to kill any parasites. Freezing also changes the enzymes present in food. This can be especially important in fruits and vegetables that may continue to ripen slightly while they are frozen. In these cases, a few extra steps, described in this chapter, are needed to stop the enzymatic process.

Although freezing meat produces food that tastes closest to fresh meat, all methods of preservation will change the flavor and texture of the food. Freezing can toughen some produce and soften other foods. In addition, food can take on a stale “freezer taste” or absorb odors from newly-frozen foods. To prevent this, defrost the refrigerator occasionally and wipe it down with cleaner and a wet rag. Frost-free freezers, which are standard appliances today, should not require ice removal but will still benefit from a periodic cleaning. Between cleanings, keep an open box of baking soda in the freezer to absorb odors and ensure foods have the best taste possible. Change the box every three to four months — you can pour it down your kitchen sink to get rid of odors there, as well.

Problems with freezing

You may notice two problems in your freezer — foods that take on a tough, dried-out texture and foods entirely covered with ice crystals. Neither of these conditions is dangerous to your health, but they will not add to your enjoyment of the food. Freezer burn happens when food is inadequately wrapped against the cold, and frozen air dries out the surface and damages the fibers of the food.

Ice crystals generally form when food is not packed properly or freezes too slowly. Later in this chapter, you will find tips on how to package food to protect it against freezer burn. Large ice crystals will form on food as it slowly releases moisture directly from the produce or meat. When you defrost these products, you end up with a great deal of water and a tough, dry portion of food. Ice crystals also form when a freezer has fluctuations in temperature that may cause slight thawing — again, releasing moisture from your food. An older or malfunctioning freezer will most likely cause temperature fluctuations, so it is smart to check your freezer now and then for a stable, cold environment. Food that has been frozen long past its lifetime will also be susceptible to ice crystals, but it is not harmful.

You will be most successful at freezing foods, and produce food with the best possible quality, if you use containers, bags, and wraps designed for the freezer. These are designed to be thick enough to keep moisture in and freezer odors out. Plastic wrap and sandwich bags are not thick enough, and often leave gaps that will cause freezer burn on your food. Foil is a good freezer wrap, but the disadvantage is that it is hard to tell what food is under the layer of foil. Plastic containers and casserole dishes designed to go from freezer to oven (or vice versa) are good choices as well, but some plastic containers can give your food a plastic taste — especially when new. Some people also use vacuum-seal machines that remove the air from a thick plastic bag, and then seal the open edge with heat.

Regardless of the storage container you use, always write the date and the contents of the package on the outside. Nothing is more frustrating than riffling through anonymous packages looking for that bag of eggplant from last month.

Freeze smarter

There are ways to freeze smarter so your food will taste better and your freezer will be more energy-efficient. Cold foods need much less energy to freeze than hot ones, so wait for hot foods to cool before freezing. If you live in a cold climate, you can save energy by placing the warm container outside and letting the weather cool it for you. Then place it in the freezer at a spot where there is plenty of space around the container so cold air can circulate around it. Once it is frozen solid, you can place it with the rest of the foods.

Remember to freeze food in small portions. The food will freeze faster and will taste fresher when it is thawed, and your freezer will have to produce less cold air to keep the food frozen. Freezing food in serving portions is also a smart idea; it can be hard to chip one chicken breast out of a package of six, or remove a few slices of bread from a frozen loaf. However, if you individually wrap meats, you can take out just what you need and save the rest.

When sealing the bags, make sure you remove as much air from the bag as you can. Any air remaining in the bag can cause freezer burn or allow condensing moisture to create ice crystals. If you use a container rather than a bag, make sure that the food fills the entire container. On the other hand, if freezing soups, sauces, or stews, leave some headspace at the top of the container to prevent the liquid, which expands as it freezes, from freezing to the lid — or popping the lid right off the container.

The following charts will help you remember the foods that freeze worst and best, how long to keep various foods in the freezer, and the best way to prepare them to be frozen.

Foods that do not freeze well:

• Buttermilk

• Eggs in the shell, whether cooked or raw

• Raw egg yolks

• Any products made of eggs, such as pudding, custard sauces, or pastries and cakes containing custard

• Sour cream

• Dips made with sour cream

• Whipped topping, including those in a frozen carton, an aerosol can, or prepared from a mix

• Whipped cream and half-and-half

• Yogurt

• Prepared salads: egg, chicken, ham, tuna, and macaroni salads

• Opened bottles of salad dressing

• Lettuce and other salad greens

• Radishes

• Green onions

• Cucumbers

• Opened cans of meat, poultry, fish, or seafood

Freezer storage times

The following chart shows various foods that freeze well, and the foods’ recommended storage times. These times are for quality purposes, rather than safety, because frozen food can stay safe forever.

