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It’s Time for Puttin’ It Up

Pressure Canner equiptment

Written By

Bonnie North

Written on

August 16 , 2017

You may remember your mother or grandmother’s stories about “puttin’ up” tomatoes or green beans every summer. Especially in rural communities this was a yearly ritual and women often gathered together to spend afternoons around a picnic table snapping the ends off green beans for hours, drinking sweet iced tea, and enjoying the camaraderie. And come those dark chilly days, there was nothing to compare with the flavor of home-preserved foods, bringing the scents and tastes of summertime to the winter’s table.

Now, home canning can be some work—but it’s also fun and satisfying. Once you’ve canned your own summer tomatoes you’ll never again be quite satisfied using store-bought for your sauces and soups. Doing it properly and safely is important though. A pressure cooker creates a lot of raw force and needs to be handled properly. Thankfully, modern pressure cookers are much safer and easier to use than the older versions our parents and grandparents managed with—I remember my mother accidentally sending a dozen quarts of hot beans flying all over the kitchen!

THE BASICS

Understanding how to prevent food spoilage is the key to canning safety. Molds, yeasts, and bacteria are the major causes of food spoilage, and the most important factor in controlling these “spoilers” is controlling the environment that encourages their growth. The “processing” in a canner destroys potentially harmful microorganisms and drives air from the jar. As the jars cool, a vacuum is formed and the lid seals tightly to the jar, preventing other microorganisms from entering and contaminating the food. 

Canning interrupts the natural decaying process by heating the food to a specific temperature and holding it there for a specific period of time. The word specific is important here! Refer to reliable recipes (The Ball Complete Book of Home Preserving, edited by Judi Kingry and Lauren Devine, is an excellent source) or other good sources for instructions. Select the method of canning based upon the acid level of the food being canned. The processing methods are NOT interchangeable. Also, the “head space”—room for the contents to expand during heating inside the jar—will vary because some foods swell more than others and require additional head space. In general, leave 1 inch of head space for low-acid foods, like meats or vegetables; 1/2 inch for acidic foods like fruits and tomatoes; and 1/4 inch for juices, jams, jellies, pickles, and relishes. Processing times also vary greatly depending upon the type of food being canned and the jar size you are using. Refer to each recipe for correct processing information regarding length of processing, pressure required and so on.

If all the steps to canning are followed properly, your food will be safely preserved and can last for many months in the jar.

CANNING EQUIPMENT

  • Glass canning jars
  • Packing funnel
  • Clean sponge for cleaning jar rims
  • Jar lids—CAN ONLY BE USED ONCE The rubber gasket will NOT seal again. Discard, or permanently mark as used, after opening the jar.
  • Magnetic lid lifter
  • Spatula for removing air bubbles from packed jars
  • Jar rings—can be reused over and over
  • Pressure cooker or large canning pot with cover
  • Rack for elevating jars within the canner
  • Timer
  • Tongs for removing hot jars
  • Pot holders and towels
  • Jar opener

PREPARATION

When you are ready to can, carefully remove any small diseased areas or bruised spots in your food. Discard moldy, insect-damaged, and overly ripe foods. Prepare food for loading into jars.

  1. Place lids in a pan of warm water and heat gently to soften the rubberized rim. Do not allow the water to boil, which could crack the rubber.
  2. Load jars using the funnel, leaving proper head space for contents to expand during processing.
  3. Run a spatula down the sides of each jar to tease out any air bubbles that may be inside.
  4. Wipe the rim of each jar carefully so that there will be a clean and uninterrupted seal between the glass rim of the jar and the rubberized circle inside the lid.
  5. Lift each lid from the warm water without touching them, using the magnetized lid lifter and gently drop onto the rim of each jar. Without touching the rubberized circle inside the lid, position them centered on the jar. Touching the rubberized circle can interfere with the sealing process. 
  6. Screw jar rings onto the jars.  The ring should be fully screwed on but not overly tight.  The rubberized circle inside the lid seals with the glass rim of the jar; the ring is merely to keep the lid in place during the canning process.  It will be removed to check the seal when the jars have fully cooled.

THE TWO METHODS

There are two methods of home canning: the hot water bath method and the steam pressure-canner method. The pH, or the natural acidity, of the food you are preserving determines which method must be used. The processing methods are NOT interchangeable.

