It’s harvest time! As another growing season comes to an end, many of us are looking for ways to preserve the year’s harvest. Preserving your own foods allows you to enjoy the taste of summer all throughout the year. But, before you run off to buy a box of mason jars or gallon size freezer bags, let’s take a look at the various techniques used for food preservation.
Space: The amount of space you have available to dedicate to the preserving process and/or space used for storage of preserved items should definitely impact your choice of preservation.
Cost: Naturally, the costs involved in preserving your food should be weighed against the cost of purchasing the food from a local market or vendor. In addition, there may be costs in using up storage space, purchasing specialized equipment etc. Of course, the health, environmental, and nutrient benefits that arise from preserving your own foods, should weigh heavily in the decision process, as well
Climate: The climate can aid or hinder different storage methods.
Available Equipment: Some preserving methods require specialized equipment that you may not have access to, or that you may be unwilling to use.
Nature of the Food: Be realistic about the ability of the food to be preserved. Some food may not tolerate any form of preserving and needs to be eaten fresh. Some foods can actually become toxic when preserved so you must do your research ahead of time.
Hygiene and Safety: Your ability to maintain a high level of hygiene and safety during the preservation of process is important.
Local Laws and Regulations: It is important to be aware of local laws and regulations regarding the preservation of foods, especially if you are planning to sell these items.
Food spoilage occurs from the growth of bacteria. Bacteria grows best under the following conditions: where it has a food source, when acid levels are ideal, when given time to grow, when temperatures are between 45-135 degrees, when there is oxygen, and when there is moisture. To slow the growth of bacteria, we restrict it from the ideal conditions needed to grow. When we slow the growth of bacteria, we extend the shelf life of our food. We call this food preservation. Each method of food preservation, attempts to restrict the bacteria from one or more of the ideal conditions it needs to grow and thrive. There are many methods of food preservation available.
Drying: Drying is an ancient technique of food preservation that is still used today. It is commonly used because it is inexpensive, as you rely only on the sun or an oven to eliminate moisture from the food. The dried items are compact and easy to store. The greatest disadvantage of drying is the loss of color and vitamins, and the change of flavor and texture.
Salting: Salt is another ancient method that reduces the moisture in food. When used as part of the drying process it increases the shelf life of items such as fish and meat and it enhances the flavor of dried items too. It is important to wash off the excess salt or salt water brine from the foods or they will become too salty in taste and the over-consumption of salt can be harmful to one’s health.
Canning or Bottling: Foods preserved by this method are sealed into a closed container, such as a glass jar, bottle, or can. Therefore, this process requires special canning equipment and a heat source to properly seal the container. Properly sealed containers deny bacteria the needed oxygen to grow. Items preserved this way can be stored for up to a year and maintain their flavor well. However, canning or bottling can be expensive after purchasing the special equipment needed and factoring in your fuel costs. There is also a high risk of severe food poisoning if this process is not done properly, especially in low acid foods such as vegetables and meat.
Sugaring: Preserving through the use of tree saps and/or sugar is commonplace in some parts of the world. The sap produced by some trees, such as the Maple, can be stored for long periods of time. The addition of sugar to some foods, like jams and jellies, can lengthen their shelf life.
Oil and Fat: Some items can be stored in fat or oil to increase shelf life. The fat or oil completely covers the food and denies bacteria the oxygen needed to grow.
Curing and Smoking: Smoking is a method used to dry meats, fish, cheese and nuts. The smoking process not only preserved the foods, but imparts a desirable flavor into the preserved foods. Curing requires the addition of curing agents known as nitrates and nitrites, followed by smoking to preserve the food. Although the taste of smoked and cured meats is desirable, be aware that nitrates and nitrites are carcinogenic.
Bin Storage: If you have access to a cool, dark place, such as a cellar or basement, it is possible to store foods for short periods of time just relying on the coolness of the room. The cool temperature will slow the growth of bacteria that causes foods to spoil. Shelf life can be further gained by storing items in bins of sand which restricts oxygen to bacteria on foods.
Fermenting and Pickling: High levels of acid will slow the growth of bacteria that causes foods to spoil. Fermenting and pickling are methods of preservation where foods are stored in a flavored acid. Foods like pickles, sauerkraut, soy bean curd, and eggs are examples of foods that have been pickled or fermented and can be kept for several months this way.
Refrigeration and Freezing: Most commonly used in the United States and other parts of the world, refrigeration and freezing slow the growth of bacteria by storing foods in cold or freezing temperatures. If electricity is available, this is the easiest method to store food. However, not all bacteria are killed through the freezing process so it is important to follow safe and sanitary food practices during and after thawing the item. Also, the quality of food can be diminished if not stored properly.
Many times a combination of methods are used to increase shelf life of foods. Whatever method is used, it is important to always label and date your preserved foods and follow all safety requirements to reduce the risk of bacterial contamination.