FR

Pressure Canning

The only safe home method for low-acid foods: vegetables, meats, poultry, fish, beans, and soup. A boiling-water bath cannot reach the temperature needed to kill Clostridium botulinum spores in low-acid foods.

How it works

Pressure canning reaches about 116 °C — high enough to destroy botulism spores. A water-bath at 100 °C cannot. Skipping or shortcutting pressure canning on a low-acid food can be fatal.

When to use this method

Use pressure canning for: green and yellow beans, corn, peas, carrots, beets, mixed vegetables, meats, poultry, fish, broth and stock, dried beans, and low-acid soups (no thickeners or dairy).

Authority sources

How pressure canning preserves food (and why water-bath can't)

Every canned food carries a microbiological risk, and one organism above all sets the rules: Clostridium botulinum. Its spores live everywhere — in soil, on vegetables, on raw meat — and they survive boiling water indefinitely. In a sealed, low-oxygen, low-acid jar at room temperature, those spores germinate, multiply, and produce botulinum toxin. Public Health Ontario's 2014 home-canning review sets out the conditions that let it happen, and publishes no dose. HealthLink BC's File #22 does publish a potency statement. This page carries neither figure: the superlative it used to carry was ours rather than anyone's, and how potent the toxin is changes nothing about what you do.

The only home-kitchen method that destroys C. botulinum spores is heat above 116 °C (240 °F), held for the full processing time of a tested recipe. Water at sea level boils at 100 °C and goes no higher no matter how hard the burner runs — that's why a boiling-water bath cannot make low-acid food safe. Steam under pressure does reach 116 °C, and a pressure canner is the only home appliance built and tested to hold that temperature accurately for an hour or more.

The line between "water-bath safe" and "must be pressure canned" is the food's natural pH. Below 4.6 (fruit, jam, vinegar pickles, properly acidified tomatoes) the acid itself blocks spore growth — water-bath works. At or above 4.6 (every vegetable, every meat, every bean, every plain broth, plain pumpkin) only pressure canning is safe. There is no edition of Grandma's recipe and no quantity of added lemon juice that turns a low-acid food into a water-bath candidate. See the pH rule, in full, and the Public Health Agency of Canada's botulism backgrounder for the public-health side.

Pressure canner ≠ pressure cooker

A pressure canner and a pressure cooker, compared A line drawing of two vessels side by side. The pressure canner is the taller: it carries a dial gauge and a vent pipe with a weighted regulator on its lid, three jars stand upright on a rack inside it, and the water sits shallow around the base of the jars rather than over them. The pressure cooker is short enough that its whole lid falls at about the height of the canner’s jar tops; it has a small pressure indicator pin in place of a dial, a sealing valve in place of an open vent pipe, and a small trivet in place of a canning rack. Pressure canner 1 2 3 4 Pressure cooker 1 2 3 4

This diagram shows the equipment, not the method. It is here to help you tell a pressure canner from a pressure cooker. Water depth, processing times and pressures come from your tested recipe and your canner’s manual — not from this drawing.

  1. 1. The gauge. A canner has to reach and hold a stated pressure, so it carries a dial that measures the internal pressure, a weighted regulator that jiggles at 5, 10 or 15 lb, or both. Bernardin publishes a separate altitude table for each type, so the gauge you own decides which table you follow. Drawn on the cooker: a pressure indicator pin, which tells you the vessel is under pressure and not what pressure it is at.
  2. 2. The vent pipe. Left open at the start, with steam exhausted through it for 10 minutes before the pressure is brought up. That purges the air which would otherwise lower the temperature the jars actually reach. Drawn on the cooker: a sealing valve, which closes the vessel rather than venting it.
  3. 3. The rack. A canning rack holds the jars off the base so water circulates underneath them and the glass never sits on direct heat. Drawn on the cooker: a trivet, which is there to lift food clear of the liquid.
  4. 4. The size. A canner is built around the jar — tall enough that filled jars stand upright with the lid locked, and wide enough to hold a batch of them. The dashed line marks where the drawn cooker’s rim falls against that.

A cooker may share some of these parts, and that is the trap. The reason it is not a substitute is not the hardware. Bernardin’s published position is that heat processing high-acid foods in a boiling water canner and low-acid foods in a pressure canner are the only currently approved methods for safe home canning — and their tested processing times were established in those two vessels. There is no tested time to apply to any other appliance.

This is the most important equipment distinction in home preserving. A pressure canner is purpose-built for the task: it holds 7 × 1 L jars or 16 × 500 mL jars upright on a rack, reaches and holds the high pressures needed to destroy botulism spores, and has a regulator (weight or dial) calibrated for canning.

A pressure cooker — including the Instant Pot — is not a pressure canner, and the reason is not the hardware. Bernardin's published position is that heat processing high-acid foods in a boiling water canner and low-acid foods in a pressure canner are the only currently approved methods for safe home canning. A cooker is neither, so none of Bernardin's tested processing times were established in one and there is no tested time to apply to it. Some Instant Pot models advertise a "canning" function; that does not put a tested time behind it. Treat the canner and the cooker as two separate purchases. The methods Bernardin says not to use covers the electric-multicooker question in full, and our Presto vs All American buying guide walks through the two genuine pressure canners worth owning in Canada.

