Back in the 1800’s, an icehouse – filled completely with natural ice from lakes that are carved into blocks – served as the means for freezing food. With the modern food-freezing method, we tend to value too lightly the luxury of foods; this in spite of our being able to enjoy foods (even those that are not in season), the whole year round. But more than the convenience that frozen foods provide, freezing likewise affords us the best possible way of preserving the nutritive substances in fresh food.
Freezing foods (or buying frozen foods) requires that you observe certain safety measures. For example, have you noticed that foods which don’t readily freeze, when thawed and then refrozen, develop large ice crystals? These crystals destroy the food’s cell walls, making the food excessively tender. Water-soluble vitamins, especially vitamin C, are also absorbed by these ice crystals, which go down the drain when the food is defrosted. A good way of preventing ice crystals from forming is to maintain the temperature in your freezer at zero degree Fahrenheit (negative eighteen degrees Celsius).
Always keep your freezer full as this keeps food colder than a nearly-empty one does. But leave some space around the items in your freezer to hasten the freezing process. This way, you can stack the foods once they freeze. The best containers to place foods in when freezing are freezer-safe bags or wraps, heavy-duty aluminum foil, and those made of glass or plastic.
If you choose to use freezer-safe bags or plastic containers, make sure that you get rid of as much air as possible before sealing them. This will keep air away from food and prevent freezer burn (depletion of food nutrients and liquids caused by exposure to air). A highly-suggested method is to secure foods in plastic wrap, then wrap tightly in foil.
Certain vegetables may require brief steaming or boiling, and then cooling quickly in an ice bath, before being placed in the freezer. This technique slows down enzyme activity that can cause the loss of nutrients in vegetables. Fruits, on the other hand, may have to be soaked in citric acid or lemon juice before freezing to ensure that their nutrients are retained.
Avoid buying packed frozen foods which have ice crystals on them, the reasons being those mentioned earlier in this article. Frozen foods should be bought at the supermarket last and unpacked at home first. Because supermarket wraps are usually permeable to fluids, it is suggested that you add another layer of wrap when freezing meats in their original supermarket wrap.
As important as strictly observing the safety measures when freezing food is making sure that defrosting them is done safely. In defrosting food, one rule that must not be ignored is to “never defrost food on the counter.” Since the inside of food can remain frozen while the outside gets warm, bacteria can grow as the frozen food gets thawed on the counter.
A method, which is considered the safest, is defrosting food right inside the refrigerator. However, this method defrosts food rather slowly, taking about a full day for every five pounds (about two kilograms) of food to thaw. Once food is defrosted this way, it can be refrozen.
A faster way of defrosting food is by means of a method known as cold-water bath. In this method, frozen food is sealed in a leakproof bag, and then immersed in cold water; water is changed every half an hour. Food defrosted this way should be cooked before refreezing.
The fastest way for defrosting food is through the use of microwave. In this method, the directions on the package or the microwave are simply followed; the food should then be cooked at once. As in the cold-water bath method, food defrosted by means of the microwave method should be cooked before being placed back in the freezer.
Another rule you must not fail to heed is that when frozen food begins to thaw as a result of power failure, cook it immediately. Food that has been above four degrees Celsius (forty degrees Fahrenheit) for more than a couple of hours should be thrown out.