How do food jar factories put negative pressure into the jar to begin with?
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They just close the jars while it’s hot, cooling down creates the vacuum. You don’t need a factory for that, same thing happens when you make jam or other preserved foods at home.
They just close the jars while it’s hot, cooling down creates the vacuum. You don’t need a factory for that, same thing happens when you make jam or other preserved foods at home.
If it pops it had good seal. Heating content than cooling, thats how you make ajvar last long hehe
If it pops it had good seal. Heating content than cooling, thats how you make ajvar last long hehe
If it pops it had good seal. Heating content than cooling, thats how you make ajvar last long hehe
Canning jars are typically filled as high as possible with liquid and heated. The liquid expands when it gets warmer so it pushes all the air out and the lid is put on while it’s hot. When the liquid cools down it wants to shrink, that’s where the negative pressure comes from. Home canning uses the same basic principle as the cans in the grocery store, if you want to learn more about it there are tons of resources for that.
Canning jars are typically filled as high as possible with liquid and heated. The liquid expands when it gets warmer so it pushes all the air out and the lid is put on while it’s hot. When the liquid cools down it wants to shrink, that’s where the negative pressure comes from. Home canning uses the same basic principle as the cans in the grocery store, if you want to learn more about it there are tons of resources for that.
Canning jars are typically filled as high as possible with liquid and heated. The liquid expands when it gets warmer so it pushes all the air out and the lid is put on while it’s hot. When the liquid cools down it wants to shrink, that’s where the negative pressure comes from. Home canning uses the same basic principle as the cans in the grocery store, if you want to learn more about it there are tons of resources for that.
Old-school canning preserves food by killing every damn thing in there in step one (below) and then creating a low pressure/oxygen environment in step two to make sure nothing that nothing can grown (even though every damn thing is already dead). The current way they do things is still similar-
1. put your old school style mason jars with whatever you want to can/pickle in it in a warm water bath (at least 180 degrees). Let them sit in there a while, and let all those little bastards microbes die a terrible death.
2. Once the fuckers are dead, you put the frisbee looking circle part of the mason jar lid in place, then put the outer ring in place and close it up. The gas in there is hot, and mostly steam.
3. Once everything cools the frisbee will “pop” down, because the hot steamy gas of death in there was higher pressure when hot, but has cooled to a lower pressure than the outside air, and there is a slight vacuumed that results in the pop/sucking down of the frisbee.
The result is something that is very sterilized, and also not a place where new microbes will be able to easily grow if they did manage to somehow get in or survive.
Old-school canning preserves food by killing every damn thing in there in step one (below) and then creating a low pressure/oxygen environment in step two to make sure nothing that nothing can grown (even though every damn thing is already dead). The current way they do things is still similar-
1. put your old school style mason jars with whatever you want to can/pickle in it in a warm water bath (at least 180 degrees). Let them sit in there a while, and let all those little bastards microbes die a terrible death.
2. Once the fuckers are dead, you put the frisbee looking circle part of the mason jar lid in place, then put the outer ring in place and close it up. The gas in there is hot, and mostly steam.
3. Once everything cools the frisbee will “pop” down, because the hot steamy gas of death in there was higher pressure when hot, but has cooled to a lower pressure than the outside air, and there is a slight vacuumed that results in the pop/sucking down of the frisbee.
The result is something that is very sterilized, and also not a place where new microbes will be able to easily grow if they did manage to somehow get in or survive.
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