Home canning preserves food only when the processing method is appropriate for the food, jar size, pack style and altitude. This is an introduction to choosing a safe method, not a processing recipe.
Choose a tested recipe first
Use a current recipe from the USDA, the National Center for Home Food Preservation, or a university extension service. Follow its ingredient proportions, preparation, jar size, headspace, processing time and altitude adjustment exactly. Do not adapt an ordinary soup, sauce or family recipe for shelf storage without a validated process.
Water-bath or pressure canning?
Boiling-water canning is appropriate for foods that have sufficient acidity under a tested recipe. Low-acid vegetables, meat, poultry and fish require a pressure canner. Some foods, including tomatoes, need specified added acid even when they taste acidic. A boiling-water bath does not substitute for a pressure canner, and a pressure cooker or electric multicooker is not automatically a suitable pressure canner.
Process, cool and check
- Inspect jars and use lids and equipment as directed by their manufacturers and the tested recipe. Keep jars hot when required.
- Fill with the specified pack and headspace, clean rims and apply lids as directed. The final vacuum seal develops during processing and cooling; tightening a lid does not make food safe.
- Use the exact time and pressure for your altitude. For pressure canning, vent steam for 10 minutes before pressurizing and follow instructions for pressure loss, cooling and opening.
- Let jars cool undisturbed as directed, check seals, remove screw bands for storage, label and date. Follow the tested guidance for an unsealed jar; do not simply put it on the shelf.
Store correctly processed jars in a cool, dark, dry location and aim to use them within one year for best quality. Discard leaking, bulging or otherwise suspect jars according to official instructions; never taste food to decide whether it is safe. A normal appearance or a sealed lid cannot prove a jar is safe.
Start with the complete instructions linked below and a tested recipe for the exact food you plan to preserve.
Sources and further reading
Editorial update: October 23, 2026. Updated for clarity, completeness and the corrections noted in the linked sources, where supplied.
