By Sue Weaver

About the Author: Sue Weaver is a freelance writer who raises horses, gardens and cans with her husband, John, on their hobby farm in Arkansas.

Is it safe to eat canned fruits and vegetables? And is canning fruits and vegetables something worth learning to do? In a word: yes. However, there is more to preserving safe, tasty, nutritious canned fruits, vegetables and meats than hauling out Grandma’s old pressure canner. Here are the facts about canning instructions and methods.

In this article... How To Preserve Safety and Benefits What You Need to Get Started Hot and Cold Packing Online Resources Canning History Lesson

Because modern hybrid vegetable and fruit varieties are often less acidic than heirloom varieties and modern canned goods are generally stored under vastly different conditions than they were just decades ago, in 1989 our United States Department of Agriculture updated its home canning guidelines and declared certain old-fashioned canning methods verboten.

Extension Services in every state reprinted canning instruction manuals to reflect the USDA’s findings. In 1994 it released its own definitive work, Complete Guide to Home Canning.

Unfortunately, many home canners aren’t aware of these safety updates and still follow instructions from old books and bulletins. Others contend “the old ways are best.”

How To Preserve Pressure Canner: Cook food according to specific canning recipe. Run two to three inches of hot water into the canner. Arrange packed, lidded jars on the rack and secure the canner’s lid. Heat at the highest setting until steam rushes from the uncovered vent or petcock. Maintaining top heat, vent steam for 10 minutes, then close the petcock or place the weighted bobber on the vent. Begin timing when the dial gauge indicates the correct pressure is up or when the weighted gauge begins to rock or jiggle. Regulate heat to maintain pressure at or slightly above the recommended gauge pressure. If it drops below that point, bring the pressure back up and begin timing from the beginning. When the time is up, switch off the heat and let the canner depressurize at room temperature. You’ll know it’s depressurized when its dial gauge returns to zero or the canner doesn’t hiss when its weighted gauge is gently nudged. When depressurized, open the petcock or remove the weighted bobber. Wait 5 minutes. Unfasten the lid and lift it away from you so out-rushing steam doesn’t singe your face. Remove jars with a lifter and arrange them on towels or a rack (never a cold, bare surface) to cool, allowing at least an inch between jars. Water Bath Canner: Cook food according to specific canning recipe. Fill the canner halfway full of water. Place clean towels in the bottom if you’re not using a canning rack. Heat to 140 degrees for cold-packed foods, 180 degrees for hot-pack. Arrange packed, lidded jars on the rack and lower it into the water or use a jar lifter to place jars into the rack or submerged towels, one at a time. Add enough boiling water to cover the jars by at least one inch. Don’t pour it directly on the jars. Turn heat to its highest setting until water boils briskly; cover the canner and begin timing according to your recipe. Adjust the heat to maintain a gentle boil throughout processing. Add more boiling water as needed. When time is up, switch off the heat, remove the lid, and fish out the jars using a jar lifter. Place them on towels or a rack (never a cold, bare surface) to cool, allowing at least an inch between jars. Storing home canned food: When fully cooled (12 to 24 hours later), remove screw bands, leaving only flat lids on the jars. Wash, rinse and dry the bands before storing. Test the lid seals by gently thumping them with the back of a teaspoon. A clear, ringing sound indicates a good seal, as does a concave lid. Remove lids from unsealed or dubious jars and check their rims for nicks and irregularities. Transfer the food to another jar if necessary and fully reprocess it within 24 hours. Or refrigerate and freeze or eat it within 24 hours. Wash each sealed jar and lid, rinse and dry. Label and date them. Store canned food in a clean, dark, dry spot away from heat sources such as water heaters, furnaces, kitchen ranges, hot pipes and direct sun. Avoid attics and storage buildings. Top

Between October 24, 2000, and January 10, 2001, the Center for Home Food Preservation in conjunction with the University of Georgia called 5,259 randomly selected households across the United States; 1,244 households reported freezing or home canning in 1999.

The Center polled 501 of these home-canning households with these startling results:

• Only 19 percent followed canning instructions gleaned from cookbooks and County Extension bulletins (and some of these were badly outdated); 48 percent obtained instructions solely from friends or relatives.

To preserve high-acid products such as fruits, pickles and tomatoes, the USDA recommends water bath or pressure-canning methods.

Old-style, open-kettle canning as well as oven and microwave procedures are deemed unsafe.

Yet, 21 percent chose the open-kettle method and four percent canned in ovens. Only 58 percent of the home canners polled used the water-bath method and 15.5 percent used a pressure canner.

