How to Pressure Can (Beginner Guide)
Pressure canning uses a pressure canner to reach the high temperatures that make low-acid foods (vegetables, meats) safe for shelf storage. Always follow a tested USDA or NCHFP recipe for your food, jar size and altitude, exactly. This guide explains the process; recipes provide the safe numbers.
Pressure canning is how you safely put up low-acid foods, vegetables, meats, soups, for the shelf. It is not hard, but it is exacting: the safety comes entirely from following tested procedures precisely.
What you need
- A true pressure canner (not just a pressure cooker), with an accurate gauge, see gauge testing
- Canning jars, new flat lids and bands
- A tested recipe for your specific food
The process in outline
- Prepare jars and food per your tested recipe.
- Fill jars to the specified headspace; remove air bubbles; wipe rims.
- Load the canner with the required water, and vent it to release air before pressurising.
- Process at the exact pressure and time your recipe specifies for your altitude.
- Cool naturally, let pressure fall on its own, then remove jars and check seals.
Each of these steps has details that tested recipes spell out, follow them to the letter.
Which foods need it
Low-acid foods need pressure canning; high-acid foods can use a water-bath canner. See water bath vs pressure canning. New to it? Start with the best pressure canner for beginners.
- National Center for Home Food Preservation (NCHFP) — tested home-preservation methods and the USDA Complete Guide to Home Canning
- USDA Food Safety and Inspection Service (FSIS)
- U.S. Food & Drug Administration (FDA) — Food
- FoodSafety.gov
Frequently asked questions
Why do low-acid foods need pressure canning?
Low-acid foods can harbour Clostridium botulinum spores that survive boiling water. Only the higher temperatures a pressure canner reaches destroy them, which is why a water-bath canner is not safe for these foods.
Can I make up my own canning times?
No. Processing pressure and time must come from tested recipes for your specific food, jar size and altitude. Improvising is a botulism risk.
Do I need to adjust for altitude?
Yes. Higher altitude changes the pressure needed. Tested recipes include altitude adjustments, follow them for where you live.