Foods naturally high in acid, such as tomatoes, sauerkraut, or pickles, are safe to process by the hot water bath method because the acidity of the food prevents the growth of hard-to-kill bacteria such as staph or botulism.

However, staph and botulism can be dangerous in a low-acid environment. These bacteria cannot be completely destroyed by the hot water bath method since temperatures above the boiling point of water must be reached and maintained for a period of time. The pressure cooker is designed to seal so tightly that the water cannot all turn to steam and escape, thus pressure builds and a higher temperature can be reached. A pressure-cooker must be used to preserve low-acid foods safely.

HOT WATER BATH METHOD

  1. Fill canner half full with warm water.
  2. Load jars into rack and lower rack into the water.
  3. Add additional hot water until the water level is at least 2 inches above jar tops.
  4. Cover canner.
  5. Bring to a hard rolling boil and adjust down to a soft rolling boil. Set timer for the number of minutes recommended for processing.
  6. When timer sounds, turn off heat and allow to cool down for about 15 minutes before opening canner. Be certain to lift the canner lid toward you so that the steam moves away from your face. There will be steam coming out!
  7. Using tongs, remove the jars and set on a towel to finish cooling. Remove rings and check seals only when the jars are fully cooled. Do not replace the rings. If the rings are stored on the sealed jars they can corrode and become difficult to remove. Rings can be kept for re-use, but the lids cannot.

PRESSURE CANNER METHOD

Parts of a pressure canner:

  • Base
  • Rack
  • Locking lid with rubber gasket
  • Pressure vent pipe
  • Pressure gauge
  • Pressure regulator cap
  • Safety valve, in case of over-heating or over-pressurizing
  1. Check canner equipment, making certain all vents are cleared, rubber sealing gasket is secure, and so on.
  2. Put rack in bottom of canner and add 2-3 inches of water.
  3. Load jars onto rack.
  4. Lock canner lid firmly into place.
  5. Heat until steam begins to flow from the steam vent pipe.
  6. Allow steam to escape for a full 10 minutes.
  7. Place pressure regulator cap on steam vent.
  8. Allow pressure to build until the desired pressure is reached—adjust heat to maintain pressure at that level.
  9. Set timer.
  10. When processing is complete, turn off the heat and allow canner to cool naturally. Do not remove the pressure regular or open the canner until the canner has depressurized and returned to zero pressure.
  11. Remove pressure regulator and wait at least 2 minutes before opening canner.  Be certain to lift the canner lid toward you so that the steam moves away from your face.
  12. Allow jars to sit for 5–10 minutes in the canner to adjust to the lowering of temperature.
  13. Using the tongs, lift jars from canner and set on a towel to continue cooling.  Remove rings and check seals when jars are completely cooled. Do not replace the rings. If the rings are stored on the sealed jars they can corrode and become difficult to remove. Rings can be kept for re-use, but the lids cannot.

STORAGE

Before placing the cooled jars in your pantry, wipe off the lids and jars to clean away any food residue that may have escaped during the canning process. Label each jar with the date it was canned and the type of food preserved. Food that has been properly canned can last almost indefinitely but chemical changes will occur over time. This can affect the color, flavor, texture, and nutritional value of the canned food, so labeling, dating, and using old stock first is important.

When opening the jars check to be certain that the lid is still tightly sealed. You’ll need the handy jar opener to crack the seal and to open the jars. If the lid is easily removed, DO NOT USE THE PRODUCT. Check for any disagreeable odors, mold, sliminess, gassiness, or fermentation. If a jar has become contaminated, discard the jar, lid, contents, and any cloths or sponges that may have come into contact with them immediately.

Canned foods are best stored at temperatures between 50 and 700F. Freezing can cause the contents and the glass to expand and can break the seal.

Have fun!

About the Author

Bonnie North

Bonnie North

Bonnie North came to Vermont from Maryland, where she published a local foods guide called Baltimore Eats. She was a founding member of the Chesapeake Sustainable Business Alliance and the leader of the Baltimore chapter of Slow Food, USA. As the former owner of Valley Provisions Market in Bellows Falls, she was one of the investing members and first business customers of the Windham Farm and Food network. Bonnie received her Permaculture Designer’s Certificate in 1996, studying with West Coast teachers Jude Hobbs, Rick Valley, and Tom Ward. She received a Permaculture Teacher’s Certificate from teacher Dave Jacke in 2010. She now lives in southern Vermont.

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