It's safe to say the Instant Pot is the hottest kitchen gadget—at least in the United States—in the past five years. The company is capitalizing on that success by rolling out new and better models, including the Instant Pot Max slated for later this year.
The Instant Pot Max promises a number of overdue upgrades (particularly to the user interface), but Instant Pot is also touting a brand-new feature: the ability to be used for pressure canning.
Canning is the process by which home cooks can seal their homemade sauces, jams, fruits, meats, and vegetables so that they can be preserved for significantly longer than usual. There are typically two type of devices for canning foods at home: boiling canners and pressure canners.
Boiling canners use boiling water to kill off most bacteria, but there's one nasty one they can't kill off: Clostridium botulinum, aka the cause of botulism. Acidic foods naturally prevent the growth of botulism, so highly acidic foods are usually fine with a boiling canner when processed correctly. For low-acid foods like vegetables, meat, and tomatoes, you need a pressure canner.
As the USDA states in its Complete Guide to Home Canning, pressure alone does not kill bacteria. But because pressure canners can get up to 15PSI, the steam inside will reach over 240°F, the temperature required to kill the bacteria that causes botulism. (Boiling water canners top out at 212°F)
The new Instant Pot Max claims it can reach 15 PSI consistently, but that isn't enough to guarantee your food is being heated to the point where it will be safe. CNET recently dug into the issue as well, and found that Instant Pot's own website claims that its models shouldn't be used for pressure canning.
The main reason is that a pressure gauge doesn't tell you what the temperature is, and if there is air trapped inside or you're at altitude the 15 PSI setting may not reach the necessary temperatures to work. Because the Instant Pot doesn't have an internal thermometer (that we know of), it's just not possible to tell exactly how hot it is inside and when your food will be safe.
Instant Pot may be able to sort through these issues once the Max launches later this spring, but for the time being it's a good idea to just avoid using the Max's pressure canning feature until it has been thoroughly tested and proven safe by the manufacturer and outside groups.
In the meantime, you can still use your Instant Pot for nearly everything else, including boiling water canning—just make sure you follow all the appropriate guidelines and use acidic foods to makes sure what you're serving is safe to eat.