Food Preservation 101: Putting Canning In Perspective

I wrote Independence Days: A Guide to Sustainable Food Preservation and Storage because when it came time for me to take the next steps in eating locally and homegrown - to holding some of summer's bounty for the long winter, there wasn't any book that really covered what all I needed to know. After writing A Nation of Farmers about the "Why" of growing your own and eating locally, I ran into hundreds of people who had the same problem. They wanted to keep eating the same great food after the CSA boxes stopped coming or the farmer's market closed down, but they didn't know how.

One of the things I found as I became more expert at food preservation, and started to spend more time teaching and talking about it is that most of us have a mental image in our heads when we hear "preservation" mentioned. We think about canning, and about our grandmothers standing over a kettle in August, often for days on end. Indeed, when I did interviews they almost always began with someone's memory of putting by food - and always by canning.

Now canning is a great technique for certain foods, and if it is done right at home, it is both safe and yields a much better tasting product than any industrial scale food could ever offer. And how would it not - instead of a company buying a whole orchard's worth of peaches, all standardized to produce good canning quality but little flavor, shipped for several days after green picking, and then industrially processed, you can take peak-ripe food, often bought very cheaply at the height of the season or grown in your own garden, and process it to your own taste. I do a fair amount of canning, and I enjoy it - in part because I also don't spend weeks over a hot kettle.

But assuming that canning is the main form of food preservation available to us doesn't serve us all that well. People who have that mental image of grandma with a hot pressure canner (or worse, the image of an explolding pressure canner - old ones did explode sometimes, but they don't anymore) immediately leap to the conclusion that storing and preserving food is too much work. Plus, for those of low income there's the barrier of acquiring equipment - you do need to by lids new, and it takes time to build up a supply of used canning jars - and new ones are pricey.

Now all of these issues can be overcome - it is possible to shift the season of some canning. For example, I plant my main crop of cucumbers in late June or early July, rather than in May, like my neighbors. This means I'm not making pickles and running the stove in August, but doing it in late September, when the heat of my stove is wanted anyway. By using other food preservation techniques, and only canning when that's the best way for my family, I get more free time, and cooler. Laying out sweet corn in my solar dehydrator in August means that after a short bit of cutting, I go in and drink iced tea and allow the sun to do my work for me. Preserving food doesn't have to be hard - although there is some work involved, of course. But as long as we've got the assumption that it must be, we won't experiment.

Moreover, the other reason this bothers me is that canning is a fairly new technique, developed for Napoleon's army in the early 19th century, we've had canning for less than two centuries. On the other hand, human beings have been putting food by as long as there have been human beings - in cold or dry periods where crops do not grow, and for years of crop failure, drought or disaster, taking the excess of summer and autumn and putting it aside for times to come is one of the most basic and necessary of human activities. While canning is very useful for some things, if human beings couldn't store up food for dry or cold seasons and eat well without canning, we'd all pretty much be dead. I don't like to give canning pride of place simply because doing so crowds out the other ways we can preserve food, and our long and deep history of holding summer through the winter or the dry season.

Preserving food is simply too useful a technique to be abandoned because we assume that preservation means "canning." During high summer, at the produce peak, most farmers have bulk quantities of produce for *vastly* less money than retail prices. The same farmer that sells tomatoes for $2.50 lb may have a bushel for $20 (these are real prices, local to me, your own will vary by location and the season). A bushel of tomatoes will keep you in salsa and sun dried and fresh salad tomatoes for quite a while if you can come up with the $20, and will get you five times as many tomatoes as the same $20 would get you buying retail.

Potatoes in the fall run 70 cents a pound or more here - or 50lbs for $12. It doesn't take a math genius - and while many smaller families might quail at the thought of using up 50lbs of potatoes, it actually isn't that hard if you can use the simple technique of natural cold storage (commonly known as root cellaring, although you don't actually need a cellar, just any place that stays cool and doesn't freeze - an enclosed porch, spare bedroom closed off from the house, an old fridge or freezer on a porch, a garage, hay bales in a barn). You'll save a lot of money, trips to the store, and if you don't eat them all, you can plant them in the spring when they begin to sprout and make more potatoes.

Season extension, natural fermentation, cheesemaking, dehydrating, preserving with sugar, salt or alcohol, natural cool storage - all of these are great ways to store some food. And with some judicious canning, together they make a complex and wonderful diet for the seasons of our lives in which things do not grow. But no one technique is all.

Whenever I do interviews or teach classes, the first thing I do is try to very gently let people know that this isn't all about canning. Sometimes someone confesses that the thought of pressure canning makes them nervous. What I tell them is this - it is true that pressure canning can involve risk of botulism bacteria. However, so does eating industrially canned food - there's no magic in the industrial process that precludes this (in fact, there was an outbreak in commercially canned chile just a couple of years ago). If you are attentive and pressure can correctly, there is no reason to be afraid of it.

