Does coffee ever leave a funky aftertaste in your mouth?!
Answers: Personally, I find that flavored coffees leave a strong aftertaste, as does adding sugar and/or milk to it. Try Kona coffee from Hawaii - it's the best!
I've only had that problem if I've used too much flavored creamer, or the coffee is too strong.
try filtering your water and make it again.
Try decreasing the amount of beans you use... I have found that different brands sometimes require different amounts of coffee to brew it the same strength as I am accustomed to. I find that brewing it too strong or if the beans have been roasted too dark, it can leave a bitter aftertaste.
Yes, some can. Try making it a little weaker, it just may be a bolder blend than you are used to.
If it didn't come from a fresh roasted bean, not a can, that's the problem.