Pressure Canning at Scale: What You Need to Know Before You Buy
The Presto 23 Quart Pressure Canner is basically a bigger version of the standard 16-quart models you see in every grocery store. It's aluminum, stovetop, and does the same job as smaller units — just with more capacity. If you're canning for a family or selling from a home kitchen, the extra volume matters. If you're doing a few jars on the weekend, it's overkill and takes up more counter space. You start by checking the lid gasket ring. These wear out. I had one where the gasket had cracked along the seam and I didn't notice until pressure was building. The valve started hissing in a way that felt wrong, not the steady release you're supposed to get. I let it cool down completely, swapped the gasket, and started over. That's at least two hours you've lost if you're mid-batch. Fill the canner with about two inches of water. Not more, not less. The water level needs to stay above the jars during the process but not so high that it touches the valve mechanism. Place your rack in the bottom, load your prepped jars, and lower the lid into the locked position. Close the vent cock, then put the pressure regulator on top.
Heat it on medium-high until steam pulses steadily out of the vent. That's about ten to fifteen minutes depending on your stove. Once you see a strong, continuous stream of steam for ten full minutes, that's your purge time. This is non-negotiable. You're pushing air out of the canner so the pressure reading is accurate. If you skip this, you're canning at what might be a lower actual temperature than your gauge says, and that's how you get botulism risk in low-acid foods. After the ten-minute purge, close the vent cock and let pressure climb. For quarts, you're looking at 11 pounds of pressure for most vegetables. Pints get ten pounds. Process time starts once you hit that mark and the regulator begins to rock gently. Rock it once every forty-five seconds or so. That's your visual cue that pressure is maintained. If it stops rocking, you turn the heat up slightly. If it's rocking hard and fast, you're over-pressurizing and cooking your food to mush.
Practical Experience and Where People Go Wrong
One thing that trips people up is jar size consistency. The 23-quart canner holds seven quart jars or nine pint jars in a single batch. But if you mix jar sizes in the same run, the smaller jars will overprocess before the larger ones reach temperature. I learned this the hard way when I had a half-full batch because I was short on quart jars. The pints were jammy by the time the quarts were done. Stick to one size per load. Another issue is the weight of this thing. It's heavy when full. Not just the canner itself, but a full load of quarts with water is going to tip the scales at well over a hundred pounds of combined weight. Getting it on and off the stove safely matters more than you'd think. I use a jar lifter with a wide grip and both hands. There's no room for shortcuts there. The dial gauge on these units needs calibration every year. I tested mine against a known-good reference and it was reading two pounds high. That means at 11 pounds on the dial, the actual pressure was closer to 9. If you're canning at 9 instead of 11, your processing time is insufficient for safety. Reset your processing time or fix the gauge. A cheap test is to boil water in a separate pot with a calibrated candy thermometer and compare readings at pressure, though that's less precise than a calibration procedure.
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What This Canner Won't Do For You
This is a stovetop pressure canner. It cannot do vacuum sealing, it cannot automate anything, and it cannot process large batches while you walk away. You're standing at the stove for the entire duration. A 90-minute process means 90 minutes of monitoring. If you need something set-and-forget, look at electric pressure canners, though those have their own issues with capacity and longevity. The aluminum construction heats fast but also cools fast if you move it around. Don't do that. Keep it centered on the burner throughout the entire cycle. Moving it to check something will drop your pressure and reset your timer, effectively. Replacement parts availability is decent since Presto has been making these for decades. Gaskets, rockers, and lids are all easily found. But don't keep using a lid that's been dropped or dented. Even a small deformation in the sealing surface will cause leaks and unsafe pressure readings. I've seen people try to bend a warped lid back into shape. Don't. Replace it.
If you're canning primarily for personal use and rarely exceed four quarts at a time, the 23-quart model is a space hog. A 16-quart does the same job with less water, less heat, and less weight. But if you're regularly processing full batches or running a small preserving operation, the 23-quart Presto is the practical choice and the numbers back it up.
