advance the knowledge and use of Amphoras, as they seem to be able to act as a viable canning method, if mainly for larger stuff. Not sure you could make Amphoras viable at a single person meal size (cold stew?)
Makes sense, since ISTR hearing that Appert's initial proof of concept used champagne bottles as the containers before switching to wide-mouthed glass containers similar to modern mason jars.
While googling to confirm, I came across
this:
He believes that Appert wasn’t working totally from scratch. The idea of preservation by heat was known. There are also historical references to preservation of juice by mild heat treatments, a process now known as “hot filling.” This method was known in Roman times, although the Romans did not have hermetically sealed containers. But Appert could have known of hermetic sealing using water to tighten the lid to the jar for preserving kimchee and sauerkraut in crockery.
And I found
this contradicting the claim that Romans didn't have hermetically sealed containers.
A team of chemists from the University of Valencia (UV) has confirmed that the substance used to hermetically seal an amphora found among remains at Lixus, in Morocco, was pine resin. The scientists also studied the metallic fragments inside the 2,000-year-old vessel, which could be fragments of material used for iron-working.
If accurate, the Romans had all the pieces but just didn't happen to have anyone put them together, probably because the hermetic sealing technique wasn't in widespread use, combined with a lack of theoretical groundwork (such as Spallanzani's work IOTL) that would lead someone to think to try combining heat treatments with hermetic seals.