Food Preservation

Canning and Food Preservation

The ultimate way to eat local!

Whether you grow your own food or buy most of it from local farms, it’s worth taking the next steps in learning how to preserve it—so you can continue to eat local in the depths of winter, when the garden is frozen and the only things left at local farms are root vegetables.

The goal of food preservation is to prevent the growth of bacteria, fungi, or harmful microorganisms that promote decay and to prevent oxidation that can cause foods to become rancid. The main methods used to do this are canning, dehydrating, fermenting, and freezing.

Freezing is the method familiar to most people; freezers are common appliances in today’s households. But frozen goods have a limited shelf life before they deteriorate in appearance and taste, and preserving foods with that method requires a constant supply of electricity.

Dehydrating or drying, is a method of food preservation that dates back thousands of years. It can be done using heat from the sun, as the ancients did, or using an electric dehydrator. It may not result in a pleasing texture or flavor when used with some foods, but it is good for preserving herbs and for making meat jerky and other snack foods, such as dried fruits or fruit leathers. It’s a convenient way to preserve vegetables that might be used in soups. There are many different kinds of electric dehydrators on the market that can be purchased for as low as $35 to as much as $230.

Fermentation is a natural process that promotes the growth of microorganisms that help preserve certain foods, such as pickles, kimchi, yogurt, beer, and wine.

Canning is a relatively simple way to preserve foods, and in the end it can be more economical than freezing, because after the original investment in canning supplies and the expenditure of energy to process canned goods, there is no additional cost to maintain them in their preserved state. Once properly canned, foods will often last for years. And the benefits of home-canning vs. purchasing canned goods from the store? You know exactly what’s in those canning jars.

Canning can be used not only for fruits and vegetables, but also for meats, fish, and convenience foods (“meals in a jar”).

There are two canning methods: water-bath canning and pressure canning. Foods that have a high acid content—pickles, relishes, tomatoes, and many fruits, jams, and jellies—can be processed in a hot-water bath, which, combined with the acid in the food, will kill bacteria.

Main dish-type foods and low-acid fruits and vegetables can be canned only with the pressure-canning method, since this is the only method that will prevent the growth of bacteria in those foods.

Excellent resources for canning instruction include the Ball Blue Book of Preserving, and the Ball Complete Book of Home Preserving, by Judi Kingry and Lauren Devine. Ball is a well-known manufacturer of canning jars, and recipes and methods in these books have been tested at the company. An excellent online resource is, which features the USDA’s “Complete Guide to Home Canning.”

Water-bath canners can be purchased at most hardware and department stores for $30 to $60, depending on size. Pressure canners, also available at these stores, cost from $70 to $270, depending on size.

Canning jars can be purchased for $8 to $10 per dozen, and can be reused indefinitely, as long as they contain no chips or cracks. The canning lids that create the seal on the jar cannot be reused, unless they are designed specifically for that purpose, such as Tattler lids ( ). The screw tops that hold the lids in place can be reused as long as they aren’t dented or rusted.