Pressure Canning: How to Can Green Beans, Corn and Meat Safely

Updated October 2026

Low-acid foods need a pressure canner and a tested USDA process, adjusted for your elevation. Here is what that means at the stove.

Green beans, corn, carrots, potatoes, squash, meat, poultry, fish and stock are low-acid foods, and a pressure canner is the only safe way to can them at home. A boiling water bath cannot get them hot enough, however long you run it. Use a current USDA or extension recipe, set the pressure for your elevation, and do not shorten any step below.

Why a water bath fails low-acid food

Clostridium botulinum spores survive boiling. In a sealed jar with little acid and no air they can grow and produce botulinum toxin, which you cannot see, smell or taste. The spores are destroyed at 240°F held for the tested time, and a home kitchen only reaches 240°F under pressure. Food with a pH of 4.6 or lower (fruit, acidified tomatoes, vinegar pickles) can go in a boiling water canner. Everything above pH 4.6 needs pressure.

Plain tomatoes sit close to the line. USDA requires bottled lemon juice or citric acid in every jar of tomatoes, even when you pressure can them.

Choosing a pressure canner

• Size: USDA processes assume a canner that holds at least four quart jars. Smaller pressure cookers heat and cool too fast for the tested times.
• Electric multicookers: not for canning. The National Center for Home Food Preservation does not support USDA processes in them, even models with a canning button.
• Weighted or dial gauge: a weighted gauge jiggles or rocks at a fixed pressure and never needs testing. A dial gauge lets you set any pressure but drifts, so have it checked every year; many county extension offices test them. Replace a dial that reads more than 2 pounds high or low.
• Burner: check your canner's manual. NCHFP warns against outdoor LP burners and gas burners over 12,000 BTU, which can damage a canner.
• Jars and lids: Mason jars with two-piece lids (Ball and Kerr). Use a new flat lid every time; bands can be reused. Mayonnaise jars break too often under pressure.

Step by step

1. Start from a tested recipe from USDA, NCHFP or your state extension service, and follow its jar size, pack style and headspace.
2. Put the rack and 2 to 3 inches of hot water in the canner, or more if the recipe says so.
3. Load the filled jars, fasten the lid, and leave the weight off or the petcock open.
4. Heat on high until steam flows in a steady funnel from the vent. Vent for 10 minutes.
5. Put the weight on or close the petcock. The canner pressurizes over the next 3 to 10 minutes.
6. Start timing when the dial shows the target pressure, or when the weighted gauge jiggles or rocks as its manual describes.
7. Keep the pressure at or slightly above the target. If it drops below at any point, bring it back up and restart the full process time.
8. Turn off the heat and let the canner depressurize on its own. Do not cool it with water or lift the weight early.
9. Once it reads zero, remove the weight, wait 10 minutes, then lift the lid away from your face.
10. Set jars on a towel 1 inch apart and leave them 12 to 24 hours before checking seals.

Pressure by elevation

Above 1,000 feet, water boils at a lower temperature, so you raise the pressure; the time does not change. Denver sits at about 5,280 feet, and much of the Mountain West is higher still. If you are not sure of your elevation, look it up for your address before you start.

These are the USDA pressures for most vegetables, including snap beans. A few products differ, so always read the table for the food in your canner.

Two examples from the USDA guide

• Snap beans, hot or raw pack, 1-inch headspace: pints 20 minutes, quarts 25 minutes. USDA lists no safe boiling water option.
• Pumpkin and winter squash, 1-inch cubes boiled 2 minutes: pints 55 minutes, quarts 90 minutes. Do not mash or puree squash for canning; freeze puree and pumpkin butter instead.

Half-pint and pint jars share a time, as do 1½-pint and quart jars. There are no tested low-acid times for half-gallon jars.

Storage and spoiled jars

Remove the bands, wipe the jars, label and date them, and store them between 50 and 70°F, never above 95°F or near a furnace, range or hot pipes. Use them within a year. Do not taste food from a jar with a bulging or unsealed lid, spurting liquid, an off smell or mold. Bag a sealed suspect jar and put it in the trash; if it is leaking or open, wear gloves and follow the USDA detoxification and bleach clean-up steps.

Call 911 if anyone has trouble breathing or swallowing after eating home-canned food. Poison Control is 1-800-222-1222.

See also: The four ways to preserve, Canning tomato sauce for the water bath method, and Pickling.

Sources we checked (October 2026): USDA Complete Guide to Home Canning (2015) through the National Center for Home Food Preservation: Using Pressure Canners, Recommended Jars and Lids, Equipment and Methods Not Recommended, Snap Beans, Pumpkins and Winter Squash, Storing Home Canned Foods, Identifying and Handling Spoiled Canned Food; NCHFP, Can I Can in a Multi-Cooker?.

Common questions