Equipment you need

  • A genuine pressure canner — common Canadian-available models are Presto (23-quart or 16-quart) and All American (cast aluminum, weighted gauge, lifetime warranty). 23-quart canners hold a full case of 500 mL jars in one batch.
  • Dial gauge or weighted gauge? Weighted-gauge canners hiss when the pressure is right, and a weight sits at fixed pressures so it cannot drift the way a dial can — there is no yearly recalibration step. Dial-gauge canners give a more precise reading. HealthLink BC publishes that both weighted gauges and dial gauges should be checked for accuracy, following the directions from your canner manufacturer for the test and how often to run it — so a weight is one less thing to recalibrate, not one less thing to check. We name no place in Canada to get a dial gauge tested, because no Canadian authority we could find publishes one — see weighted gauge against dial gauge.
  • Bernardin jars — most pressure recipes use 500 mL or 1 L. Verify the recipe specifies your jar size; pressure times depend on it. Wide-mouth jars make packing chicken pieces, fish chunks, and stew much easier — see wide-mouth vs regular-mouth.
  • Fresh SNAP lids for every batch — same single-use rule as water-bath. See SNAP lid reuse rules.
  • Jar lifter, headspace tool, funnel — same as water-bath canning.
  • A timer with an alarm. Pressure-canning times in the recipes behind this site run from 20 minutes (500 mL of strained broth) to 100 (salmon); do not eyeball it.

See the Canadian canning equipment guides for canner, jar, and tool comparisons in Canadian sizes and prices.

What to pressure can

Every food on this list is low-acid and unsafe for water-bath canning. Pressure canning is the only safe home method.

  • Plain meats — chicken (raw-pack or hot-pack), beef, pork, ground meat, game.
  • Stew and soup — beef stew without thickener, chunky vegetable soup. The no-thickener rule (no flour, cornstarch, pasta, or rice) is universal — thickeners block heat penetration and make the process unsafe.
  • Stocks and broths — bone broth (chicken or beef). Strained clear broths process faster than chunky soups. Bernardin publishes no fish stock, so we hold no tested time for one.
  • Fish and shellfish — pressure-canned salmon. Three tested recipes exist, and each carries its own scope rather than covering seafood generally. Bernardin's Complete Book Fish recipe (p.396) says it works for all varieties of fish, including salmon and shad, with the exception of tuna: it soaks the fish in a salt-water brine, packs it into unheated jars, and gives 100 minutes for both jar sizes — longer than any meat on this list. Tuna is excluded from that recipe and has its own on bernardin.ca, raw pack or hot pack, also at 100 minutes. Clams (p.397) are the only shellfish either source publishes: 60 minutes for 250 mL jars, 70 minutes for 500 mL, and Bernardin states that pressure canning is the only safe method for them. We hold nothing at all for shrimp, crab, lobster, oysters, mussels or scallops. Every one of these is 250 mL or 500 mL only — Bernardin rules out 1 L for fish and seafood outright.
  • Dried beans — navy, kidney, pinto, black, romano, all Canadian-grown varieties. A jar costs a fraction of a commercial can.
  • Plain vegetables — green beans, corn, peas, carrots, beets (without vinegar), mixed vegetables.
  • Plain pumpkin or winter squash — cubes only — never puree. Puree is too dense for safe heat penetration; Bernardin specifies cube-pack as the only safe form.

Corrected 16 September 2026: this list used to name trout, char, tuna and shellfish alongside salmon, and split salmon into "Pacific or Atlantic". We held no tested processing time for any of those four — the one tested fish recipe behind this site was salmon — and the Pacific/Atlantic split was our own wording, not a distinction the recipe makes. If you pressure-canned trout, char, tuna or shellfish on the strength of the earlier version, we cannot tell you it was processed for a time anyone tested; do not eat or taste them. Discard those jars, following the disposal steps in the discard checklist. Amended 17 September 2026: tested recipes are published now — Bernardin's Complete Book Fish (p.396) and Clams (p.397), and their tuna recipe on bernardin.ca. They were not on this page when those jars were filled, and nobody can know after the fact whether a jar matched one of them on pack, jar size and brine.

