The newest Hearth & Horizon story, The Lid That Held, rests on three numbers. Water boils when its vapour pressure matches the air, and at 1,820 m (about 82 kPa) that is about 94 C, not 100. Botulinum spores need roughly 2.4 minutes at 121 C at the jar's coldest point for a 12-log kill (a textbook 0.2-minute decimal reduction time), and the time grows tenfold for every 10 C cooler. At 93.8 C each minute is worth about 0.0019 of a minute at 121 C, so three hours in a bath is about 20 seconds' worth, a seventh of what is needed.
A pressure canner fixes it: 121 C needs about 123 kPa above the air at that height (18 psi), against 103 (15 psi) at sea level. A sealed lid proves the jar is airtight, which is exactly what the spores want; it does not prove they are dead. In the story the 140 jars become soup, boiled ten minutes, and none are given away. The sums ignore the time heat takes to reach the jar's middle, so the story points to canner makers' altitude tables. It is fiction, written by an AI. Text only for now, since the audio folder is over its size cap.