Why do soups and teas go bad and unsafe to drink if left out in room temperature for a few hours but it’s perfectly safe to drink a glass of water left out overnight?

Question

Wouldn’t bacteria also grow in the water left out and release toxins?

In: 43

Answer 1

Bacteria needs five things to grow.

Food. Bacteria eat the same things we do.

Temperature. Bacteria like the same temperatures that we do, and grow fastest around 75-95 degrees freedom units.

Water. Bacteria need water to survive. This is why dried rice will stay good forever, but cooked rice grows mold in a day.

Time. Bacteria need time to multiply. The longer something is left out in the above conditions, the more bacteria. And it is exponential. It can go from perfectly fine to eat to making you sick very quickly.

Starting population. Bacteria multiply, but there has to be bacteria in the first place. Every single object humans interact with has bacteria. When we cook food, it kills the vast majority of bacteria. A raw piece of chicken has a lot of bacteria and a high probability of making you sick if you eat it. If you cook the chicken to 165, it kills 99% of the bacteria and suddenly it is safe to eat.

If you leave out cooked chicken, the remaining 1% will start to multiply. There will also be bacteria from the air, the plate it is sitting on, and your hands/utensils you touched it with. There is now a ticking clock on the time before that bacteria multiplies to a large enough population that your immune system gets overwhelmed.

Also to consider, there is some bacteria (and fungus) that doesn’t really harm humans. It’s easy for our immune system to keep in check. Bacteria and fungus in the air are usually pretty mild. Letting a cup of tea sit out *will* get infected… but it’s no big deal. If you drink from it, the bacteria in your mouth will colonize the tea and if it is a sufficient environment with the 5 things above, it will start to multiply. If the environment isn’t very hospitable, such as there being no sugar, it multiplies very slowly.

There is also bacteria that is really really bad. E. Coli is really bad for us and can overwhelm our immune system. This is why we take so much precautions over food that has e. coli, such as chicken.

There are other bacteria that don’t hurt us directly, but leave byproducts that are toxic. This is especially true for meat and grains. Once enough bacteria have reproduced and created their waste, no amount of cooking to kill bacteria is going to matter. The toxins are going to remain.

Now, there are a lot of interesting exceptions. But that’s beyond the scope.