Simply, what causes a sour taste when smoking, why does it happen, and how does one cure the problem? Is this a sign the pipe hasn't had sufficient rest time? Urgent!
+1000Pay real attention to the gap between the tenon and the bottom of the mortise. Q-tips and alcohol should do the trick.
Sour—> Cleaning, yes. But there are other sources of sour besides mildew.Sour = mildew --> cleaning