Pressure canning

This is the purchase people put off, and mostly they are right to. A first harvest of fruit and pickles does not need one. The moment it does need one is the moment somebody offers you a bushel of green beans, or you decide to can chicken stock, or you want plain tomatoes without adding lemon juice. Then there is no substitute and no workaround.

What a pressure canner is not

It is not a pressure cooker, and the distinction is not pedantry. The NCHFP states plainly that "pressure saucepans with smaller volume capacities are not recommended for use in canning." A canner has to be big enough to hold seven quart jars or eight to nine pints, because tested processing times assume a mass of jars and water that heats and cools at a particular rate. A small pot cools far too fast, and the tested time no longer means what it says.

The same caution applies to electric multi-cookers. A "canning" button on an appliance is a marketing label unless the manufacturer specifically states the model is validated for pressure canning. A small number are — Presto states its Precise digital canner meets USDA guidelines for low-acid foods — and the overwhelming majority are not. We take that apart in electric pressure canners.

Dial gauge or weighted gauge

This is the one real fork in the decision. A dial gauge shows you a needle and a number, which lets you hit an exact pressure — useful at altitude, where the required pressure changes. The catch is that dial gauges drift and should be tested for accuracy every year, usually free at a county extension office. Most owners never do it, which turns a precision instrument into a guess.

A weighted gauge has no needle. A machined weight sits on the vent and rocks when the pressure is right, in fixed steps of 5, 10 and 15 psi. There is nothing to calibrate, ever. The trade is that at altitude you round up to the next weight rather than dialing an exact figure, which is slightly less efficient and no less safe. For a first pressure canner with no extension office nearby, weighted is the lower-maintenance answer.

The stove problem is worse here

Pressure canners are heavier and often wider than water bath canners, and the cast-aluminum ones are considerably wider. The All American 921 publishes a bottom exterior diameter of 15 3/8 inches, which under the NCHFP's 4-inch rule needs an element of at least 11 3/8 inches — larger than almost any household electric element. That is not a defect in the canner; it is a mismatch with a stove, and it is entirely predictable before you buy. Run your own numbers on will it fit your stove.

Where to start

Read what foods need pressure canning first, so you know whether you need one at all this year. If you do, best pressure canners is the roundup, and All American vs Presto is the comparison almost everyone ends up making.