How to Can Food

If it’s difficult to imagine a pantry of jams or pickles that you’ve canned yourself, it shouldn’t be. Anyone who can boil a pot of water can preserve foods at home – and there’s a comforting feeling to knowing exactly what’s in the food you’re preserving.

What Does “Canning” Mean?

The process involves placing food in jars and heating the jars to a temperature that destroys microorganisms that could cause the food to spoil. Air is driven from the jar during heating, and as it cools, a vacuum seal is formed, which prevents air (and microorganisms) from getting back in.

The National Center for Home Food Preservation recommends that canned food should be used within a year of its canning date.

Methods for Canning Food

There are two kinds of canning. One is boiling water bath canning, which requires no special equipment. The other is pressure canning, which requires a pressure canner (not the same as a pressure cooker).

Boiling water canning is suitable for preparing high-acid foods – such as fruits, pickles, sauerkraut, jams, jellies, marmalades and fruit butters – to be shelf-stable. Low-acid foods such as meats, seafood and vegetables require heating to at least 240°F, a temperature that can only be reached with a pressure canner.

In this beginner’s guide, we’ll focus on boiling water bath canning.

What You Need

There are only a handful of items needed for boiling water bath canning:

  • Jars: Canning jars come in many sizes. Most recipes use pint- or quart-sized jars.
  • Canning Lids/Rings: Home canning lids and rings work as a two-piece vacuum cap. Your jars should come with the lid and ring, but you can also purchase these separately if you’re reusing old jars. Rings can be reused if they’re in good condition, but lids may not effectively seal after one use (and shouldn’t be reused).
  • Jar Lifter: This clamps onto jars and makes it easy to pull them out of boiling water.
  • Canning Funnels: These wide-mouth funnels help you easily transfer food to the jars.
  • Tall Canner (or Pot) with Lid: Make sure it’s big enough to fit your canning jars while leaving room for water to cover them. You also need a small wire rack that keeps the jars from touching the bottom of the pot.

What is the Process of Canning?

Here are the steps to follow for boiling water bath canning:

  • Place clean jars on a wire rack in the bottom of the canning pot. (As a substitute for the rack, you can use a kitchen towel.) Add water to fill the jars and cover them by at least 1".
  • Cover the pot and bring the water to a rolling boil over high heat. Boil the jars for 10 minutes to sterilize them.
  • Line a rimmed baking sheet with a clean towel or a rack. Reduce the heat in the pot to a simmer and remove the jars from the water using a jar lifter, carefully pouring the water in the jars back into the pot. Place the jars upside down on the baking sheet to air dry.
  • Use the same water to prepare the lids and rings by gently simmering them for 10 minutes, making sure not to boil. Then turn off the heat and keep the lids and rings in the water until ready to use. 
  • Now it’s time to prepare the food you’re canning. Cook your recipe according to its instructions.
  • Once your food is ready, use your canning funnel to ladle your food into each jar. Remove the funnel and see how much space there is between the top of the food and the top of the jar. Leave the recipe-specified amount of headspace. Wipe the mouth of the jar with a paper towel or damp cloth.
  • Use the jar lifter to remove the lids and rings from the water. Place a clean lid on each jar and screw on the ring – though not too tightly, because air needs to escape during processing.
  • Use the jar lifter to lower each jar back onto the rack in the pot. Once all jars are in the canner, put the lid on top and bring the water to a vigorous boil. Each recipe will tell you a specific processing time for how long to boil. After turning off the heat and removing the canner lid, wait 5 minutes before removing the jars.
  • Use the jar lifter to move the jars to a thick towel, wire rack or wooden cutting board. Don’t tighten or adjust the rings. Lids may make a popping noise as the jars cool. That’s one sign of an airtight seal. When the jars have cooled 12-24 hours, remove the rings and press down on the center of each lid with your finger. If the lid doesn’t move, the jar is sealed; you can screw the ring back on and store the jar in a cool, dark place. If the lid center depresses and pops up again, it means the jar isn’t sealed. Unsealed jars can be placed in the fridge (and the food should be eaten within a week).

DIY Canned Blueberry Pie Filling

To get started canning, try this tasty recipe:

For more meal inspiration, check out our blog and explore our Easy Meal Solutions page.