The pressure-canning process at a high level

  1. Read the tested recipe in full. Verify jar size, headspace, and processing time. Pressure canning has zero room for improvisation.
  2. Prep food and pack jars. Hot-pack is standard for most low-acid foods. Follow the recipe's headspace exactly.
  3. Apply fresh SNAP lids and bands fingertip-tight.
  4. Add 5–7 cm of water to the canner (per the canner's manual — not enough to cover the jars; you want steam, not a water bath).
  5. Vent the canner. Lock the lid, heat on high. Let steam exhaust through the open vent for a full 10 minutes — this purges air, which would otherwise lower the internal temperature and make the process unsafe. Do not skip this step.
  6. Apply the regulator (the weight or the dial gauge cover). The canner will pressurize.
  7. Reach and hold pressure. Once the gauge reads the recipe's required pressure (typically 10 lb or 15 lb depending on altitude — see below), start the timer. Adjust heat to maintain pressure; if it drops, you must restart the timer once it returns.
  8. Process for the full recipe time. Do not lower the pressure to "save time."
  9. Cool naturally. Turn off heat, leave the canner closed and the regulator in place until the pressure returns to zero on its own. Never force-cool a pressure canner — sudden depressurization breaks seals and can crack jars violently.
  10. Remove jars, leave them undisturbed 24 hours, then check seals.

Altitude: change the pressure, not the time

For water-bath canning, altitude adds minutes. For pressure canning, altitude raises the pressure.

Bernardin's rule is:

  • Dial-gauge canners: a defined PSI step per altitude band. Below 305 m typically 11 lb; above, increases per band.
  • Weighted-gauge canners: two settings (typically 10 lb and 15 lb). Below 305 m use the lower setting; above, switch to 15 lb.

The processing time stays the same. Open your Bernardin edition for the exact PSI table — do not use US numbers, because Canadian elevation cut-offs differ. The Canadian altitude-adjustments guide lists every Canadian city and its band.

Shelf life of pressure-canned food

Bernardin recommends consuming home pressure-canned food within one year for best quality. That is a quality window rather than an expiry: the food is as safe as the process made it, and colour, texture, and flavour all degrade past 12 months. Bernardin publishes the one-year window and no second threshold beyond it, so neither do we.

Storage rules:

  • Cool, dark, dry — pantry or basement shelf. Not above the stove, not in a freezing unheated garage.
  • Remove the bands after the seal sets. Bands trap moisture against the lid edge and can mask a failed seal.
  • Label every jar with the date and contents. By February you will not remember which jar of broth is chicken and which is beef.
  • Inspect before opening. Bulging lid, off smell, mould, discolouration, or a hissing release of pressure all mean discard. The full discard checklist.

See our full shelf-life guide for category-by-category breakdowns.

Common failures

  • Skipping the vent. The 10-minute steam vent purges air from the canner. If air is left inside, the canner reads "pressure" without reaching the temperature that makes pressure canning safe. This is the most dangerous shortcut in low-acid canning.
  • Out-of-calibration dial gauge. If your gauge reads 11 lb but the canner is actually at 8 lb, the contents do not reach the temperature that kills botulism spores. Check it as often as the directions from your canner manufacturer say — that is HealthLink BC’s instruction.
  • Pressure drops during processing. The recipe assumes steady pressure. If it drops below the target, the timer restarts. Don't be tempted to "make up the time" by adding to the back end — restart fully when pressure returns.
  • Force-cooling. Cracking the lid or running cold water on the canner to speed cooling is dangerous and ruins seals.
  • Adding thickeners. Flour, cornstarch, pasta, rice, or dairy in a pressure recipe block heat penetration. Thicken in the pot when you reheat — never in the jar.
  • Using untested recipes. Mixed recipes (chili, spaghetti sauce with meat, soup with thickener) require a Bernardin-tested formulation, not a Pinterest one. The pH rule, explained.

First-time pressure canner FAQ

Is a pressure canner loud? Yes. A weighted-gauge canner jiggles audibly — that's its way of telling you the pressure is right. A dial-gauge canner is quieter but still hisses steam. Plan for a kitchen that sounds like a small steam engine for 60–90 minutes.

Can I run a smaller batch than the canner holds? Yes. Maintain the minimum water level the manual specifies (typically 5–7 cm); you can process as few as two jars in a 23-quart canner as long as they're upright on the rack.

Can I leave the canner unattended? No. You need to be in the kitchen the entire processing time to adjust heat if pressure drops or climbs. Pressure canning is not a set-and-forget appliance.

Why does the recipe specify 1 L jars only? Heat penetration depends on jar dimensions. A jar size not listed in the recipe has not been tested at that time and pressure — using a different size is improvising on safety.

What if I lose pressure for 30 seconds during processing? Re-establish pressure and restart the timer from zero. Adding "the missing 30 seconds" to the end does not work — heat penetration depends on continuous time at temperature.

Can I pressure can in glass-top stoves? Check both the canner manufacturer and the stove manufacturer. Some glass-top stoves restrict the weight or footprint a burner can support; some pressure canners have flat enough bottoms to qualify, others don't. Manufacturers publish lists.

When to use pressure canning vs alternatives

  • Pressure-can when you want shelf-stable low-acid food: green beans, corn, plain meat, broth, dried beans, vegetable soup (no thickener), Bernardin's pressure-tested meat sauces.
  • Acidify and water-bath only when a tested Bernardin recipe specifies the exact acidification (lemon juice, vinegar, citric acid) and processing time. Pickles, salsa, pizza sauce, and acidified tomatoes fit here. See the water-bath canning pillar.

Every guide in this method

Sources