Cooking Schools Guide: Preserving Food
All methods and types of food preservation have a common goal: to significantly retard or completely kill the bacteria that cause diseases. There are many methods used to achieve these results, including:
- refrigeration and freezing
- canning
- freeze-drying and dehydration
- salting and pickling
- fermentation
- carbonation
- irradiation
- cheese-making
- chemical use
The focus here will be on the processes of canning and pickling as two fun things you can do at home with produce you grow in your own garden. Canning refers to any kind of sealable container, not just specifically metal cans. In fact, most people who can at home use glass jars. To make canning and other kinds of food preservation easier, it’s best to have a few particular items on hand in your kitchen:
- food processor – you’ll want a good, sturdy processor that can handle a decent amount of food and won’t move around too much.
- food mill – this is a manual hand-crank that removes seeds and peels from fruits and vegetables, letting through all the flavor of the juice and pulp.
- food scale – a food scale offers an easier way to measure certain items, especially in large quantities. Look for one with a ‘tare’ feature, which will allow you to automatically subtract the weight of a bowl or any other container you’re using.
- vacuum sealer – the most efficient and effective way to remove air from bags. They’re useful for storing dried and cured foods, and for freezer-storage of either raw or cooked items.
While the above equipment is nice to have, the specialty supplies listed below are more fundamental to the processes of canning and preserving:
- tongs
- candy thermometer
- jar lifter (special tongs with rubber ends)
- canning funnel
- canning jars and (always new) lids
- water-bath and/or pressure canner (make sure you use the right one for the foods you are preserving)
Canning
The way in which canning preserves food is through heat. High enough temperatures (boiling) will kill the bacteria present in both the food and the can or jar. This is why it’s important to use jars that are designated as canning jars. They are made of tempered glass that won’t break at high temperatures. Once you reopen the container, bacteria will be able to get back in, even through the air in the environment, so leave them closed until you are ready to eat the food inside them.
There are two basic methods of canning. The first, water-bath canning, is recommended for foods high in acid (fruits, jellies, relishes, pickles). This is because yeast loves high-acidity foods and a water-bath canner is more effective at preventing yeast from fermenting. The second, pressure canning, is better for foods that are lower in acid (vegetables and meats). One of the most dangerous forms of bacteria is Botulism. This bacteria tends to stay away from high-acid and pickled foods, but loves the low-acidity environment of items like green beans. It is difficult to detect, being odorless and colorless, and the only sure way to kill it is to use pressure-canning. Boiling will not kill Botulism.
Never forget that you and your family and loved ones will be eating these food items later, so be careful to follow the process exactly. Stick to the cooking times and amounts, processing times and pressure level. Use the right ingredients. It’s particularly important to use canning or pickling salt when a canning recipe calls for it. Always use jars and lids that have been approved for canning and don’t reuse lids as their integrity may be compromised. Write the date on your finished cans and jars and don’t use them after more than a year has passed. It’s also a good idea to visually check your preserves on a regular basis and when you any signs of spoilage, throw it away without tasting it. The following are indications of spoilage in canned products:
- a broken seal
- color variation where there wasn’t before
- broken or mushy food
- food is not completely covered in liquid
- liquid is cloudy or has a lot of sediment
- moving air bubbles
More Resources for Canning
National Center for Food Preservation
Home Canning for first-timers and experienced canners
AllRecipes.com article on canning
Youtube video from ExpertVillage on how to sterilize jars
History and about Canning Jars
Pickling
Pickling is less labor-intensive and requires less specialized equipment than canning. It was once used commonly for all sorts of vegetables and even meats, but is now mainly used for cucumbers (to produce ‘pickles’) and with other select items like beets, sauerkraut (cabbage) and ginger. There are many different recipes for pickling and you can use a wide variety of different methods and vegetable or fruits, making pickled goods an excellent addition to the variety of your home pantry.
Ascetic acid, also called vinegar, and salt both have preserving qualities that are combined in pickling. Acid also has a second function in the pickling process, which is to inhibit the growth of bacteria. There are five basic methods of pickling:
- Fruit pickles – fruit, either whole or sliced, is simmered in a sweet and sour syrup
- Relishes – chopped or diced fruits or vegetables are cooked in a spicy vinegar combination
- Fermented pickles – these are soaked in a brine for 4 – 6 weeks, allowing lactic acid bacteria to grow but inhibiting other kinds. Sauerkraut is made in this way.
- Refrigerated pickles – marinated for a day to a week in salt and spiced brine in the refrigerator and then stored in the refrigerator for up to two months.
- Fresh-pack pickles – cured for several hours in vinegar or combined with a hot vinegar mixture.
If you have everything you need for canning, then you probably have everything you need for pickling as well, since many of the same items are involved in both processes.
More Resources for Pickling
National Center for Food Preservation
AllRecipes.com pickle recipes
Youtube video from Howcast on how to pickle vegetables
Pickling Timeline from the New York Food Museum
2010 Herb of the Year: All About Dill
Additional Resources for Recipes and Other Types of Food Preservation
Recipes for preserving summer fruits and vegetables
Recipes for preserving fall and winter crops
Homestead Anywhere for freezing and dehydrating
All About Curing including historical background
