@NullNowhere what is botulism? sound really bad

@equilibrium@urusai.social It's a form of dangerous food-poisoning that is caused by the bacteria Clostridium botulinum. c. botulinum grows in low-oxygen environments, and it is very hard to kill. It can even survive being boiled.

If you do not can your goods properly, you risk having it contaminated in a way that can cause botulism. Luckily, it's pretty easy to avoid. You ensure that whatever you are canning is high sugar, high acid (pH), or you can it under pressure, which kills the spores.

@NullNowhere thats like, super AMAZING!! clostridium botulinum? sounds super dangerous. it sounds like biohazard. so high pressure kill it? why is that?

@equilibrium@urusai.social when you pressurize water, you raise the boiling point of water. Basically, instead of 100C, the water will boil at temperatures of up to ~120C, which is a temperature that even botulism spores cannot survive.

@NullNowhere ohhh, so botulism is weak to high heat. but hey, i dont know pressure can increase water's boiling point! thats ultra cool! like, that really happen? water boiling point increase to 120°C if you pressure it high? how it work?

@equilibrium@urusai.social I might explain it badly.

Liquids have intermolecular forces that bind them together. The force of the atmosphere as pressure also keeps them together.

So if you heat up water, the molecules gain energy. Heat is just energy. Eventually, they gain enough energy that they begin to escape the attraction of other water molecules and the pressure of the atmosphere. That’s what we call boiling - water is escaping as vapor. As it does so, it takes away excess heat with it, resulting in the remaining water to stay the same temperature - boiling, 100C.

As mentioned, part of keeping the water together is the pressure of the atmosphere - if you lower the pressure of the atmosphere, the water will boil at a lower temperature. If you raise it, it’ll boil at a higher temperature because now it needs more energy to escape and turn into a vapor.

Hopefully that helps

@NullNowhere oh wow, this is like super clear! so water is intermolecular forces. lower pressure cause atoms to split up lower, higher pressure cause atoms to split up higher. wait, did i got it reversed?

wait, i'm dumb. which part of this cause botulis bacteria to die tho?

@equilibrium@urusai.social botulism is heat tolerant, but not heat immune. While it can survive 100C, it can’t survive temperatures beyond that. So the higher heat kills it.

And the easiest way to think about it: higher pressure makes it harder for something to boil, so it has to got hotter before it does.