Pressure cooker altitude adjustment: how much longer to cook at elevation

A pressure cooker's dial or valve reports gauge pressure, meaning pressure added on top of whatever the surrounding air pressure already is, not an absolute number. At sea level, atmospheric pressure is close to 14.7 psi, so an electric cooker running at roughly 11 psi of gauge pressure sits at close to 25.7 psi absolute. At 5,000 feet, atmospheric pressure has already dropped to around 12.2 psi, so the same 11 psi gauge reading only reaches about 23.2 psi absolute, a lower total pressure that boils water at a lower temperature. The cooker is not doing anything differently; the air around it is thinner, and the math of gauge pressure means the pot never fully compensates on its own.

Add 5 percent to the recipe's time for every 1,000 feet above 2,000 feet. Below 2,000 feet, no adjustment is needed at all. The table below applies that rule to a 20 minute recipe as a worked example; scale the same percentage against whatever time your specific recipe calls for.

The percentage stays the same, but the actual added minutes scale with the base recipe's length. A 20 minute recipe at 5,000 feet gains about 3 minutes, which is easy to round away and forget about. A 75 minute chuck roast, like the kind covered in the beef chuck roast pressure cook time entry, gains over 11 minutes at the same 15 percent, which is enough to matter if you are planning dinner around it. Longer cooks feel the adjustment more in absolute minutes even though the percentage applied is identical.

No, and this is worth stating plainly rather than assuming the same 5 percent rule carries over. Pressure canning at altitude uses its own set of validated pressures and times specific to the food being canned, the jar size, and the elevation, developed to guarantee a safe internal temperature throughout a sealed jar. Those figures come from USDA or the National Center for Home Food Preservation, not from the arithmetic on this page, which only applies to cooking dinner in an open pot under pressure. Do not substitute this altitude adjustment for a canner's own altitude chart.

No. A quick release still drops pressure suddenly and is still the right call for vegetables that would overcook during a slower release, and a natural release still lets pressure fall gradually and is still the right call for beans, pulses and large cuts of meat that would split or seize under a sudden pressure change. Thinner ambient air can make a natural release look or sound slightly different, since there is less atmospheric pressure resisting the pot's internal pressure as it falls, but it does not change which method is correct for which food.

A stovetop cooker's true 15 psi still cooks faster than an electric cooker's roughly 11 psi even after both get the same altitude adjustment applied, so the roughly 20 percent time savings a stovetop unit offers at sea level carries over at elevation as well. A machine like the Presto 6 qt or the T-fal Clipso run on a strong burner can partially offset the altitude penalty compared with a lower pressure electric cooker like the Instant Pot Duo, though neither escapes the altitude adjustment itself; the two effects, cooker type and elevation, stack rather than cancel out.