You can take the boy out of the farm but you can't take the farm out of the boy

May 8, 2008 7:36 AM

Best practices on home canning?

So much to the amusement of Mrs Mutant, I've laid in about a dozen tomatoe plants, five Broad Bean vines, ten Bell Pepper plants and five Cucumber plants. I'm also planning to plant some potatoes and onions.

As we live in London and our flat is located on land with a history of industrial use (and I'm too cheap to pay for an evaluation of the earth in our garden) all planting is being done in 47cm pots. From the bottom we've got rocks, sticks, earth, compost, with the seeds in the compost.

I should be able to start harvesting in about two months, but wanted to get some ideas about best practices for home canning. I'm ashamed to admit that back on The Farm my grandma canned frequently but, as I was more interested in cartoons, I didn't absorb much more than cutting, boiling and bottling.

From reading I realise that cleanliness is key, and further, that tomatoes appear to be the safest (due to acidity). If things go well, we should have a large quantity of those to be canned.

Can we combine the tomatoes with other vegetables? I was hoping that perhaps the acidity would help with other vegetables that might be troublesome on their own.

What combinations, if any, can we make from what we're planning to plant? Or should we focus on canning vegetables individually?

Finally, what about fruit? We can get very cheap deals on seasonal fruit from street markets but I've read the sugar makes this a relatively riskier undertaking. Does anyone have a view on canning fruit?

Many thanks!

posted by Mutant to food & drink (17 answers total)

You can can non-acidic stuff if you get a pressure canner.

This site indicates that anything above a pH of 4.6 should be pressure canned. So you can always try to make whatever you want and test the pH. Alternately, buy a pressure canner and preserve those veggies all you want.
posted by GuyZero at 7:51 AM on May 8, 2008

The USDA guide to home canning is available online. If you follow these instructions, you are sure to be safe; of course, being from the USDA, they also err on the side of safety, but until you're an old hand that's probably just what you need.
posted by redfoxtail at 7:52 AM on May 8, 2008 [2 favorites]

People have canned fruit for eons, I wouldn't worry too much. Really, anything you see at the supermarkets in cans or jars can be canned at home.

I would can the things individually as much as possible- keeps your options open.

And yes, cleanliness is key. Also following the directions as far as making sure you have the acidity right. Very bad things can grow in no-air environments.
posted by gjc at 7:52 AM on May 8, 2008

My advice is to freeze as much as you can instead of canning. Tomatoes (whole, roasted, sauced, diced, etc...) work particularly well for this, as well as corn. I find freezing to be a whole lot less work, less risk and requires less equipment. Regardless of your preference, the National Center for Home Food Preservation website is a great resource, because it lists just about every food you can imagine and then offers both canning, freezing, and other preservation techniques that do or do not work for any particular fruit or vegetable. This is one place where I think my tax dollars went to good use.
posted by webhund at 7:56 AM on May 8, 2008 [5 favorites]

The Ball Blue Book of Preserving is pretty much the bible of canning.
posted by SuperSquirrel at 8:17 AM on May 8, 2008

I second the link for the USDA home canning -- especially the section on how much acid different foods need, how much processing time you need, and the like.

Conceptually, I think mixing different foods is possible, but speaking as another home-canning novice, I wouldn't do it without having a specific recipe in front of me -- the amounts of acid and the processing time are SO important, and different foods need different levels of acid, and trying to figure out and calculate what would be necessary if you combined foods is something that intimidates me. Single-vegetable canning may be best for a first attempt, unless you're following a recipe.

It is definitely possible to can fruit, as well -- I've had great luck with peaches in particular. Peeling them sometimes was fussy (I used the same method as peeling tomatoes -- and one batch, it didn't quite work as well), but they've stayed preserved. I did have to use a lemon-sugar syrup to can them in. As for other fruits -- the USDA canning guide can advise you on what you'd need to do, or whether it's possible; not every fruit cans well, and freezing may be better for certain fruits. Jam's also a good option for seasonal fruit.

But to sum up: while my family is a supplier for Ocean Spray, the only "farming experience" I had was the annual school field trip to the local agriculture college to pet the baby pigs when I was a kid, and yet I was able to can 20 pints of tomatoes, 3 pints of peaches, 4 pints of blueberry sauce, and scores of jam and preserves in my tiny kitchen in Brooklyn using only a stock pot water bath and an UTTERLY ANAL fixation on following prewritten instructions.
posted by EmpressCallipygos at 8:27 AM on May 8, 2008

Really, anything you see at the supermarkets in cans or jars can be canned at home.

Uh, sort of. Much of that stuff is pressure canned. So plain broad beans cannot be canned in a water bath alone.

There are two home canning ways to make a water bath work and avoid botulism: acid and sugar.

I was able to can 20 pints of tomatoes: acid
3 pints of peaches: in sugar syrup
4 pints of blueberry sauce: sugar
and scores of jam: sugar

So as long as you follow recipes and make things acidic (tomatoes, pickles) or sweet (jams, fruit in syrup) a water bath is indeed fine. If you want to can the broad beans straight up you'll need a pressure canner.

