the conical stone oven is a pit dug into the earth and lined with stones, where agave piñas are cooked for several days over firewood. The heat turns the agave's fructans into sugars that can later ferment, and the wood smoke gives mezcal its smoky touch. It is the main difference between artisanal mezcal and industrial tequila, which is usually cooked in autoclaves.
How is the oven built?
- A cone-shaped pit is dug and lined with stones.
- Firewood is lit at the bottom and stones are piled on top until red-hot.
- The stones are covered with wet agave fiber (bagasse) so the agave does not burn.
- The cut piñas are stacked in.
- Everything is covered with mats, tarps and earth to hold the heat.
- The agave cooks for several days, then cools before it is removed.
What happens inside the agave?
Agave does not store simple sugar but fructans (long chains of fructose, similar to inulin) that yeast cannot ferment directly. With heat and moisture over many hours, those chains break down (hydrolysis) and release fructose and other fermentable sugars. At the same time, Maillard reactions and caramelization darken the piña and create sweet, toasted, caramel aromas.
Where does the smoky taste come from?
From the agave's direct contact with the heat and smoke of burning wood inside a closed oven. The type of wood, cooking time and how tightly the oven is sealed change how smoky it gets. A good maestro wants the smoke to support the agave, not bury it.
How is it different from an autoclave?
| Stone oven | Autoclave | |
|---|---|---|
| Energy | Firewood, direct fire | Pressurized steam |
| Time | Several days | Hours |
| Smoke | Yes | No |
| NOM-070 category | Artisanal and ancestral (pit or masonry ovens) | Plain “Mezcal” only |
Why does control matter?
If agave is overcooked or burnt, compounds such as furfural can rise; NOM-070 caps furfural at 5 mg per 100 mL of anhydrous alcohol. Good cooking yields enough sugar without bitter or burnt flavors.
How this applies to ZUNTE
Maestro mezcalero Juventino Cruz cooks ZUNTE's Espadín for 4 days in a traditional conical stone oven in San Luis del Río. That is the source of the “hint of smoke” in its tasting notes: present but light, so the agave's herbal and citrus notes come through. This process is part of what lets ZUNTE be certified as Mezcal Artesanal by COMERCAM.
FAQ
Is all mezcal smoky?
Nearly all artisanal mezcal has some smoke, but intensity varies widely.
Is tequila cooked in stone ovens?
Most tequila today is cooked in autoclaves or steam ovens, without smoke.
How many days is the agave cooked?
Usually three to five, depending on the palenque and the load.
Sources
- NOM-070-SCFI-2016, Alcoholic beverages – Mezcal – Specifications (categories and furfural limits). DOF.
- Mancilla-Margalli, N. A. & López, M. G. (2006). Water-soluble carbohydrates and fructan structure patterns from Agave and Dasylirion species. Journal of Agricultural and Food Chemistry.
- ZUNTE Mezcal. “Our process”, zuntemezcal.com.
