#LIFEHACK:
Acids are spicy/sour
Bases(aka alkaline iykwim) are bitter
YWIA
what about coffee
I would guess the bitterness comes from the caffeine, which is a methylxanthine alkaloid
ok but the liquid known as coffee is acidic and tastes bitter. 
Mocat my dude, there are few hard and fast absolutes, there’s almost always an exception to the rule or some weird quirk technicality. Pumpkins are berries. Water is technically lava. I’d bet dollars to donuts that the “acids are sour/spicy and bases are bitter” maxim will get you there +95% of the time
in this case, arguably the most famous and prevalent "spicy" food chemical (Capsaaicin) is not acidic. It's technically a base but its pH is not what influences the sensation of spice.
::deep exhale:: alright, ya know what everyone? Please disregard the afore mentioned LIFEHACK as it is not an immutable fact, and there are some common exceptions. I mean yes it applies to acids, acids are going to be sour/spicy because of the hydrogen ion that makes them acids in the first place, but what i SHOULD have said, is that things that taste bitter are bases, because bitter compounds contain amine groups which are weak bases. So rather than all bases are bitter, the better generalization would have been "all things that taste bitter are bases"
okay mich, please come on back with some more "well actually huuhhhgghh" because i'd bet my life there is something out there that tastes bitter that is not in fact, a base.
(or, perhaps as an alternative, don't!)
my deepest apologies to anyone for whom i have offended their delicate sensibilities.
