I’m not Indian, but my friend shared me a post, The forgotten caste history of an everyday practice: Drinking Filter Coffee, and it took some explanation to realize that the main question at hand has nothing to do with coffee, but the way of drinking.

It’s explained to me that Indians drink water by pouring liquid (like water) from cup directly to their open mouth, rather than sipping on the cup. Their cups are usually shared, and for purity rules (and I guess nowadays hygiene), everyone drink with open mouth.

The comments in the blog post are people either arguing about the drinking method is casteism to not share saliva with lower caste, which I guess could be true, or as with everything, kinda vague? My friend doesn’t really think that much because it’s what everyone does. And there are many “purity rules” or I call it spiritual clean-freak.

But specific to the drinking water out of a cup with open mouth, especially with high priest doing it too, see Why dont they touch their lips to the cup?, how much of it is actually casteism? What’s the history of it like? Because many cultures around the world don’t do the same thing even when sharing cups (not to the same extent, it’s perfectly fine where I grew up to just use different edges, and while some people may drink with open mouth, it’s not a “rule”).