Not only that, Coke from UK, US, HK, Japan and Mexico taste different as well. Big Bottle 1.5+L taste different to 330ml can, along with Glass Bottled Coke.

And I don't drink them often. May be once every few months or a year.

Note: I never tasted the US version of Pepsi though, so may be they are similar.

Human variance being what it is, I'm sure the result will still be indistinguishable to some people, but I also think there's a lot of people who will suddenly be able to tell the difference quite strongly after this exercise. They're certainly in the same "genre" of drink, but quite substantially different. After this exercise you may also understand why Coke is strongly favored for mixed drink applications. (I mean, to the extent that either is favored. Still, "Rum and Coke" is a thing; "Rum and Pepsi", well, it may get you what you ask for, but you may get a bit of a "look" from the bartender.)

(I was raised fairly typically midwest American, and the injunction to keep your mouth closed while eating was rigorously enforced. I have often wondered if the resulting non-inhalation of the food's volatiles has contributed to the generally poor quality of American cuisine at the time, and its slow progress since then. I've also wondered if "don't inhale your food!", which figuratively means not to eat it too rapidly, also has the literal meaning resonate in our brains and prevent us from doing the good and proper kind of inhalation.)

I presume this is common knowledge on the one hand, but on the other, I've literally never encountered anyone talking about it in a general food context. (YMMV of course.) One of the best kept secrets of "common" knowledge?

But that might be because I rarely drink either.

Even adding animal-based products like bone meal should be fine, since the bones are made out of processed vegetables.