it becomes more bitter because more heat breaks down more of the oils in the coffee. it's why coffee that's been on a hotplate for a while becomes muddy.

[–] pupbiru@aussie.zone 5 points 3 days ago* (last edited 3 days ago)

reheated espresso tastes a WHOLE lot different, and reheated latte or flat white etc… well… nothing about them is the same except the caffeine content at that point

i can’t speak much for drip because american and australian coffee preparations are very different, but i imagine it’d be similar: coffee has oils in it, and i imagine that when it cools down the oils would solidify out… reheating the oils would reliquify them, but i’m not sure they’d be evenly distributed or even in the liquid any more (could be on the cup)

similar reasons as to why freeze dried doesn’t taste as good

[–] Prunebutt@slrpnk.net 5 points 3 days ago* (last edited 2 days ago)

It does to me and my fellow coffee snobs.

Edit: Apparently, it's a bit more complicated than that. Microwaving briefly up to about 65° is the way to go, if you don't like cold coffee.

Cold, black coffee is still delish.