It appears somebody neglected to mention to poor Mr. Clemens that when drinking Turkish coffee, one should stop when reaching the "mud." My first cup was exactly the same experience as this:
Of all the unchristian beverages that ever passed my lips, Turkish coffee is the worst. The cup is small, it is smeared with grounds; the coffee is black, thick, unsavory of smell, and execrable in taste. The bottom of the cup has a muddy sediment in it half an inch deep. This goes down your throat, and portions of it lodge by the way, and produce a tickling aggravation that keeps you barking and coughing for an hour.
From "Innocents Abroad, by Mark Twain, 1869
Incidentally, April 21, 2010 marks the centennial of Mr. Twain's death. Here's to you, Sam. American's Grandfather figure.