Food preservation is an easy method to increase the life span of some foods. By preserving your products you retain the appearance, texture, flavour, edibility and nutritive value of the foods. For example when you grow your own vegetables and you want to conserve them for winter or when you want to turn your raspberries or strawberries into delicious homemade jam. There are many different ways you can do so. Please see below for the most common ways to preserve your food.
Methods for Preserving Food
This is one of the oldest methods of food preservation. When you dry food, you expose the food to a temperature that’s high enough to remove the moisture but low enough that it doesn’t cook. It is important that you provide good air circulation. The additional advantage of drying is that it reduces the size and weight of the food product, therefore making it more portable. To dry herbs, simply tie them together and hang in a sunny spot away from any humidity. To dry fruits or vegetables, set them out on a clean surface and keep them in the sun for a few weeks (this only works well in dry, warm climates). A more modern method of drying is to use an electric dehydrating machine.
Micro-organisms require a certain temperature level to survive. Freezing foods lowers the temperature to levels that make the environment unsuitable for growth. In the summer time, you may want to freeze your berries so that you have them available for smoothies or baking later in the year. The best way to do this is to freeze fruits in batches (the same method would apply to vegetables). For instance, scatter fresh berries on a baking tray and put it in the freezer. After they have frozen solid, put them in a bag. This will avoid clumps of berries that are impossible to separate without thawing.
This method sometimes referred to as hot water canning, uses a large kettle of boiling water. Filled jars are submerged in the water and heated to an internal temperature of 100 degrees Celsius for a specific period of time. Use this method for processing high-acid foods, such as fruit, items made from fruit, pickles, pickled food, and tomatoes.
Pressure canning uses a large kettle that produces steam in a locked compartment. The filled jars in the kettle reach an internal temperature of 115 degrees Celsius under a specific pressure (stated in pounds) that’s measured with a dial gauge or weighted gauge on the pressure-canner cover. Use a pressure canner for processing vegetables and other low-acid foods, such as meat, poultry, and fish.
In this method food is stored in airtight containers that strips bacteria of the oxygen that helps it carry on with metabolism. Hence, the growth of these micro-organisms is arrested and food is preserved. Nuts are usually preserved by this method.
Sugaring is used to preserve fruits like apples, apricots and plums in sugary syrup that dehydrates the foods. The skin of certain fruits are cooked in sugar till they crystallize and then they are stored in a dry environment.
Salting is a sub category of the drying method. Salt is a natural food preservative that draws out moisture from the food as well as from the cells of the micro-organisms that may be present in it. Lack of moisture kills these organisms and hence prevents food spoilage. Salt is commonly used as a preservative in meat and fish products like beef jerky and dry salted cod.
Cucumber, beef, peppers and some vegetables may be preserved by pickling. You need two things for pickling: salt and acid. Pickling requires you soak your produce in brine with salt. When they have pickled for the desired amount of time you transfer them to a jar full of vinegar. At this point you can use the canning method to produce a vacuum seal, if you wish. A bonus of pickling is that it does not change the texture too much. The vegetables undergo a fermentation process, which also results in a vitamin boost. Pickled vegetables are known for having an increased level of vitamin B6.
Smoking is a complementary process to curing that improves flavour and appearance, and can also act as a drying agent. Smoked meats are less likely to turn rancid or grow mould than unsmoked meats.