A lot of us are trying to stretch our food budgets by growing our own or purchasing in bulk. Many are also joining CSAs (Community Supported Agriculture) programs, which provide them with produce (and sometimes other items) throughout the growing season. To take full advantage of local food sources, we need to find ways to store food after harvest. If you're new to food preserving, this post will give you a brief overview of the different techniques, and direct you to addition resources for home food preservation. Then you can decide which methods will work best for you.
How Can I Store Fruits and Vegetables at Home?
There are many ways to store produce for extended periods of time. The most common include:
This includes cool, dry storage, such as an unheated pantry or porch, and root cellaring, i.e., cool, damp storage. “Root cellars” may include actual root cellars, unheated basement space, crawl space, in ground “clamps” (holes or trenches for food storage) and other options. Cool storage basics, including storage requirements for many crops, can be found in the post “Root Cellars 101” and “Above Ground Root Cellars – Enjoy Your Local Produce Longer“.
I always include storage crops that can store without much processing, such as shell beans, pumpkins and squash and root vegetables. You can read more about my favorites in the post “Planning for Storage Crops“.
Food can be dried using a commercial dehydrator such as the Excalibur or American Harvest Dehydrator, or air dried in a solar dehydrator, on drying sheets or hang drying. Dried foods are great when storage space is tight, but dried foods lose more nutrients than root cellaring or canning. Dried foods should be stored in a cool, dry location in an airtight container for longest shelf life. The USDA recommends pasteurizing dried foods at 160F/71C for 30 minutes or freezing at 0F/-18C for 48 hours to kill insects and their eggs, but I haven't had any insect problems with food dried in my commercial dehydrator. Read “Getting Started with Home Food Drying“.
Canning is the heat processing of food in glass jars.
Water bath canning can be done with any large stockpot or kettle with a lid, as long as you have a way to keep the jars from sitting directly on the bottom of the pot and can cover your jars with at least two inches of water. Water bath canning is used to preserve high acids foods such as tomato sauce and pickles, and high sugar foods such as jams and jellies. If you can a pressure canner, you may use it for water bath canning by leaving the vent open.
Pressure canning must be done in a pressure canner, which processes foods using high temperature, high pressure steam. PRESSURE CANNING MUST BE USED FOR LOW ACID FOODS, such as beans, carrots, corn, soups, sauces, broth, etc.
Freezing foods typically produces flavors and textures most similar to fresh, and can be done without much specialized equipment. It is recommended that you blanch (briefly immerse in boiling water) most produce before freezing to stop enzyme action and insure best quality. I like to seal my frozen produce in vacuum seal bags to prevent ice crystal formation. I have found this to greatly improve the quality and storage duration for most crops.
Natural fermentation can be used to change low acid foods into high acid foods, giving them a longer shelf life to store “as is”, or allowing them to be canned in a water bath canner instead of a pressure canner. Through the use of salt, whey or specific starter cultures, food is fermented, improving its digestibility and nutrient content. It becomes what is referred to as a “live culture food”.
Because fermentation involves substances such as lactic acid and specific microbes, the flavor profile and texture of the food does change. Fermentation is responsible for treats such as chocolate, cheese, yogurt, and kombucha, as well as pantry staples like sauerkraut, kimchi, sourdough bread and vinegar.
Preserving in Salt and Sugar
More common before modern canning, freezing and dehydrating were available, packing foods in salt or sugar draws liquid out of the food, drying it, while the salt and sugar also interfere with microbe activity. These methods significantly impact food texture and flavor.
Immersion in alcohol
Booze is toxic to microbes (to us, too, if we consume enough of it). You can submerge small amounts of food completely in the hard liquor of your choice, and they will store almost indefinitely. Best for making flavor extracts or perhaps some highly flavored fruit. I've still got some raspberries in amaretto in the back of the fridge that I pull out for special occasions.
Microbes can't survive in a high acid environment, so vinegar can be used for food preservation without heating/canning. Think old-fashioned pickle barrel. I make at least one batch of vinegar pickles every season.
