Canning can-do

New cookbooks and apps, “can-ins” organized on Twitter, effusive blogs: Canning is no longer just our grandmother’s thing. Thanks to the local-food movement and booming interest in taking control over what we eat, a very modern revival is under way.

Stock up

With the fall bounty in farmers’ markets tempting cottagers to buy too much, there’s no better time to catch the trend. You don’t need a lot of specialized equipment to get started, not even one of those purpose-built blue-speckled canners. Use any lidded pot that’s at least 3″ (7.5 cm) taller than your jars. Other canning must-haves include basic kitchen utensils and a few specialty tools:

  • Glass Mason jars with two-piece, self-sealing lids (a flat sealing disc with a rubber gasket, and a metal screw band). Wash new jars and sealing discs. You can reuse jars and screw bands if they’re in good condition; sealing discs, however, should be used only once.
  • A wire rack to keep jars off the bottom of the pot. They’re sold with canning supplies, but a small baking rack, a metal trivet, or even screw bands tied together with twine will do the trick.
  • A jar lifter or heat-resistant, waterproof silicone gloves for getting hot jars into and out of the pot.
  • A timer, a slotted spoon or tongs, a ladle, a plastic knife for removing air bubbles, and labels for the jars. A wide-mouth funnel and a magnetized “wand” (to retrieve sealing discs from hot water) are both helpful but not essential.

Canning basics

The steps below don’t apply to all canning recipes; you can safely use the boiling-water method for the recipes on these pages, which are acidic enough to inhibit harmful bacteria. Low-acid recipes need special methods and equipment, including a pressure canner.
Feel free to adjust spices and salt to taste, but tinkering with other ingredients and quantities could reduce acidity. (In that case, refrigerate the food instead of processing it, and eat it within a month.)

Before you start

  1. Organize your tools. Because jar size affects process-ing time, use the size specified. Fill canning pot two-thirds full with cold water.
  2. For recipes that are quickly prepared, put the pot on high heat immediately; otherwise, begin heating the water about 30 minutes before you finish the food prep. Once the water comes to a full boil, reduce heat to low. Place clean jars upright on the rack in the pot, partly submerged in hot water, and cover pot. For these recipes, sterilizing jars before filling isn’t required, since they’ll be processed for at least 10 minutes. But the old canning adage, “Hot food into hot jars, and hot jars into hot water,” still applies. “Hot” is simmering, not boiling: 180°F (82°C).
  3. Heat a kettle of water, in case you need more to cover the filled jars.

Filling the jars

  1. When the food is ready for the jars, put the sealing discs in a heatproof bowl and ladle hot water over them to soften the rubber gaskets.
  2. Using a jar lifter or silicone gloves, lift a jar, pouring the water inside the jar back into the pot. Fill jar with hot food, following the recipe directions. A wide-mouth funnel prevents sticky spills. Leave 1/4″ (0.5 cm) headspace between top of food and jar rim in 250 ml jars, and 1/2″ (1 cm) in 500 ml jars. If you end up with a partially filled jar, simply refrigerate and use within a month.
  3. Remove trapped air bubbles by slowly running a plastic knife (or a canning de-bubbler tool) around jar wall. Wipe rim clean.
  4. Using gloved fingers or magnetized lid wand, place a warm sealing disc on jar. Add screw band, twisting until finger tight. (Overtightening bands prevents jars from venting and can lead to seal failure.)
  5. After filling each jar, place on rack in pot, leaving 1/2″ (1 cm) between jars. When pot is full, add more hot water if needed to cover jars by 1″–2″ (2.5-5 cm). Cover pot with lid. (If all the jars won’t fit, keep remaining food hot while one batch is processing, then fill and process the rest of the jars.)

Processing

  1. Bring pot with filled jars to a boil on high heat. When water reaches a full boil, set your timer for processing time in the recipe. Add 5 minutes for elevations above 1,000 ft. (306 m); 10 minutes for 3,000–6,000 ft. (915–1,830 m). Maintain a gentle boil for entire processing period. When timer rings, turn off heat, take off pot lid, and leave jars in pot for 5 minutes to settle.
  2. Using a jar lifter or silicone gloves, place jars on a tea towel to cool, away from drafts. Leave upright and undisturbed for 12 hours.
  3. When jars are cool, press on the disc; if it springs back after you remove your finger, the seal has failed. Refrigerate and use within a month.
  4. Label and date each jar, store in a cool, dark place, and enjoy your preserves within a year.