Furthermore, when canning low-acid foods like vegetables, poultry, seafood, meats and combinations such as stews and salsa, processing in a pressure canner is the only way to safely kill botulism spores.
 
Still, only 30 percent of the canners polled always used a pressure canner; 39 percent used water-bath canners, 29 percent used pressure cookers, 15 percent used the open-kettle method and three percent used the oven. Obviously, things need to change.

Safety and Benefits
Be sure to follow canning instructions exactly for your and others safety. A safely canned food yields numerous benefits.

Safety
Clostridium botulinum, the deadly neurotoxin that causes botulism, thrives in under-processed, low-acid, home-canned goods.
 
A single nibble or sip of botulism-laced food, ingested as soon as three or four days after processing, can prove fatal. Why take that risk? C. botulinum and the other bacteria that contribute to spoilage are easily destroyed when cooked for the right amount of time at 240 to 250 degrees F—the temperature in a properly-regulated pressure canner.

Benefits
Canned foods are often more wholesome than weeks-old “fresh” produce at the market.

Even refrigerated, the nutrient content of fruits and vegetables begins declining at harvest. Within a week, up to 50 percent of certain vitamins may be lost. However, although heat destroys one-third to one-half of Vitamins A and C, riboflavin and thiamin, once these items are canned, the process slows to five to 20 percent per year.

Canning is economical. The same equipment—including canning jars—can be used year after year. Only lids must be purchased new each canning season.

Canning lets you savor favorite foods all year, including out-of-season and homegrown, organic goodies. It’s convenient—precook and can dried beans for chili recipes or chicken to simmer with those dumplings.
 
It beats freezing: stored canned goods don’t spoil when the power goes off. Most frozen foods claim a one-year life expectancy. But with only slight decline in looks and flavor, canned items can last for two to three years or more.

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What You Need to Get Started
If you’re convinced and want to try canning this year, here’s what you’ll need to get started:

• Reliable canning instructions and recipes
  Check the copyright date on material you may already have on hand. If it’s dated before 1989, it’s best to discard it. Take heirloom and other favorite recipes to your County Extension for updating or compare them to modern recipes and based on those, add significantly to their processing times.

Reliable canning instruction and recipes are free and abundant. Pick up bulletins from your County Extension agent or download them from the Internet. Phone or e-mail canning-supply companies such as the Alltrista Corporation (makers of Ball and Kerr canning jars and lids), and ask for free brochures. Many offer inexpensive materials like Alltrista’s 120-page classic, The Ball Blue Book: Guide to Home Canning, Freezing & Dehydration; 32nd Edition, available directly from Alltrista (see “Resources” on page 90). If in doubt, pressure canning (according to modern USDA recommendations) is always your safest ploy.

• Wholesome, properly handled food
  When possible, grow or pick your own fruits and vegetables. For optimal flavor, nutrition and appearance, can them within six to 12 hours of harvest. Choose fully ripe (but not over-ripe), bruise- and blemish-free produce.

Hot pack, cold pack: What does it mean? HOT: To hot pack fruits and tomatoes, preheat them in boiling syrup, juice or water, loosely pack into warm jars, seal, then process the jars in a water-bath canner. Because they’re partially cooked, hot packed products require less processing time. Shrinkage has already occurred, so more food can be packed into each jar. Best hot packed: Tomatoes, apples, applesauce and rhubarb. COLD: Cold pack (aka “raw pack”) works best for delicate items like raspberries. Cold packing is quicker and easier but requires longer processing times. To cold pack fruits, cram them tightly into jars, pour on boiling syrup, juice or water, enough to fill spaces and submerge their contents and process as above. Apricots, most berries, cherries, peaches, pears and plums can be hot or cold packed, whichever you prefer. Either method: leave enough head space (check your recipe; usually 1¼2 to one inch between food and lid) to allow for fruit expansion and bubbling liquids. And remove excess air prior to sealing by inserting a rubber spatula, plastic knife or a chopstick between each jar and its contents and coaxing those bubbles free. TOP

Harvest, pick or buy only the amount you can process in two to three hours. Rinse and lightly scrub fruit and veggies but don’t soak them prior to canning.

• Canner
  If you put up vegetables, including low-acid tomatoes, poultry, meat, seafood or processed entrees such as chili or stew, you’ll need a pressure canner. Grandma’s pressure canner, if she had one, was a heavy, bulky monster with thick walls and a cumbersome clamp-on lid. Redesigned in the 1970s, today’s models are sleek, thin-walled and lightweight, featuring replaceable gaskets, twist-on lids with automatic cover locks, one or more safety valves and dial or weighted pressure gauges.

