Tin cans + can opener took a few more years.

The germ theory had not been worked out at this point so he knew it worked but not the mechanism.

Which is to say I believe everyone understood that boiling made things safe or for longer. It would be almost 50 years before people heard of Pasteur’s work with fermentation (and how to stop it).

That segment starts at 16:57 (after development of the Swiss pike, changes in military tactics, mass mobilization in France, leading to the need to feed large mobile armies.)

This being Burke, it's not until 20:40 that it gets to setting up the competition and Appert.

At 24:10 is the transition to talking about tin cans. After discussing a machine to make paper, at 26:06 it leads into the chain of events that resulted in (at 27:49) that French book being translated into English, patented in England, and started (at 28:17) making preserved canned foods - because they were better at metal than bottles.

https://en.wikipedia.org/wiki/Steel_and_tin_cans says the idea was conceived by Philippe de Girard, who got the British merchant Peter Durand to patent the idea in 1810.

https://en.wikipedia.org/wiki/Can_opener adds "the first can openers were not patented until 1855 in England and 1858 in the United States."