[resolutebat]

I'm not entirely sure I buy this argument. There are vast swathes of the world today where drinking tap water will likely make you sick, and in all these countries it is standard procedure to boil tap water before drinking it. In fact, in eg China & Indonesia, cold water (even if clean) is believed to be bad for you and drinking still warm boiled water or weak tea instead is very common. Was medieval England really an exception?

[hnlmorg]

You’re comparing England from ~800 years ago to modern day countries. That hardly seems fair.

There’s a lot of knowledge we take for granted that simply hadn’t been discovered yet in medieval times.

[resolutebat]

What, boiling water? The Chinese have been drinking tea for thousands of years.

[dmoy]

Yea but for routine consumption, drinking exclusively hot (boiled previously) water wasn't as much of a thing, especially in Northern China, prior to like mid 1800s.

It was after a particular outbreak (cholera?) somewhere in the 19th century that hit northern China way worse than southern China that they figured out the major difference was the hot water habits in the South. Even in the 1930s there was still a push to increase boiled water usage.

[hnlmorg]

You don’t make tea to kill bacteria. You make it because of the flavour.

[actionfromafar]

Sometimes people do things for a certain reason but it can also have other positive effects. In a way, it doesn’t matter why a trait or behaviour spreads, as long as it’s beneficial.

[hnlmorg]

I don’t disagree with your sentiment but the literal topic of conversation here is the “why” part.

Sometimes conversations can have practical applications. Other times they’re just academic for academics sake. But both are perfectly fine conversations to have.

[resolutebat]

Porque no los dos? And as noted, in China drinking hot water is common, while drinking cold water is (traditionally) frowned on.

[hnlmorg]

Someone has already addressed how that wasn’t for health reasons until relatively recently.

https://news.ycombinator.com/item?id=40418347

[refactor_master]

But humans have been cooking stuff for thousands and thousands of years to improve nutritional value and kill off bacteria. Why would water be an exception?

[hnlmorg]

Bacteria wasn’t known about thousand of years ago. Nor were nutrients (in the sense that we know it now).

There are a plethora of other reasons food might have been cooked, not least of all being flavour. The fact that it also killed bacteria would have been an accidental benefit.

Also a lot of food actually loses nutrients when cooked.

[insane_dreamer]

Ancient cultures relied on observation-based trial-and-error knowledge passed down from generation to generation, mostly involving people dying. They didn't have to understand the causes in order to be correct about the effect. E.g., if you eat raw meat that's been sitting there a while, you get sick and might die. How do we know? Because X and Y people died after eating it. But if you cook it, you don't get sick and don't die. How do we know, because A and B people cooked it and didn't die. Thus -> cook meat. Why? Who knows what unscientific reasons they would give (likely superstitious ones). But "discoveries" of this sort were passed down, in the same way that they discovered which mushrooms not to eat (by people dying when they ate them).

Same applied to which local sources of water were safe to drink (i.e., people didn't die when they drank from there), and whether fermented drink (i.e., beer) was safer than water.

[hnlmorg]

A lot of what our evolved tastes are today actually comes from biological repulsion for stuff that isn’t safe for consumption.

This is why smell was so important.

Unfortunately smell isn’t an accurate gauge for whether a source is safe or not.

[rrr_oh_man]

I think you're underestimating humans who for hundreds of thousands (!) of years have been as smart as you and I.

[hnlmorg]

It’s pretty well documented during the Middle Ages that people thought it was the smell that made them ill and not any bacteria

[neuronerdgirl]

And smell and bacterial levels are absolutely correlated

[kergonath]

Being smart and knowing stuff are not equivalent. The smartest person alive 300 years ago had no clue about bacteria and viruses. Or anything like horizontal gene transfer. Sure, they were not stupid. They still did not know a lot of things, which occasionally made them do stupid things. For example, it is well documented that people believed diseases were transmitted by “bad air” (i.e. pestilence, or bad smells) up until the mid-19th century (not to mention demons). They were not stupid, but there were some things they did not know.

I am not saying that we are any better; there are a lot of things we don’t know that will be taken for granted in 200 years. If there is still a human race.

[Wytwwww]

> For example, it is well documented that people believed diseases were transmitted by “bad air” (i.e. pestilence, or bad smells) up

But that's not particularly stupid. Bad smells are certainly a proxy for diseases to some extent and avoiding them/removing their sources would also decrease the likelihood of getting sick.

[mywittyname]

> Bacteria wasn’t known about thousand of years ago. Nor were nutrients (in the sense that we know it now).

And yet, processed like nixtamalization (the processed used to make the nutrients in maize available to humans) were discovered over 3000 years ago.

If ancient humans figured that complex process out, they certainly would have been able to figure out that boiling water made it safer to drink, even if they didn't know why. They'd probably just claim it killed the evil spirits or pleased the water god and have been happy with that explanation.

If someone is going to go through the process of boiling water, they might as well throw some stuff in there and turn it into soup/tea/broth/stew/whatever so that it tastes nice and makes you less hungry.

[hnlmorg]

Northern China didn’t figure it out until long after the Middle Ages.

https://news.ycombinator.com/item?id=40418347

To accurately gauge if something is safe, you need a quick and direct result that is consistent. Unsafe food and liquid isn’t that. Often it’s more a percentage problem. So to solve the percentage problem you then need a larger sample size. And people simply weren’t organised enough to accurately measure at that scale in the periods you’re suggesting.

As an aside, this is why people got thrown into volcanos and such like. If you don’t have measurements that are easy to correlate then you’re effectively left to guesswork.

[anthk]

Water evaporates and people would think twice before 'losing' it.

[deepsun]

And in all of those places you'd usually noted how bad is the taste of water, so many people knew it's unsafe not just from tradition, but also from the bad taste. The difference between now and medieval England is that we know taste is not everything, that even "sweet water" can be dangerous unboiled.

[thaumasiotes]

> And in all of those places you'd usually noted how bad is the taste of water, so many people knew it's unsafe not just from tradition, but also from the bad taste.

Considering the strength of the Chinese taboo on cold water, I find that fairly unlikely.

[schmidt_fifty]

My understanding is this is rooted in the perception of hot water as a luxury—it's not like we have any shortage of evidence from chinese texts that people have always drank cold water. The idea that most people even could avoid cold water is an artifact of the last two centuries. Even where boiling water was necessary water was boiled and stored (that's not specific to my knowledge of China, that's just an observation from multiple different places and times).

Of course I'm open to be demonstrated wrong.

[kergonath]

We often say that the US are not the world and that we should not assume that something is natural just because American do it. Well, it’s also true for China and overall people in a specific place having a specific taboo tells us very little about human health or their understanding of it.

So no, a Chinese taboo on cold water does not tell us anything about a human tendency to drink water any more that a people’s taboo about pork is any indication that pork is unsafe (yes, this also is an urban legend).

[thaumasiotes]

People in a specific place having a specific taboo can tell us a lot about how likely they are to engage in the tabooed behavior. The argument was that people in China would have noted the bad taste of their raw water. In order to do that, they would have had to drink it, which I find unlikely.