wine yeast

Fermentation is magic: tiny single-cell organisms called yeast (classified as fungi), reproduce like crazy and eat the carbohydrates and sugars in the mosto (the liquid and fibers from crushed roast agaves)… and a byproduct is alcohol. This is how beer (and thus whiskies), wine, rum, vodka (imagine fermented potatoes, or even fermented sugar beets) are all made

empty tinas at bramaderos

Fermentation takes place in vertical wooden vats called tinas. They can be made of various woods: oak, cypress, pine, which slightly influence the flavor of the mezcal.

san andres

The crushed agaves, both fibers and juices, are moved to the tinas, the fluids in buckets, the fibers by pitchfork and wheelbarrow. Tequilas producers filter out the fibers, which is why good artisanal mezcal is richer and more complex. The rocks help keep the fermentation from bubbling up.

Los danzantes
Artisanal mezcal makes use of local native wild yeasts that are just there, looking for a good meal. After a while, the same strain of yeast tends to always be there, in the staves of the fermentation tanks on the milling surface or floating in the air. Most tequila producers use domesticated commercial yeast, usually wine yeasts: wild yeasts are unpredictable, so using commercial yeasts yields more consistent product. On the other hand, the edginess and ferality of wild yeasts usually makes artisanal mezcal more interesting. The Alipús producers have learned to collect the wild yeast from a good batch, save it, and then “inoculate” the next fermentation with this well-working wild yeast.
san juan deL rio

Good fermentation looks rich. It takes days, up to a couple of weeks if the weather is cold.


It helps the fermentation if you stir the mosto

Don Amado in San Juan Bautista Jayacatlan uses small clay pots instead of tinas.

Tina made from a tree trunk near Sola de Vega

Close-up of a Don Amado fermentation

Photos by Katherine Lewis, Linda Newton, and a tourist