If you take a food out of the freezer and are unsure about its quality after you defrost it, smell it to determine if it still good. If it smells odd, off, or rancid, discard it. If a food smells fine, but looks odd, it is still probably good enough to serve cooked in a stew or soup. You can cook suspect foods first and if they taste good after cooking, use them as ingredients.

Item	Months
Bacon and sausage	1 to 2
Casseroles	2 to 3
Egg whites or egg substitutes	12
Frozen dinners and entrees	3 to 4
Gravy, meat, or poultry	2 to 3
Ham, hotdogs, and lunchmeats	1 to 2
Meat, uncooked roasts	4 to 12
Meat, uncooked steaks or chops	4 to 12
Meat, uncooked ground	3 to 4
Meat, cooked	2 to 3
Poultry, uncooked whole	12
Poultry, uncooked parts	9
Poultry, uncooked giblets	3 to 4
Poultry, cooked	4
Soups and stews	2 to 3
Wild game, uncooked	8 to 12

Information courtesy of the USDA Food Safety and Inspection Service, public domain fact sheet at www.fsis.usda.gov/Fact_Sheets/Focus_On_Freezing.

Defrosting food

When you are ready to eat something that you froze, how you defrost it will have an impact on the food’s flavor, texture, and it could even have an impact on your health. The best way to thaw meat or a dairy product, for example, is to remove it from the freezer several days before it is to be cooked, place it in the refrigerator, and let it thaw slowly. A quick application of heat will start the multiplication process of any dangerous organisms. Never leave meat out at room temperature to thaw.

A quicker method is to keep the meat in a plastic bag and submerge it in cool water until it is thawed. This could take several hours depending on the size of the meat portion, but again, it will slow the growth of bacteria and parasites. Using the microwave to defrost your meat is also a good option, but watch the process so that the meat is not browned or overheated in some areas and still frozen in others. Any quick acceleration of heat will have an effect on the inactive microorganisms in the food.

Vegetables can be cooked from their frozen state — there is no need to thaw them. Any fruits or vegetables that will be used raw can be thawed in the refrigerator, where they will keep some firmness while defrosting. Fruits and vegetables do not pose as many health threats as defrosting meats. Many fruits and vegetables may lose liquid during the defrosting process, so you might want to drain them before using.

What to do when your freezer stops working

It could happen at any time — your freezer could fail, and then all of your investment in food and time could be lost. Your freezer may have mechanical problems, or someone could accidentally change the temperature, or a power failure could occur. A terrible thunderstorm could knock your power out for a week.

It is wise to know ahead of time what you should do to minimize your losses, and prevent illness due to spoiled food. At the moment of an emergency, you may have other things to worry about. So ahead of time, find local commercial or institutional freezers that may accept your food. Locate a dry ice supplier. If your area is subject to frequent power failures or you know there is a scheduled outage, set your freezer temperature between -10 degrees Fahrenheit and -20 degrees Fahrenheit, so that the food will be colder during the outage and less likely to thaw.

Once your freezer stops working, keep the door closed at all times. A freezer packed with foods that are frozen solid will continue to keep those foods frozen for about two days if the doors are kept shut. Putting blankets or other types of insulating objects around the freezer will also help keep foods cold, but be sure not to close off air vents, in case the freezer starts up again. Separate the meat from other foods, so that if the meat thaws, it will not drip juices onto other food.

Next, determine the cause of the failure. It could be as simple as an accidental disconnection, a tripped circuit breaker, a blown fuse, or an electrical shortage. In these cases, fix the problem as quickly as possible, and then check for any food that might be thawing. If the problem is the result of a power failure, contact the utility company to find out how long it will be before power is restored.

If the problem is not a simple one, or the result of a power failure, check the operating instructions for your freezer to see if there are any additional solutions before you call a technician. You might save yourself a service call.

Protect your food from thawing

Though a sealed freezer that is not operational may keep food frozen for a day or two, it is wise to plan ahead to protect your food from thawing. If you are in the middle of winter and temperatures will be well below zero for several days, you could pack your food in coolers and store them in a garage or shed, but do not store the cooler in sunlight. You might want to ask a friend or neighbor if you can store your food in his or her freezer — or perhaps distribute the food among several freezers. You could also check with a school, church, or social organization to see if they have freezer space for you to use temporarily. If there is a local freezing plant in your area, you may ask to store your food there.

