Brick ovens and tahonas often appear in descriptions of how a tequila is made. They belong to the stage that prepares harvested blue agave for fermentation: turning a dense, fibrous piña—the agave’s heart—into a sugar-rich liquid.
The preparation helps shape tequila’s aromas as well as providing food for yeast. Cooking makes the plant’s stored carbohydrates fermentable; extraction separates sugars or unconverted carbohydrates from the fibers. Distilleries use several kinds of equipment to do that work, and some systems extract carbohydrates from raw agave before converting them into sugars.
Cooking softens the piña and releases sugars
A harvested piña contains the agave's stem and fleshy leaf bases. Much of its stored carbohydrate is in fructans—chains built mainly from fructose units. Hydrolysis breaks those chains into smaller sugars that yeast can use.
For oven cooking, the distillery cuts the piñas into pieces so heat can reach them more evenly. Steam softens the agave and converts its carbohydrates. Sweet liquid released during cooking can be collected with the liquid prepared for fermentation.
Cooking also develops aromas. Heat drives reactions between sugars and amino compounds, producing substances with sweet, floral or vanilla-like aromas. A 2002 study of cooking liquid from one producer found many of these compounds in the tequila too.
Equipment for cooking and extraction
| Equipment | What it does |
|---|---|
| Masonry oven | Cooks pieces of agave with steam and converts stored carbohydrates into sugars |
| Autoclave | Heats agave pieces or extracted liquid under pressure to convert stored carbohydrates into fermentable sugars |
| Tahona | Crushes cooked agave with a large stone wheel |
| Roller mill | Crushes shredded agave; water washes sugars out of the fibers |
| Diffuser | Uses water to extract carbohydrates from shredded cooked or raw agave |
Ovens and autoclaves
A masonry oven cooks pieces of agave with steam. The cooking cycle includes time for heating, resting and cooling. Patrón alternates steaming and rest in its clay brick ovens over 79 hours.
An autoclave heats agave under pressure to break its stored carbohydrates into fermentable sugars. Depending on the distillery's system, it can cook pieces of agave or heat liquid already extracted from the plant. When agave is cooked before milling, the softened pieces go next to crushing and washing.
Tahonas and roller mills
A tahona rolls through cooked agave, crushing it under a large stone wheel. A roller mill mechanically crushes agave after shredding. Water washes sugars from the fibrous material into the collected liquid.
The fibers left behind are called bagazo. A distillery can separate them from the liquid or keep some in the fermentation tank.
Diffusers can work before or after cooking
With cooked agave, a diffuser washes out sugars already released by hydrolysis. With raw agave, it extracts stored carbohydrates that still need converting into fermentable sugars.
Mexico's tequila standard defines hydrolysis as conversion by heat, chemical treatment or enzymes. The treatment used after raw extraction depends on the production system.
Read the three routes as a table
| Production route | Order |
|---|---|
| Oven or autoclave followed by milling | Cook and convert → crush and wash |
| Cooked-agave diffusion | Cook and convert → extract with water |
| Raw-agave diffusion | Shred and extract with water → convert the extracted carbohydrates |
For fermentation, distillation and bottling, see How tequila is made.
Questions about cooking and extraction
Does a diffuser cook agave?
No. A diffuser extracts carbohydrates with water. Cooking or another hydrolysis treatment converts those carbohydrates into fermentable sugars. That conversion can happen before diffusion, with cooked agave, or afterward, with raw agave.
What is a tahona?
A tahona is a large stone wheel used to crush cooked agave. The crushed agave can be fermented with its fibers or separated from them.
Is tequila's production liquid the same as aguamiel for pulque?
No. Tequila's liquid comes from processing the harvested blue-agave piña. Aguamiel is the sweet liquid collected from a living maguey for pulque.
Does “100% agave” tequila specify the cooking or extraction equipment?
No. Under Mexico's tequila rules, “100% agave” means all fermentation sugars come from blue agave. It does not prescribe an oven, autoclave, tahona, roller mill or diffuser.
Sources
- Miguel Cedeño Cruz, “Tequila production from agave,” The Alcohol Textbook, fourth edition (2003), pp. 229–232.
- Academia Patrón (2021), pp. 42–47; Patrón's production guide.
- NOM-006-SCFI-2012, §§4.14, 4.18, 4.20 and 5.1.
- Mancilla-Margalli and López (2002), cooking-aroma study, pp. 810–811.