Our Step-by-Step Guide to Making Jam and Canning It (2024)

Our step-by-step guide takes you through the process.

Lynn Andriani

Lynn is a freelance writer for MarthaStewart.com.

Editorial Guidelines

Updated on April 25, 2024

Our Step-by-Step Guide to Making Jam and Canning It (1)

Canning is a technique that can (understandably) intimidate even the experienced cook: All that steam, heat, pressure, and glass can be a lot to keep safe tabs on. Yet the process of canning has the potential to yield such satisfying rewards. A pantry full of jam that will keep for a year (or more) is a treasure trove for toast lovers, not to mention a cache of gifts ready for the giving.

In this step-by-step guide, we explain the basics of canning, including an overview of the tools you'll need and important safety tips. After you've mastered the essentials, you may want to try other fruit jams or easy vegetables such as corn, cucumbers, green beans, or tomatoes. And once you're comfortable with these, you'll be ready to move on to more elaborate recipes. Although preserving can be hot, sticky work, we're sure you'll find the rewards are glorious.

How to Can Tomatoes the Right Way

What You'll Need

Our Step-by-Step Guide to Making Jam and Canning It (2)

Boiling-water canner or similarly deep pot (think lobster-pot size)
Canning rack (some canners come with canning racks)
Jars, lids, and bands
Jar-lifting tongs
Headspace-measuring tool
Clean dish towels
Labels
Timer

Canning supplies are available at hardware stores, supermarkets, and supercenters and from Lehman's.com. For more information on supplies, consult freshpreserving.com (the official website of Ball, the consummate canning resource).

Safety Tips

Be sure to check your supplies before you start. Bands should screw evenly over lids; jars should be free of scratches or chips, which could cause seal failure during processing or sealing.

Next, remember that you should not reuse lids. Jars and bands can be recycled, but the flat lids are for one-time use only.

Last but not least, cool carefully. Never place hot jars directly on kitchen counters; the glass might crack. Use a dish towel or a cooling rack instead.

Ingredients

Yield: Makes four half-pint jars

3 pounds plums (or other stone fruit such as peaches, nectarines, or apricots), pitted and quartered
3 cups organic sugar
1 tablespoon fresh lemon juice
3⁄4 teaspoon kosher salt

How to Make Jam

01of 09

Wash Jars and Lids and Sterilize Jars

Our Step-by-Step Guide to Making Jam and Canning It (3)

Wash jars and lids with soapy water, dry bands, and set aside. Place jars in a large pot and cover with water. Bring to a simmer. Put lids in a separate pot of hot water. Leave jars and lids in water until ready to fill.

02of 09

Mix Fruit, Sugar, Lemon Juice, and Salt

Our Step-by-Step Guide to Making Jam and Canning It (4)

Combine plums, sugar, lemon juice, and salt in a stockpot over high heat.

03of 09

Bring to a Boil

Our Step-by-Step Guide to Making Jam and Canning It (5)

Bring to a boil, mashing with a potato masher. Skim scum off top.

04of 09

Boil, Skimming and Stirring Fruit

Our Step-by-Step Guide to Making Jam and Canning It (6)

Boil, skimming and stirring frequently, until bubbles slow and you can see chunks of fruit showing through top and mixture clings to a spoon, falling off in languid clumps, 10 to 12 minutes. Pick up and discard skins with a fork, if desired.

05of 09

Ladle Jam Into Jars

Our Step-by-Step Guide to Making Jam and Canning It (7)

Lift jars out of hot water one at a time, draining water. Ladle hot jam into hot jars using a wide-mouth funnel, leaving 1⁄2-inch headspace. Slide a nonmetallic spatula or chopstick between jam and jar to release trapped air bubbles.

06of 09

Wipe and Seal Jars

Our Step-by-Step Guide to Making Jam and Canning It (8)

Wipe rim and threads of jar with a clean, damp dishcloth. Remove lid from hot water. Place lid on jar. Screw band down evenly and firmly, just until resistance is met.

07of 09

Process in Hot Water Canner

Our Step-by-Step Guide to Making Jam and Canning It (9)

Place in canner and lower into water. Put lid on canner. Bring water to a boil. Start keeping time after water comes to a rolling boil. Process 1⁄2 pint jars for 10 minutes at a gentle but steady boil.

08of 09

Dry Jars and Let Cool

Our Step-by-Step Guide to Making Jam and Canning It (10)

Turn off heat and remove canner lid. Let canner cool five minutes, then remove jars and set them upright on a dry towel or rack. Do not retighten bands. Let jars cool 12 to 24 hours.

09of 09

Check Jars Have Good Seal

Our Step-by-Step Guide to Making Jam and Canning It (11)

Once cool, check lids for a good vacuum seal by pressing on center of each. If center is pulled down and does not flex, remove band and gently try to lift lid off with your fingertips. If lid does not flex and you cannot lift it off, seal is set. Wipe lid and jar surface with a clean, damp cloth to remove food particles and residue. Label. Store jars in a cool, dry, dark place.

Try our Basic Jam Recipe, which includes instructions for making mixed berry jam, peach jam, raspberry jam, and others.

Updated by

Victoria Spencer

Victoria Spencer is an experienced food editor, writer, and recipe developer. She manages the Martha Stewart recipe archive and is always curious about new ingredients and the best techniques. She has been working in food media for over 20 years.

Was this page helpful?

Thanks for your feedback!

Tell us why!