Food safety for home storage and preserving

Free for everyone. This guidance follows the home food preservation and food safety advice of the USDA and state cooperative extension services, and links to the sources so you can read them yourself.

General information only, based on USDA and extension guidance. It does not replace a tested recipe or your local extension office. When in doubt, throw it out.

Home canning

Use a current, tested recipe from the USDA Complete Guide to Home Canning or the National Center for Home Food Preservation. Do not change the proportions of acid, salt, vinegar or low-acid ingredients.
High-acid foods such as most fruits, jams and properly acidified pickles are processed in a boiling-water canner. Low-acid foods such as plain vegetables, meat and poultry need a pressure canner.
Tomatoes sit near the line between the two, so follow a tested recipe for the acid to add and the processing time.
Process for the time the recipe gives, adjusted for your altitude, and use jars and new lids made for canning.
Open-kettle canning and oven canning are not safe methods.

Checking home-canned food

After cooling, check that each lid is sealed and curved down. Store jars without the screw band, labelled with the date.
Do not use food from a jar with a bulging lid, a broken seal, leaking, spurting liquid, mold or an off smell.
Never taste food to test whether it is safe. Home-canned low-acid food that was not processed correctly can carry the toxin that causes botulism, with no sign you can see.
Extension guidance generally gives about a year as the period for best quality in home-canned food. It is a quality guide, not a guarantee of safety, which is why pantry items marked “Canned on” show a best-by date 12 months later.

Freezing and cold storage

Keep a freezer at 0°F (−18°C) or below and the refrigerator at 40°F (4°C) or below.
Frozen food stays safe indefinitely at 0°F, but quality fades over time, so label packages with the date and use the oldest first.
Thaw in the refrigerator, in cold water or in the microwave, not on the counter.

Dates on packaged food

A “best by” date on a package is generally about quality, not safety. Foods that have been stored properly can often be used past it, but look, smell and handle them carefully.
Perishable foods and anything that looks, smells or feels wrong should be thrown out regardless of the date.
The USDA FoodKeeper is a good reference for how long different foods keep in the pantry, refrigerator and freezer.

Sources

Where this guidance comes from, and where to read more:

Keeping track of dates helps too: the pantry reminds you when something is nearing its date.