When you move your food, be sure to protect it from thawing, as well. Place the packages into insulated coolers, or boxes that are lined with Styrofoam, thick layers of newspaper, or blankets. Once you take the food out of your freezer, get it to an operating freezer as soon as possible.

If you cannot find another freezer to store your food, you might be able to purchase dry ice and place it in your freezer to keep things cold. Check your phone book or the Internet for a local place that sells dry ice or carbonic gas. A full 20-cubic foot freezer will use a 50-pound cake of dry ice to keep the packages frozen for three to four days; a 10-cubic foot freezer will use a 25-pound cake. Note that if your freezer is half full, it will need more dry ice to keep it cold. When you buy dry ice, ask the company to cut it to the right size for you, and have them wrap each piece in plastic or other protective material. Dry ice is dangerous; you can lose layers of skin or give yourself frostbite by touching it with bare skin. Handle it quickly and always wear protective gloves to prevent the ice from burning your hands.

Place heavy cardboard or newspapers on top of your frozen food packages, put the dry ice on top of the cardboard, and close the freezer. Make sure the freezer is not opened again unless you must replace the dry ice, or the freezer is working again. The dry ice will gradually form a vapor that you can dispel by opening the door. The vapor is harmless and will dissipate quickly.

If you had to move your food to another freezer, this is the perfect time to unplug it, defrost, and clean it out. Use mild cleaners and wipe it down one last time with plain water so the freezer will not impart the taste to the foods that will be put back. While your freezer is not in use, leave the door open slightly to air it out. As a safety precaution for young children, be sure the door is propped so it cannot be closed.

What to do with thawed foods

Some thawed foods can be refrozen; others should be kept refrigerated and eaten quickly. Some foods must be discarded after a thaw. Note that re-freezing a food will break down its texture and taste. If you find you have too much edible thawed food to eat in the next few days, contact a church, shelter, or charitable organization to share your food before it spoils.

Here are some guidelines for food that is thawed:

Food	How to Handle
Baked goods	If the product is still solidly frozen, it can be returned to the freezer. Baked goods that are partially or completely thawed will have a poor texture and flavor if re-frozen. Instead, refrigerate the product and eat within the next few days.
Cheese	If the product is still solidly frozen, it can be returned to the freezer. If the cheese started to thaw, do not refreeze, because the flavor and texture will degrade. Refrigerate the cheese and use as soon as possible.
Fish	If the package is solidly frozen, it can be returned to the freezer. If the meat thawed but is still cold, check for bad smell or discoloration. If it looks and smells normal, cook and eat immediately. If the fish reached room temperature, it should be thrown away.
Frozen fruit juices	Juices that are still frozen can be returned to the freezer. Thawed juices should be refrigerated and used in the same timeframe as fresh juice.
Frozen prepared foods	If the package still has a layer of ice crystals, it can be re-frozen. Completely thawed foods should be cooked and eaten immediately. If the product reached room temperature, it should be thrown away.
Fruits	Check the package. If the food is mostly thawed but does not smell "off" or look spoiled or discolored, it can be refrozen; however, it may lose some taste and texture. Thawed fruits may be used in cooking or making jams, jellies, and preserves.
Ice cream	Discard thawed or partially thawed ice cream or frozen desserts.
Meat	Check the package. If the food is mostly thawed but does not smell "off" or look spoiled or discolored, it can be used within the next day or two. If the package is still very cold or mostly frozen, or has a layer of ice crystals, it can be re-frozen after packaging in new wrap. If the meat reached room temperature, it should be thrown away.
Poultry	If the package is still very cold or mostly frozen, or has a layer of ice crystals, it can be re-frozen after packaging in new wrap. If the meat thawed but is still cold, check for bad smell or discoloration. If it looks and smells normal, cook and eat immediately. Make sure any poultry juices from thawed meat do not touch any other food.
Smoked or cured meat	If the package is still frozen or very cold, it can be placed back in the freezer. Check for bad smell or discoloration of thawed meat; if it looks and smells normal, refrigerate and use within a day or two.
Vegetables	If the package is still very cold or mostly frozen, or has a layer of ice crystals, it can be re-frozen after packaging in new wrap. Thawed vegetables will lose most of the flavor and texture if you attempt to refreeze them; instead, refrigerate and cook within the next few days.

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