JARSHELF RESOURCES

Tested recipes and process times: where they come from

JarShelf is a record of what you did, not a recipe source. It keeps your batches, jars and seal checks. It never suggests a process time, a pressure, a headspace or an altitude adjustment, and it cannot tell you whether a recipe or a jar is safe. Take those figures from a tested recipe, such as the sources below, and follow them as written. Low-acid foods such as vegetables, meat and beans need a pressure canner; a water bath does not reach the temperature that destroys botulism spores.

The USDA guide and the National Center for Home Food Preservation

• National Center for Home Food Preservation, University of Georgia. The main US source for tested home canning procedures, with recipes for jams, pickles, tomatoes, fruit and pressure-canned vegetables.
• USDA Complete Guide to Home Canning. The reference most tested recipes trace back to, including the process time tables and the altitude adjustments for water bath and pressure canning.
• How do I can? The center's starting page on canning methods, equipment and the basics of jar preparation and headspace.

University extension

• Michigan State University Extension, home food preservation. Fact sheets and tested recipes, plus classes and answers to common questions.
• Utah State University Extension, Preserve the Harvest. Useful if you can at high altitude, where process times and pressures change.

Outside the United States

Few countries publish a national home canning guide of their own. Many canners outside the US follow the USDA guide above. If you can in metric jars, check that the recipe you use was tested for a jar of that size or larger before you rely on its process time.

Honest scope

A good record helps: you can see when a batch was made, what you did, which lids sealed and which jars to use first. It does not make a jar safe. If a seal failed, a lid bulges, the contents spurt, smell wrong or show mould, do not taste it. Follow the disposal advice from the sources above.

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