However, there's also no need to fetishize canning. Most of the other techniques we have used over the years to store food fell into disfavor, not because the techniques were valueless but because of the excitement generated by canning in the first half of the 20th century. Like baby formula and suburbia, canning was seen as modern, progressive, scientific and clean. And like baby formula and suburbia, things that might, in small quantities have been extremely useful were taken to ridiculous extremes. At the same time we were giving up the breast largely because of our sense that formula was progress, we were also giving up natural cold storage, lactofermentation and drying food.

Canning is a great addition to our repetoir - some things couldn't be the same without it. But it is only one of many tools. The trick is for us to reclaim what is worthwhile about our past (actually that may be a large chunk of our overarching project, not just our food project) and to put things like canning into perspective - as part, but not the whole of the basic human project of provisioning ourselves.


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Pressure canning on a woodburning stove takes some practice. Too much wood, pressure goes too high, close the damper, pressure falls, open damper throw more wood in, pressure goes too high...

It's like maintaining the ditch level: close the dump, ditch level rises, snow melts in the San Juans, river rises, ditch floods over the berm, quick! drive across town, close the dump, ditch level drops, people call complaining that they have no pressure, night comes, snowfields freeze back up, river drops, quick! open dump...

Or blood sugar for a diabetic, eating something sweet is like feeding the fire or closing the dump, blood sugar goes up, take a shot of insulin, close the damper, open the dump.
So it goes. Negative feedback.

When you chase pressure, water level, blood sugar, up & down like that, problems ensue. You blow too much liquid out of your jars. Floods & angry irrigators calling. Eventual kidney failure & retinopathy. So keep it smooth. Takes practice.

By darwinsdog (not verified) on 26 Apr 2010 #permalink

I mainly focus on canning because that's what I'm familiar with, but need to learn more about using my canned food on a regular basis, as well as other methods. I can't get my head around root cellaring because I live in Texas and it's hot and humid til past September or even later some years. I can't keep potatoes from sprouting or turning to mush and don't know if it's even possible in my climate.

I haven't done any canning in several years, though I have done and will do water-bath canning if I want to make homemade fruit butter. My DH has been doing lacto-fermentation recently (he seems to always have some ferment in progress). I have been drying herbs in ambient conditions for years and plan to start solar-drying tomatoes and other fruits this summer, now that I have a solar dryer, thanks to the DH. These are all easier and lower-energy than canning.

I really like root-cellaring because it is the least work of all methods, at least for me. We have the perfect place, a space under the stairs leading from the basement directly to the outside. This space stays near but above freezing from late November through early March. We didn't build shelves or in any other way modify the space; I store roots in 5 gallon plastic buckets. I don't wash the roots first as they store much longer with the dirt on them. In root cellaring books I have seen much made of the necessity for roots to be exposed to air to allow them to breathe, hence the use of open shelves and crates and the need to have some way to keep up humidity and keep out rodents in these cellars. However, the roots seem to get enough air in the 5 gallon buckets, and they stay humid on their own when storing them in buckets. My potatoes stored beautifully from late July (kept in 5 gallon buckets on the basement floor, then moved to the root cellar in November, then back to the basement floor in mid-March) until I planted the remainder in early April.

Sharon, how does one estimate the number of pounds of potatoes one person needs to overwinter? Assuming that the person is a regular potato eater. My mother used to do it, but I never asked her how much she would get... and now I am confused. Thanks!

My folks always did a lot of canning and freezing. We also stored potatoes in cool places. I'm not sure why, but we didn't store or eat a great variety of vegetables - mostly green beans, tomatoes and corn. I'm trying to introduce new veggies to my family. There are so many wonderful foods out there. Thanks for the encouragement to explore other food preservation methods as well. We don't plan to replace our air conditioner for a variety of reasons (cost, environmental, desire to spend time outside, etc.). I'd like to add other food preservation methods to save time, energy and a very warm house!
As always, thanks for what you write.

Kimchi was made as far back as 3,000 years ago.

I hate cabbage but love kimchi. Some clever Korean found how to turn nasty cabbage into tasty kimchi that would feed people through the cold winters, and through the summer until the next batches were ready to eat.

After some initial trepidation, I have mastered canning and this summer I would really like to explore solar dehydrating. Our climate is perfect for it - dry and between 85 - 110 all summer long.

Our climate is not so perfect cold storage. Like Marguerite above, I am wondering if it is even possible to store things like apples and potatoes in a climate like ours. We got a good harvest of potatoes this past fall, but I had to store them in the fridge, which I know is far from ideal. Our house is not air conditioned, we don't have a basement and the potatoes either sprouted and/or turned to mush when left out for a few days. There has to be a better way. Suggestions?

Just an FYI - you my grandma never needed to run the stove to pickle cucumbers - salt, dill, garlic, cherry leaves(make them crisp), water and cucumbers. that's it. will store for a year or 2 in a cool dark place - we used 3L glass jars with plastic lids. jars and lids may have been sterilized but i am not sure, i think a regular dishwasher would be fine.
the jars had to be rolled on their side every couple days for about a month.
best tasting pickles EVER.

hmm... - second guessing myself now - maybe the water was boiled - but the whole jar was never sterilized in the same way as fruit preserves thats for sure.

