A good friend of mine brought me a gift jar of pickled onions, green beans and garlic a few weeks ago. Everything was grown in her garden and it was so thoughtful of her to elongate the life of her carefully grown crops and share both the food and the spirit of preservation with me. My parents in-laws are just as generous in sharing the many products of their bountiful harvests. They live on an acreage in NW Iowa and have five very productive gardens, an apple and pear orchard, and countless fruit and nut trees and bushes. They are always busy canning, drying, pickling, cooking... celebrating food! They live close to the land, eat seasonally, preserve excesses and there is very little food waste in their home. It is inspiring!
WHY FOOD PRESERVATION?
Preserving foods allows us to enjoy them long after they would have otherwise spoiled. It slows down the inevitable food decay process. We usually don't even think about putting food in the refrigerator but there are various methods beyond refrigeration to explore to help us prolong the enjoyment of our favorite foods. In the process, we can significantly reduce food waste and possibly even save money. Preserving foods can also bring a whole new dimension to their experience – cabbage can be transformed into sauerkraut, cucumbers into pickles, milk into yogurt and meat into jerky! It's a whole new world for these foods! But in doing so, do we sacrifice the taste or nutritional content of fresh foods?
FOOD PRESERVATION METHODS
Freezing
This is a simple way and easily accessible way to preserve foods. Cold temperatures slow the oxidation process and prevent the growth of microorganisms that cause food spoilage. The materials needed are minimal as well. According to the National Center of Home Food Preservation, packaging materials should be moisture-vapor resistant, durable and able to maintain their structural integrity in low temperatures, that is, not become brittle or crack. Good options include rigid containers made of “aluminum, glass, plastic, tin or heavily waxed cardboard; bags and sheets of moisture-vapor resistant wraps; and laminated papers made specially for freezing.” Vegetables can be blanched (boiled or steamed for a short period of time) prior to freezing to better preserve their flavor, color and texture. It also helps to maintain vegetable vitamin content. When packaged properly, foods can last up to several months in the freezer and below 0 degrees F.
Drying
This form of preservation is very familiar to me since I grew up in tropical West Africa. We dried everything! We simply put vegetables and meats out in the sun for several days until they were completely dry. The heat and exposure to dry air removes the moisture from foods and therefore prevents the growth of bacteria. We would then store the food in a cool, dark place and use them for several months either in the dry form or reconstituted with water. We did not have the luxury of electrical food dehydrators but they can come in very handy especially because of how quickly they can dry foods, albeit in limited quantities. This is a great recipe for homemade beef jerky without the typical and sometimes troublesome additives of MSG and nitrites.
Canning
Canning involves heating food to a specific temperature in a home-canning jar with a two-piece vacuum seal lid. This destroys harmful microorganisms and creates a vacuum seal that prevents microbes from entering the jar. The two types of canning are via water-bath and steam-pressure processes.
Higher acid foods like fruits, juices, and tomatoes are canned using the water-bath process. The food is placed in a canning jar, capped with a two-piece lid and placed in a water-bath canner filled with water. Lower acid foods are canned using the steam-pressure method. These include vegetables, meats, and seafood. The temperature and duration of heating is specific to the food being preserved. The jars are left to cool completely to room temperature to ensure that lids are properly vacuum sealed. This method destroys molds, yeasts and some bacteria.
Canning does require jars and lids, a water-bath canner or steam pressure canner. If done properly, home-canned foods can be stored for long periods of time in a cool, dry, dark place. Some can also be frozen afterward for an even longer storage time.
Fermentation
Fermentation is the process of converting carbohydrates (sugar) into acid, gases and/or alcohol. The microbes involved are great sources of probiotics.Fermenting foods increases their nutrient content by increasing levels of minerals, amino acids and vitamins like B's and C . There are many foods that can be fermented at home including beverages (beer, wine, kombucha), vinegar, breads, yogurt and sauerkraut.
Pickling
Pickling is a process by which foods are preserved by anaerobic fermentation in salt brine or vinegar. All that is required is the chosen food, jars and lids. In brine pickling, the food itself produces the preserving agent through the production of lactic acid. It produces foods like pickled cucumbers, sauerkraut and kimchi. Foods that are pickled vinegar are not sources of probiotics since there is no fermentation involved. The acidic properties of the vinegar can, however, aid digestion of those who might have lower stomach acid in general. Speaking of the stomach, studies have shown that there is a high correlation between stomach cancer and a diet high in smoked, salted and pickled foods so moderation is key when choosing to enjoy these foods.
SAFETY PRECAUTIONS
Be sure that the foods you choose to process/preserve are fresh and properly cleaned before preserving them.
Follow the processing instructions very closely to ensure the quality of the finished product and prevent the growth of harmful microorganisms that can cause food spoilage and potential illness - the most concerning of which is botulism. This is a rare paralytic disease caused by a nerve toxin produced by clostridium botulinum in improperly canned foods. The symptoms of double vision, droopy eyelids, slurred speech, difficulty swallowing, dry mouth and muscle weakness can begin as early as 6 hours after consumption of contaminated food or as late as 10 days.
Ensure that all equipment and processing surfaces are properly cleaned and sterilized to prevent microorganism contamination.
NUTRIENT CONTENT
Fresh foods begin to lose their nutrient content from the moment they are harvested. It is always best to consume them as close to harvesting as possible but if we are not growing/raising our foods, they will continue to slowly lose nutrients as they are transported to grocery stores and patiently await being purchased and hopefully, eventually consumed. The good news is, provided that the foods are free of added salt and sugar, their nutrient value is often as good if not better than fresh produce depending on how soon after harvesting they are processed. Canned food can lose small amounts water soluble nutrients like vitamins C and B but these are often found in the liquid they are packed in. Generally, canned foods are comparable in vitamin content as well as dietary fiber and proteins. So go ahead - can, dry, pickle and freeze to your heart's content!
Still need some motivation to try home food preservation? Allow me to introduce you to the wonderful world of Pinterest! Feast your eyes on these beautiful finished products and how-to guides. You're welcome.
Resources:
References:
www.alive.com - A Tale of Two Pickles
www.mayoclinic.org - Stomach Cancer
www.cdc.gov - Botulism
nutrican.fshn.uiuc.edu – Nutrition Study Summary Findings
blogs.chihealth.com – Food preservation
Dr. Adeola Mead, ND is the Natural Choice Network's Healthy Living Content Coordinator. She is a Bastyr University graduate and Seattle based naturopathic physician. Dr. Mead is passionate about using natural medicine education as a powerful healing tool for both individuals and communities.