Fermentation of pulque
So from Agave juice can still be pulque, a fermentation is necessary, and that is, the sugar molecules must be converted to alcohol. Usually yeasts are used (eg. For example, beer or wine), ie mushrooms for the acceleration of such fermentation processes. A special feature of pulque (and hence of mezcal and tequila) is that the fermentation is done by bacteria.
Originally, the agave juice was simply stored in burrows for fermentation. A typical living in the soil bacterium, the bacterium Zymomonas mobilis, which came in those same holes in the ground with the agave juice in contact and the fermentation set in motion. Later, when it began in the tequila production to store the juice in barrels rather than in holes in the ground, always had to climb into the drum of the harvest workers to begin the fermentation. Because his skin had sufficient earth and soil bacteria accumulated so in this way Zymomonas mobilis could enter the agave juice.
The fermented agave juice called pulque. It is a milky liquid with an alcohol content of between 5 and 10%.For the peoples of Central America, he was the drink of the gods. Drinking it alone was reserved for the priests, when they had to create prophecies in noise, and privileged people victims who were drinking in front of their sacrifice it. One day in the year of pulque was allowed to anyone, even if they only could afford the Elite him that day.
The taste already describes Karl May in his novel Waldröschen or the Avengers hunting around the earth pulque as something that would taste like "alum, licorice, aloe, copper sulphate, ammonia, Hollunderbeere soap and water". "Granted, Karl May never even pulque tried, but he has at least a right: the drink tastes very used to.