Mezcal Is The Fastest-Growing Liquor In The US. Why Aren't Mexican Producers Cashing In? Making mezcal is really hard work. Mexican producers harvest agave by hand and cook it in giant, earthen ovens. Then they crush it using a 1,000-pound, horse-drawn stone and distill it in copper pots. Despite all this effort, Mexican producers aren’t making the big bucks, even though demand for the spirit is booming. While Mexican regulations do require mezcal to be made in Mexico, that hasn't stopped large,