Immersion in Olive Oil
Very common is some parts of Europe, this is not one I recommend for the inexperienced home food preserver. Food is immersed in oil, locking out the air, to preserve it. The problem is that if the vegetables are low in acid, they present a serious botulism risk.
Which Food Preservation Method is the Best?
It really depends on what you're trying to store and your storage conditions. The Natural Canning Resource Book states:
“While some nutrients are lost during canning, recent research has shown that refrigerating fresh fruits and vegetables also results in nutrient losses, especially of fragile vitamins like vitamin C. for example, broccoli loses 50 percent of its vitamin C and Vitamin A (in the form of beta carotene) after five days of refrigeration, similar in scale to the loss of vitamin C during cooking and canning. This is because plant foods are alive and thus continue to metabolize nutrients during storage. It's safe to assume that root cellar storage causes the same magnitude of nutrient loss. Frozen food lose more nutrients than canned food after six months of storage. Dried food lose the most nutrients. With this in mind, canning is preferably done very soon after harvest, when nutrients are at their peak, thus preserving the most nutrients possible. “
In contrast, Mary Bell's Complete Dehydrator Cookbook states:
When you dry foods at home under gentle conditions, you produce a high quality product. Compared with canning and freezing, both of which involve extreme temperatures, food drying is the least damaging form of food preservation.
Who's more correct in their statements? I suspect both ladies may be correct, depending on the circumstances. In terms of taste and texture, I generally prefer frozen and canned products. Either way, properly ripened produce picked at perfect ripeness and processed quickly is nutritionally superior to most grocery store offerings.
Fermentation can add nutrition, but is generally limited to storage times of less than a year. Dried foods can last for years and take up very small amounts of space, but are best used in soups, stews or other recipes where they will benefit from long, slow cooking with plenty of liquid. Freezing is probably easiest for the beginner with minimal equipment, but requires freeze space, which can be limited. Canning can be used on a variety of foods, but does require some basic equipment. Canned goods may have a very long shelf life.
Recommended Food Storage Resources
and of course, here!
Concerns about Tattler Reusable Canning Lids
After reading rave reviews online about Tattler reusable canning lids, I took the plunge and ordered some with friends. My results were not as good as I had hoped. I noticed a significantly higher failure rate than standard canning lids, both during and after processing. The lids are also easily damaged if they are improperly removed from the jar (say by an eager little boy who is hungry for peaches).
The Natural Canning Resource Book details further concerns:
“Tattler lids are composed of polyoxymethlylen copolymer, an acetal copolymer. Copolymers are linked plastics which contain two or more ingredients. … (The author's father, a chemist) noted that the copolymer is made from a trimer of formaldehyde called trioxane and other compound variations. Formaldehyde is a highly-toxic substance long known to be carcinogenic. Some of the secondary additives are also potentially dangerous to human health and the environment.”
The Home Canning Resource Book also states that, “The National Center for Home Food Preservation has also documented higher levels of seal failure rates on Tattler lids than Jarden two piece lids.”
The book continues to give detailed evidence of uncombined formaldehyde in the lids. **Note – there has been some discussion about this on online forums since this post went live, noting that the temperatures involved in canning are not high enough to release the formaldehyde from its bonds in the copolymer. This is accurate.
When you have two ingredients going into a chemical reaction, A+ B=C. Unless the amounts of A and B equal exactly, down to the molecule, some of A or B will be left in the final product. Those “leftovers” are what could shed into your food with normal canning use – not the A and B that have already been converted to C. Risks should be minimal to the home canner, as the food within the jar is not in constant contact with the lid, but they do exist. I know many people are trying to reduce their use of plastic, or have immune systems that are already compromised, so I felt this was relevant.
Further, what happens to the workers who are exposed to the chemicals during the manufacture of these lids? Is it alright to expose them to formaldehyde, as long as it doesn't get into your food? If you have further questions, I suggest you contact the author directly at her website.
The Tattler lids should not be used with alcohol, strong acids, chlorine or strong sunlight, which will break down the plastic of the lids. I won't be ordering more of these lids.
Update: I decided to do a point by point Comparison of Jarden Metal Lids and Tattler Reusable Canning Lids.
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