Have you ever gotten up in the morning with a hangover and so desperate for caffinne that you decided to drink the last of the cold coffee that had been sitting in the pot since the night before? At someone's house where they use cheap coffee and put in twice as much coffee as they are supposed to? And also, they reuse their filters? And make coffee using their weird hard tap water that leaves red stains on their sinks and stuff?
I have, and I think that's what Raktajino probably tastes like.