I had a research-student flatmate once with a large collection of stove-top espresso-makers, who had calibrated very exactly the stove settings which would ensure that, for each size of pot, it would just brew, generally over about three-quarters of an hour. She ended up with a treacly black caffeine-laden substance midway between coffee and bile, quite able to fuel one's Scrabble evening until 4am. Hot Lava Java was the perfect feedstock for the process.