Making mezcal cannot be distilled to one single process or style, it is a spirit with a beautiful range of makers and techniques. There are 7 steps that are followed in palenques by mezcaleros, each with their own personal touch.
Unlike Tequila, which is made from only one type of agave. Mezcal is made from many different types of agave. There are over 300 species of agave that can be used for mezcal production. Some of the most commonly used are espadín, tobala, tepextate, madrecuixe and barril. Each species has its own unique growth cycle and maturity rate ranges from 7 years up to 35 years.
Because the agaves are in the ground for so long, they are even more subject to terroir than the popularized wine grapes. Rather than thinking about the genetics for each in regards to flavor, it's better to consider the conditions under which it was grown. From weather patterns to soil composition, these all affect the final sugar and mineral contents of the maguey.
Some agave used to make mezcal is cultivated and farmed, but many still grow wild, and in hard to reach places. Tepeztate, for example, loves living on the sides of steep, rocky cliffs, and takes nearly 30 years to mature. So if you’re out hunting agaves, you better know what you’re doing!
The best harvesters are mezcaleros who have truly studied the agave plant. Not only must they be able to identify them in the wild, but they deeply understand the rarity and delicacy of the agave species and what that means for future generations of both plants, and people. Mezcal makers and aficionados are constantly researching, and teaching on the importance of sustainability in preserving wild and rare agaves, and the threat that the quick growth of an industry can pose to the problem.
There are three categories of regulated mezcal - ancestral, artisanal, and mezcal - which all allow for different processes, but nearly all traditionally made, and respected mezcals use an earthen pit for cooking the agave. To begin, a pit is dug into the earth, usually 10 feet wide or more. No two ovens are exactly alike as each producer has their own design and philosophy of how it will influence the final flavor of the mezcal. The pit is lined with wood from local trees, and heavy volcanic rock or stones that will retain heat after the fire is lit.
The fire starts early in the morning, and rages for hours before it dies down, and now, the agaves are ready to go in. To protect the agaves from such hot direct heat on the stones, they are often lined first, with leftover fibers from previous productions. Quartered or halved agaves are piled on top until a mound is formed, and covered again with fibers or a blanket, and finally, earth. This pile is left to smoke for somewhere between 3 to 5 days. Cooking and steaming converts the inulin in the agave to sugars, which are needed to ferment into alcohol.
Cooking determines the amount and type of smoke that you’ll find in the final product. The type of fuel, wood, and the proximity to the direct heat all play a part in addition to the construction of the pit itself.
As we know from the Tequila making process, the importance of milling is to separate the agave sugars from the fibers. All while being careful to not crush them too much and release additional methanol. Ancestral and artisanal mezcal producers typically use a tahona, or macerate the cooked agave by hand using wooden mallets. Larger producers in the “mezcal” category are allowed use of a roller mill or even a diffusor but these methods are frowned upon within the industry.
Once the agaves have been crushed and the juices are flowing, it is time to ferment those sugars into alcohol. Fibers are allowed in fermentation for both artisanal and ancestral category production and are most often included. All juices and fibers(mosto vivo) are transferred to a container of choice which for the previously mentioned categories can include hollows in stone, soil or trunk, masonry basins, wooden or clay containers, and even animal skins.
Producers rely on naturally occurring yeasts in the air and containers to begin fermentation. Once the brew is bubbling, fermentation can last anywhere a few days, to a few weeks, depending on weather. Because the fibers are left in for fermentation, it can get really wild, really quickly so a close eye must be kept on the tinas to make sure they’re not bubbling over! When the reaction has stopped(mosto muerto), the liquid has transformed into a 4-5% ABV agave “beer or wine” that now must be distilled.
Distillation in mezcal is orchestrated using generations of experience with very traditional methods. You will not see continuous column stills or even stainless steel mills in most palenques. What you will see are stills made of clay or wood that are heated by direct fire and materials from the environment they’re built in. This could mean clay, dirt, wood, fibers, or branches. Most notably, these clay pots or wooden stills are not anywhere near the massive capacity of modernized stills and thus, batches are very small and unique.
Furthering its artisanal nature, the alcohol content during distillation is measured by the structure and lasting ability of bubbles or “perlas” created by pouring the liquid in a stream into a cupped vessel. Many maestro mezcaleros can read the ABV by sight to a degree or two without using scientific equipment.
Similar to Tequila, mezcals must be distilled twice, and can be distilled further, but most of the time are not.
As of 2020, a majority of the mezcal category remains as blancos or jovens - unaged expressions. Once they are perfected in the still, they’re bottled at a proof between 45 and 55%, and sent to market. You can read more about the different categories of mezcal and aging, here.
Mezcal accounts for only about 2% of the entire agave spirits market, but is increasing rapidly and is one of the fastest growing global spirits categories.