If this is your first go-around with canning please follow fixed recipes that have been tested, like the Ball book or Bernardin or whatever. Because botulism is deadly and very difficult to detect.
posted by GuyZero at 8:40 AM on May 8, 2008

I use Le Parfait jars for canning / preserving / pickling which are not even USDA approved. I take a much more French attitude to the whole process, being careful but not utterly meticulous about sterility. This eGullet guide is a good basic primer for the sort of stuff you can easily handle at home without specialist kit.
posted by roofus at 9:25 AM on May 8, 2008

try this page?

I'm not sure what kind of resources you have over there, but the US Land-Grant universities have "Extension Offices" that are awesome at this sort of thing.
posted by ArgentCorvid at 9:52 AM on May 8, 2008

I'm a bit paranoid about canned goods, I guess... instead of canning, we tend to freeze, dry, or pickle. I'm not sure if it's the chance of botulism that gives me pause or the potential for injury when using a pressure canner/cooker. More the latter, I think. I've read too many safety warnings and have a healthy distrust of my own capabilities.

So, I second the suggestion of freezing when possible. I grow a row of haricot vert each year and blanch-and-freeze the excess to great effect. Broad beans, which I've never grown in such volume, apparently freeze quite well also. Tomatoes we dry in a dehydrator. They take up so much less space, and are fabulous concentrations of tomatoey flavor. It all depends on what you want to do with them, though... if you're a pasta sauce person, you're probably better off canning.

Potatoes and onions are best just kept in the ground as late as possible, or in root-cellar like conditions. I very much doubt that you're going to manage to grow a crazy surplus of potatoes and onions using pots as you describe, but if you do and your flat is unable to accommodate them, you can bury them in a barrel or dustbin for long-term storage.

No courgettes / marrows? La.
posted by mumkin at 10:11 AM on May 8, 2008

tomatoes appear to be the safest (due to acidity)

Note that some of the newer varieties of tomatoes were purposely bred to be less acidic, so it wouldn't hurt to add a squeeze of lemon juice to all your jars (be they whole tomatoes or marinara sauce or whatever) before sealing them up.
posted by Asparagirl at 11:16 AM on May 8, 2008

Modern canning was invented at Napoleon's behest to feed French forces as part of the preparation for invading Russia. Practice anticipated Pasteur's theoretical justification by almost half a century, interestingly.

Should you find yourself beset by thoughts of just how easy it would be to mount a hostile winter takeover of Gazprom, stop eating your tomatoes immediately and contact a physician.
posted by jamjam at 11:28 AM on May 8, 2008 [1 favorite]

I wouldn't want to try to do pressure canning without explicit instructions, and pressure canners are pretty expensive and take up a lot of space, since I think the minimum I saw is 20 quarts to be able to pressure can pints of stuff.

Canning fruit/jam is super easy, and what you should be starting with if you've never canned before.

You may also be able to can pickles without a pressure canner, but I don't have a recipe in front of me to .

But as others have said, your first step should be to get a copy of a book on home canning and preserving and look at some recipes.
posted by leahwrenn at 11:57 AM on May 8, 2008

I've always wanted to read Love Lessons and the Art of Canning.
posted by buriedpaul at 12:10 PM on May 8, 2008

For what you're growing:

Water Bath:
tomatoes with 1/2 tsp citric acid (or 2T lemon juice) per quart
pepper jelly
dilly beans
pickles

Do NOT combine other veg with the tomatoes when water bath canning. Tomatoes hover on the edge of acidic enough to can by the water bath method as it is, so if you add eggplant or whatever, you'd need to pressure can it.

Pressure can:
beans
posted by Stewriffic at 12:20 PM on May 8, 2008

Canning is not like regular cooking, where you can be creative by adding/subtracting/substituting ingredients willy nilly. Successful water bath canning depends on maintaining the correct acidity or sugar level, and processing for the correct amount of time. For that reason, the path to success is following rigorously tested recipes to the letter.

Pressure canning is for low-acid foods, and has its own set of rules. You probably will want to stick with water bath canning, because that's where most of the fun is anyway.

As SuperSquirell notes, the Ball Blue Book is the classic guide to canning, but has a limited number of recipes, mostly old standards. The Complete Book of Small-Batch Preserving has a much wider range of recipes, and they tend to incorporate more exotic ingredients. Stocking Up is sort of the hippy-dippy classic, and has lots of recipes that use honey instead of sugar. My favorite, though, is The Joy of Pickling. This one actually goes beyond canning and into fermented pickles and so forth. Spicy pickled green beans, honey jalapenos, Russian pickled cherries--everything I've tried has been beautiful and delicious.

One thing that can make canning even more enjoyable is using these gorgeous jars from Weck.

Have fun!
posted by HotToddy at 12:30 PM on May 8, 2008 [1 favorite]

Slightly outside the mainstream canning/freezing techniques these three books offer more traditional methods:

*Wild Fermentation: The Flavor, Nutrition and Craft of Live-Culture Food

*Root Cellaring: Natural Cold Storage of Fruits and Vegetables

*Keeping Food Fresh: Old World Techniques for Recipes

The last is my favorite as it has tons of creative and interesting ideas for preserving food I'd never heard of. Alas it is out of print and selling for $75 a copy used. I preserved green beans with salt using a method from this book and 4 years later they look good as new (although I have been scared to eat them!).
posted by stbalbach at 7:00 AM on May 9, 2008 [1 favorite]