Home canning is safe when the process matches the research behind it. It goes wrong when people change the recipe, the jar size, the packing or the method and keep the old time.

What "tested" means here

A tested process is one that a lab has shown to destroy the organisms that matter, for a specific food, jar size, pack style and elevation. The USDA Complete Guide to Home Canning and the NCHFP publish those processes. If a page here gives a time or a pressure, it comes from one of them, and the page says which.

Why we are strict about it

Low-acid foods that are under-processed can grow Clostridium botulinum, the bacterium that causes botulism. You cannot see, smell or taste the toxin reliably, so never taste food to decide whether it is safe. Discard jars with bulging lids, leaks or an off smell without tasting them.

Where to check us

• National Center for Home Food Preservation
• USDA Complete Guide to Home Canning
• Your state land-grant university and county Extension office, who can also test a dial gauge and tell you your elevation.

If you think someone is sick

If anyone has symptoms after eating home-canned food, get medical care right away. In the United States you can also reach Poison Help at 1-800-222-1222.

Poultry and garden pages

We describe what to look for and when a bird or a plant needs a professional. We do not diagnose animals or prescribe treatment. Call a veterinarian for a sick bird.