preserve · Preserve

How to Water Bath Can for Beginners

Water bath canning uses boiling water to preserve high-acid foods like jams, pickles, and tomatoes in sealed jars. You submerge filled jars in a large pot of boiling water for a specific time, creating a vacuum seal that keeps food safe for months. Only high-acid foods (pH 4.6 or lower) are safe for water bath canning.

Step by step

  1. Gather your equipment. You need a large pot with a lid (tall enough for jars plus 2 inches of water above them), canning jars with new lids and rings, a jar lifter or tongs, and a ladle. A canning rack helps but you can use a folded kitchen towel in the pot bottom.
  2. Prepare your jars and lids. Wash jars in hot soapy water. Keep them hot by leaving in the dishwasher after a cycle or submerging in hot water. Place new lids in a small pot of hot (not boiling) water. Never reuse lids.
  3. Fill your canning pot. Fill the pot halfway with water and bring to a simmer. Place your rack or folded towel on the bottom. The water should cover your jars by 1-2 inches when they're added.
  4. Fill the jars. Ladle hot food into hot jars, leaving the headspace specified in your recipe (usually 1/4 to 1/2 inch). Wipe jar rims clean with a damp cloth. Any food residue prevents proper sealing.
  5. Apply lids and rings. Place a hot lid on each jar. Screw on the ring finger-tight only. Too tight prevents air from escaping during processing.
  6. Process the jars. Lower jars into the boiling water using your jar lifter. Water must cover jars by 1-2 inches. Return to a rolling boil and start your timer. Process for the exact time your recipe specifies.
  7. Cool and check seals. Remove jars and place on a towel-lined counter. Don't disturb for 12-24 hours. You'll hear the lids pop as they seal. After cooling, press the center of each lid. Sealed lids won't move. Store unsealed jars in the refrigerator.

Tips & troubleshooting

Variations

Questions

What foods can I water bath can?
Only high-acid foods like most fruits, jams, jellies, pickles, and tomatoes with added acid. Low-acid foods like vegetables, meat, and plain tomatoes need pressure canning.
Can I use any jar for canning?
No. Use only mason jars designed for canning. Mayonnaise jars and other food jars aren't made to withstand the heat and pressure of canning.
Why didn't my jars seal?
Common causes include food residue on the jar rim, overtightened rings, old or damaged lids, insufficient processing time, or fluctuating water temperature during processing.
How long do home-canned foods last?
Properly canned high-acid foods stay safe indefinitely but quality degrades over time. Use within 18 months for best flavor and texture.
Can I double canning recipes?
You can double the ingredients but process in the same size batches. Large batches heat unevenly and may not preserve safely.

Further reading