-- have to talk to my mom and write it down.


In Australia, water bath canning (traditionally called bottling) has a decent history, but pressure canning is basically unknown.

Interestingly the USDA precautions are almost never followed here - most people who make jams/relishes etc re-use commercial jars and lids,and use old school methods like inverting the jar to create a vacuum - no water bath at all.

I have converted to the 'purpose-designed canning jar and water bath' method (perhaps as a tribute to my US ancestry), but I'm in the minority.

Alas, where I live it's too humid for solar drying & root cellaring to be reliable methods - but fermentation works well!

I personally love dehydrating. People think of 'putting up food' as a lot of work - because like you say, they are envisioning days of work canning.

I can have six mushy apples cooked into sauce, run through the food mill and poured onto trays in the American Harvester in not much more time than it takes to clean up after dinner. If I have extra spinach in the garden, or a weary looking bit of celery in the fridge, they can be torn/cut into pieces and added to a few more trays, and the peel from the oranges can be grated for zest and put in yet one more tray. Plug the thing in overnight, and next day, you have dried fruit leather for snacks, spinach to sprinkle in soups or omelettes, orange zest for baking and celery bits for adding to stew and soup over the winter.

It's so quick and easy, I love it. I'd like a solar dehydrator, but at this point in time, I have power (some of which is provided by solar panels, actually), and this works great. I'm sure that the food I've rescued from compost by dehydrating has more than paid for the machine itself, I highly recommend them. :)

The main problem with canning is that the metal lids are lined with enamel that contains Bis-phenol A, which leaches into food. The only solution -- short of pressuring Kerr and Ball to provide BPA free lids -- is to go to all glass jars. Weck or an Italian brand. But then glass jars with glass lids have their own issues to manage.

I'd like to learn more about other ways to preserve foods.

Most people in warm climates can simply winter over their potatoes and other root crops right in the garden - unless you have a deep basement you may not be able to root cellar, but you also don't need to ;-).

NS, done properly your food should never come in contact with canning lids at all - at no stage during the canning process should that happen, and if your food is in contact, you probably won't get a good seal because of lack of headspace.


There is a wonderful book* that has many old preservation tricks in it. It's a reprint of an 1845 cookbook that was focused on practical every-day cooking, originally begun as a guide for the author's daughter as she set up her own household. Of course there is the disclaimer that the recipes are for historical curiosity only -- some techniques might not be safe -- but it's interesting to see what women used to do. A few things struck me:

1) They ate much more simply. A stewed chicken was a stewed chicken. At most, she suggested throwing in some celery "if available". Very few 12 ingredient recipes in this book!

2) Some of the preservation techniques were *incredibly* high in sugar! Any "preserve" recipe would have something like 3 lbs of sugar. "Cook until fruit is clear." I suspect not much nutrition in those recipes, but plenty of calories to get you through a cold winter day!

3) We have lost some very basic techniques to the convenience of on-demand food and electricity. Take eggs, for example. We can get them year round by using artificial light in the hen house, but even if we don't do that, we can keep eggs for quite a while in the refrigerator. In 1845, Elizabeth Lea suggested coating eggs in lard (shortening would do as well, I assume) and storing them in a cool place -- she put them on a high shelf away from the hearth -- for use in baking during the months when the hens were not laying. Good to know, if we ever need to get by without power or if fridge space is at a premium! (And would coating eggs in fat keep them good even longer in cold storage? Probably.)


By naturalmom (not verified) on 28 Apr 2010 #permalink

For those of us who live in humid climates, dehydrating can be done in automobiles...I would expect that there would be an issue with temps getting too high, but we could experiment and get it to work.

I use an electric one now, but plan to design and build a solar/auto one eventually.

As for the lids "poisoning" the food; I think between the headspace and the fact that the ring of plastic is only on the part of the lid that touches the rim of the jar, we will have much less bisphenol than commercial canned goods that have the entire can lined with the stuff.

I am one of those people who have negative memories of food preservation, because we literally did spend many many hours in our hot, humid kitchen, processing frozen veggies, preseves and jams, canned fruit and tomatoes, and let's not forget the pickles. My widowed mom somehow got roped into not only doing all that for our family of four, but also for my grandparent's household of 4 and my uncle's family of 4! I vowed to never ever do any of the above, but here I am...

I love Sharon's idea about planting some cucumbers later in the season to stagger the harvest and preservation. Great ideas we can come up with..

Also, the idea of drying odds and ends instead of thinking in terms of big batches...good one!



There's a very good book by Bill Mollison (the permaculture bloke) called, I think, Ferment and Human Nutrition. It's short on detail, but covers a wide range of low-tech preserving methods.

By David Irving (… (not verified) on 02 May 2010 #permalink