The must come up to 5% of alcohol, there is no rest of sugar to be transformed into alcohol by natural yeast, then. It is now time for distillation. The distilleries are made of copper or clay because of their low heat sensitiveness. This way they have proved their worth for long time. The distilleries are heated with wood, the distillate runs through common reed or bamboo cane and thus will fill containers standing by. This way of distillation takes a lot of time, but it is worth to be patient and wait for any drop to run through. This is authentic high quality Mezcal.
Genuine Mezcal is generally distilled twice but there is also a triply distilled brand called Pechuga.
The authentic Mezcal is not only a Mexican sanctuary, but also a distillate of very high complexity manufactured by indigenous people since more than 200 years. The Spanish conquerors demonised and prohibited the making of Mezcal. Thus it is fortunately due to some hard headed idealists and culinary guerrillas that it still can be found. We grateful owe this to these eccentrics that Mezcal now has found its way into the best restaurants throughout the world.