Tequila is an agave-based spirit made primarily in the area surrounding the city of Tequila, 65 kilometres (40 mi) northwest of Guadalajara, and in the highlands (Los Altos) of the western Mexican state of Jalisco. The red volcanic soil in the region surrounding Tequila is particularly well suited to the growing of the blue agave, and more than 300 million of the plants are harvested there each year. Mexican laws state that tequila can be produced only in the state of Jalisco and limited regions in the states of Guanajuato, Michoacán, Nayarit, and Tamaulipas.
Tequila is most often made at a 38–40% alcohol content (76–80 proof), but can be produced between 35–55% alcohol content (70–110 proof). Though most tequilas are 80 proof, many distillers will distill to 100 proof and then cut it down with water to reduce its harshness. Some of the more well respected brands distill the alcohol to 80 proof without using additional water as a diluter.