Pressure canners range in size and price from Mirro, Presto and Maitre’s petite 4.2 models (they handle three-quart jars and list for around $45 but often sell for much less) to the enormous All-American 941 (19 quarts or 32 pints and close to $350), although the average pressure canner holds seven quarts or eight to nine pint jars in a single layer or 18 pints in two and retails for $100 to $150.

Used canners purchased at yard sales or on the Internet may or may not be bargains. Before buying one, make certain all parts are present and functioning. You can pick up replacement gaskets, dial gauges, counterweights and safety valves for modern canners at most hardware stores or order them from manufacturers and canning supply outlets, but parts for antiquated canners are all but extinct.

Dial-gauge models, like those built by Presto and All-American, accurately measure the appliance’s internal pressure and are preferred by many home canners. One drawback: gauges must be checked for accuracy before every canning season and again if dropped or mishandled.

Weighted-gauge canners, manufactured by Mirro and Maitre, feature a steam vent or petcock closed by a weight that jiggles and hisses two or three times per minute while the canner is suitably pressurized. Both incorporate rubber or rubber-like lid gaskets to form a tight seal. The gaskets in modern canners are permanently pre-lubed at the factory but those in older models should be periodically slathered with vegetable oil. Nicked, gummy, stretched or dried gaskets don’t properly seal, causing steam leaks and under-processed canned goods. Replace them.

Never force-cool any pressure canner. Cool down is factored into processing time. Dousing any canner with running water causes lid-seal failures and liquid loss from jars. Older models’ lids can warp, resulting in unfixable steam leaks.

Because water boils at lower temperatures as altitude increases, and canning instructions are generally calculated for elevations below 1,000 feet above sea level, unless their gauges are adjusted, temperatures inside pressure canners used at higher elevations will be incorrect. Unsure if you’re affected? Ask your nearest County Extension agent for assistance. Don’t omit this step.

While you can put up fruit, high-acid or acidified tomatoes, relishes, pickles, jams and jellies in a pressure canner with the lid clamped in place and the exhaust valve (petcock) open, the same foods can be processed faster in a water-bath canner. You may want to buy both kinds.

Online Resources Canners National Presto Industries (Presto canners, parts) (800) 877-0441 Wisconsin Aluminum Foundry Company (Makers of All-American canners) (920) 682-8627 Pressure Cooker Outlet (Presto, Mirro, All American & Maitres Pressure Cookers & Parts; canning books and supplies) (800) 251-8824 Canning supplies Alltrista Corp. (Makers of Ball and Kerr canning lids, Ball Blue Book and other brochures, online canning instructions, recipes, FAQs, archived newsletters); Hotline: (800) 240-3340; Order: (800) 392-2575 Kitchen Krafts (Free catalog) (800) 776-0575 or (563) 535-8000 Home Canning Supply (Free catalog) (800) 354-4070 Home Canning labels: Label Creations A Lotta Labels  Useful Web Sites: Food Preservation Links Extensive; links to reliable university-published information. USDA Complete Guide to Home Canning Print chapters or topics; download them as .pdf files. National Center for Home Food Preservation Instructions, FAQs, multimedia presentations, information requests. Home Canning Pressures and Processing Times Four-page .pdf download, very complete, very valuable. Troubleshooting Guides Common Canning Problems (Clemson University) Cooperative Extension Services Reliable Canning Recipes: Pickling Recipes and Canning Links Pickles and Relishes A lot of them, including sauerkraut. Salsa Recipes for Canning Tomato Recipes to Preserve an Abundant Harvest Jam and Jelly Recipes Let’s Preserve Fruit Pie Fillings

Water-bath canners, sometimes called boiling-water canners, are deep, porcelain-covered steel or aluminum pots fitted with snug-fitting lids and removable canning racks. They cost $10 to $30 at hardware stores or the large discount chain stores. With canning racks removed, they can be used to fix hefty batches of food for group feeds or for freezing. In water-bath canning, packed jars are immersed in at least one inch of boiling water for an allotted time—nothing could be simpler!

• Canning jars
  Buy them new, packed one dozen per package, at grocery stores, hardware stores and the like, in 1¼2 pint, pint, 1 1¼2 pint, quart and 1¼2-gallon sizes, and in standard and wide-mouth configurations. Most popular are pints and quarts, with canners designed to contain these sizes. Wide-mouth jars, measuring three inches across, are easier to fill, empty and wash than their standard (2 3¼8”) mouth cousins.

  Jars are safe to reuse if they’re designed for use with modern, flat canning lids and screw-on rings. Scaly, film-covered jars are salvageable. Soak them for two to three hours in one cup of five percent acidity vinegar to one gallon of water solution, then hand or machine wash as usual. When considering a box of used canning jars, glaze your forefinger around their rims, checking for chips, nicks and the sort of uneven surface that will prevent your canning lids sealing. With use, jars do weaken and crack. New ones are often a better buy.

