4 ms·

Nahh, the explanation is there, alright, though nothing supports the "240 degrees" theory (I have to presume they would be Fahrenheit degrees, i.e. 116-120 Cels

by jaclaz 9y ago

Nahh, the explanation is there, alright, though nothing supports the "240 degrees" theory (I have to presume they would be Fahrenheit degrees, i.e. 116-120 Celsius, and of course glass can bear that alright): >The whole industry switched to a new standard for the ripe California olive. "It has to be heated to 240 degrees. And only a can would tolerate that, physically—you couldn’t do that with a glass jar." Eventually, California olives came back. In cans. Even if it was 240 Celsius (which I doubt), glass can bear it just fine.

pyre 9y ago
> of course glass can bear that alright Perhaps not in the 1920s though.
- dpark 9y ago
  Basic glass formulas haven't changed since long before the 1920s. Even borosilicate glass has been around since the late 1800s.
- Symbiote 9y ago
  The setting point of jam is 105°C, so only very slightly cooler. If I remember correctly from making jam with my mother, it's important to pour the really hot jam into the heated jars to ensure everything stays sterile -- so the jam going into the jars is around 105°C.
  - sitharus 9y ago
    That's correct, but I've seen so many recipes on the internet that let the jam cool so the jars don't crack. That's ok for making a small amount to eat quickly, but for proper preservation you really need to do it hot.
    - deleted 9y ago
      [deleted]
    - Symbiote 9y ago
      It helps that my mother trained as a professional cook. That jam kept well for years. I also remember it very clearly, as jam-making was by far the most dangerous cooking we ever did together. I could probably chart my maturity based on how much I was allowed to help, starting from washing the jars and putting them in the oven to sterilize, all the way to doing the whole process while she watched.
VLM 9y ago
Its the jar seal that's the problem. Space age plastics have no problem with 240F, 1920s I donno they had to use wax or natural rubber? Edited to add, and the jar too. The Ball Perfect Mason Jar was introduced in 1913 with a bead for the seal to rest upon. That would have been under patent and expensive in the 20s. So the tech (barely) existed to vacuum seal pressure cooked canned food in the 20s but it would have been patented and too expensive compared to cheaper cans. https://en.wikipedia.org/wiki/Mason_jar https://en.wikipedia.org/wiki/Mason_jar
- virmundi 9y ago
  Just take a second to think about that. 1913. The Romans could not have made such a jar. They lacked the material science. Things like this amaze me. A Ball jar is a simple item from my daily perspective. It is in reality a fairly advanced piece of material science. So if you ever get flung back in time, probably your best best is evaporated sea salt. Then work your way up into simple cosmetics. You don't have the ability to create the supply chain necessary to create canning.
  - lr4444lr 9y ago
    Dunno if the Romans couldn't have made it (their glassware was startlingly good for what we imagine was possible then, if you do a simple image search) but pre-Pasteur, people wouldn't have have conceived of a vacuum seal formed by heat and pressure as a food preservation technique worth pursuing.
    - virmundi 9y ago
      Nor could they have made a rubber for the seal. They didn't have access to the plants (Nazi's tried to use the only source that would have been available at the time to the Romans and failed [1]). Think of the supply chain required to get rubber plants from Asian or the Congo to a Roman city. Carthage would have had a hard time too. Even if they had rubber in enough quantity, they'd have to vulcanize [2] it to make it work. That was years, centuries beyond them. 1 - https://en.wikipedia.org/wiki/Natural_rubber https://en.wikipedia.org/wiki/Natural_rubber 2 - https://en.wikipedia.org/wiki/Vulcanization https://en.wikipedia.org/wiki/Vulcanization Edited for the vulcanization.

by jaclaz 9y ago

pyre 9y ago

> of course glass can bear that alright Perhaps not in the 1920s though.

dpark 9y ago
Basic glass formulas haven't changed since long before the 1920s. Even borosilicate glass has been around since the late 1800s.
Symbiote 9y ago
The setting point of jam is 105°C, so only very slightly cooler. If I remember correctly from making jam with my mother, it's important to pour the really hot jam into the heated jars to ensure everything stays sterile -- so the jam going into the jars is around 105°C.
- sitharus 9y ago
  That's correct, but I've seen so many recipes on the internet that let the jam cool so the jars don't crack. That's ok for making a small amount to eat quickly, but for proper preservation you really need to do it hot.
  - deleted 9y ago
    [deleted]
  - Symbiote 9y ago
    It helps that my mother trained as a professional cook. That jam kept well for years. I also remember it very clearly, as jam-making was by far the most dangerous cooking we ever did together. I could probably chart my maturity based on how much I was allowed to help, starting from washing the jars and putting them in the oven to sterilize, all the way to doing the whole process while she watched.

VLM 9y ago

Its the jar seal that's the problem. Space age plastics have no problem with 240F, 1920s I donno they had to use wax or natural rubber? Edited to add, and the jar too. The Ball Perfect Mason Jar was introduced in 1913 with a bead for the seal to rest upon. That would have been under patent and expensive in the 20s. So the tech (barely) existed to vacuum seal pressure cooked canned food in the 20s but it would have been patented and too expensive compared to cheaper cans. https://en.wikipedia.org/wiki/Mason_jar https://en.wikipedia.org/wiki/Mason_jar

virmundi 9y ago
Just take a second to think about that. 1913. The Romans could not have made such a jar. They lacked the material science. Things like this amaze me. A Ball jar is a simple item from my daily perspective. It is in reality a fairly advanced piece of material science. So if you ever get flung back in time, probably your best best is evaporated sea salt. Then work your way up into simple cosmetics. You don't have the ability to create the supply chain necessary to create canning.
- lr4444lr 9y ago
  Dunno if the Romans couldn't have made it (their glassware was startlingly good for what we imagine was possible then, if you do a simple image search) but pre-Pasteur, people wouldn't have have conceived of a vacuum seal formed by heat and pressure as a food preservation technique worth pursuing.
  - virmundi 9y ago
    Nor could they have made a rubber for the seal. They didn't have access to the plants (Nazi's tried to use the only source that would have been available at the time to the Romans and failed [1]). Think of the supply chain required to get rubber plants from Asian or the Congo to a Roman city. Carthage would have had a hard time too. Even if they had rubber in enough quantity, they'd have to vulcanize [2] it to make it work. That was years, centuries beyond them. 1 - https://en.wikipedia.org/wiki/Natural_rubber https://en.wikipedia.org/wiki/Natural_rubber 2 - https://en.wikipedia.org/wiki/Vulcanization https://en.wikipedia.org/wiki/Vulcanization Edited for the vulcanization.