The process of lowering the temperature of a liquid or solid to its freezing point. At this point the item becomes solid. The temperature at which pure water freezes is 32º Fahrenheit or 0º Celsius. Impurities, minerals and miscellaneous substances in water (such as salt or alcohol) change the temperature or length of time required to freeze water. Thus, various liquid substances freeze at different temperatures based on their chemical composition. Solid items such as food also experience similar results, freezing at different lengths of time or temperatures based on their substance and chemical composition. Typically, items such as meat, poultry or fish will freeze in several hours. Keep in mind that the faster an item can freeze, the better it is for preserving the quality of the food item. Freezing a food and keeping it frozen will eliminate the opportunity for food borne illnesses to occur, since the pathogens that adversely affect food cannot grow. Freezing a food will not guarantee that it can be kept forever, since there are too many variables affecting the quality of the food prior and during freezing. Check foods for freezer burn. Be aware of the difference between the refrigerator freezer and a free-standing freezer. The refrigerator freezer is opened and closed often, affecting the amount of air leaking out, thus warming and refreezing contents. This leakage of air may cause food items to grow ice crystals as moisture forms from temperatures variations. Therefore, keep items in refrigerator freezers for a month or two while free-standing freezers can keep foods protected for up to 12 months.
When freezing foods, use materials that are safe for freezing and containing foods, such as plastic freezer containers, freezer paper, non-sticking freezer foil, or freezer bags. Materials that are not freezer safe will allow air to enter and affect the food, or in a reverse manner, allow odors to escape and affect surrounding foods. Generally, it is more important to be concerned with the way the food is wrapped rather than the container, but both are very important to keep the food as fresh as possible.
Foods that are to be placed together for freezing should be separated by a piece of freezer wrapping to keep them from sticking as they freeze. After wrapping or placing food in a freezer bag, force all of the air out of the package and seal it to keep it airtight thus reducing the chance for freezer burn. Refrain from using foil for any food that is acidic, such as citrus fruits or tomatoes, since acid reacts with foil and breaks down the material as it opens tiny pinholes allowing air to enter. When using plastic freezer containers, select a container size that is not too large for the food being stored. Excess space allows excess air to crystallize and adversely affect the stored food. To insure proper temperatures, check the freezer periodically with a refrigerator/freezer thermometer making sure temperatures for freezing are maintained at a safe level for food.