Don’t buy or save commercial mayonnaise containers to use as canning jars. They’re neither heat-tempered nor sturdy enough to withstand home canning, especially more than once. A mayonnaise jar’s narrower rim surface makes seal failure likely and it could shatter during processing or even explode when the canner is opened. If you must use recycled food containers, use them only for water-bath canning, never inside a pressure canner.

• Canning lids
  Not so many years ago, canning jars were sealed with porcelain-lined, zinc screw-on lids with separate “jar rubber” gaskets. Antique jars are still around but finding new rubber gaskets is iffy and the USDA no longer endorses their use. The same goes for old-fashioned jars with wire-bail-attached glass lids and jar rubber seals.

The only safe canning topper is today’s self-sealing, two-piece vacuum lid. Its flat metal lid has a strip of rubbery gasket compound molded to its crimped underside. Heated, the compound softens and semi-seals while still allowing air to escape from the jar. This seal becomes airtight as the finished product cools and a vacuum forms.

During processing, the lid is clamped in place by a metal screw-on band or ring, which is removed after the finished product cools. Lid flats must never be reused but screw bands, if properly handled, will last indefinitely. Lids are sold as two-piece units or flats only.

Canning lids boast a five-year shelf life, although with age, more seal failures occur. It’s best to buy just enough for a single canning season. Over 30 companies manufacture these lids and not all work precisely the same. Always read and follow manufacturer’s instructions when prepping canning lids for use.

• Accessories
  While most of the essentials you’ll need for processing food are standard kitchen tools, a few items are specific to canning.

Spooning food into canning jars is a lesson in frustration; wide-mouth plastic funnels make filling canning jars a breeze.

You’ll need a jar lifter—a specially-shaped set of tongs with rubber-coated handles—for fishing blistering hot jars out of your canner.

For cold-packing fruit, a small-bladed plastic or rubber spatula will coax bubbles out of jars before processing. Some instructions recommend a knife but metal causes certain fruits to turn odd hues.

To prevent breakage, you shouldn’t pack cool jars with
warm food. Bring them to a simmer in a kettle of water and hold them there till you’re ready to fill them. Use a large kettle that will hold all the jars for one batch. A water-bath canner is ideal.

An accurate kitchen timer is a must, as are measuring cups and spoons. Canning is an exacting science. Time and volume measurements must be precise.

Saucepans for warming lids; colanders for draining product; knives and cutting boards for peeling and chopping; pot holders or mitts to protect your hands; a big spoon for stirring and towels to cool your canned goods upon.

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Home canning is a safe, economical way to put delicious, nutritious food on your table at every meal. Blackberry jam for breakfast, tasty home-canned chili for lunch, green beans from your garden, peaches from your trees—delicious! Give canning a try. When that first batch of jewel-like jars stands cooling on your countertop, you’ll be thrilled you did.

Canning History Lesson In 1795, the French government offered 12,000 francs to the man who could devise an effective food-preservation method designed to feed her army and navy. In 1810 Emperor Napoleon Bonaparte himself presented the prize to chef Nicolas Appert. His “Appert method” involved sealing foodstuffs inside bottles and jars using cork, wire and sealing wax, then immersing them in boiling water for several hours. Appert couldn’t explain why it worked, but it did. John L. Mason, a 26-year-old tinsmith from New York City patented his famous Mason jar canning system in 1858. Glass “Mason jars” were embossed with the legend, “Mason’s Patent Nov 30. 1858” as late as 1920. The Ball Company, founded in 1884 as the Wooden Jacket Can Company, became the world’s first mass producer of canning jars and lids. By 1892 it employed 1,000 workers and operated three factories in New York and Indiana. Ball published its first Blue Book (now in its 32nd printing) in 1909 and introduced the first jelly glasses in 1920. During World War II, as part of the war effort, our government encouraged Americans to grow and can their own food, thus reducing the commercial canning industry’s need for steel and tin—commodities vital to the war effort. In the 1950s and 60s, due to the advent of TV dinners and fast food restaurants, Americans became disenchanted with home canning. However, as food prices skyrocketed in the 1970s and thanks to the “back-to-the-land” movement of that era, home gardeners hauled out their canners and began preserving foods again. In 1996, the Alltrista Corporation released results of a study showing that 28 percent of Americans home canned at least one food product the previous year. TOP

This article first appeared in the Fall 2002 issue of Hobby Farms magazine. Pick up a copy at your local newsstand or tack and feed store. Click Here to subscribe to HF.