Tequila Elaboration Process

Tequila production begins with the planting of the Agave tequilana Weber, blue variety, an essential ingredient for the production of this spirituous beverage. According to the General Declaration for the Protection of the Tequila Denomination of Origin and the Official Mexican Tequila Standard, this agave species must meet certain criteria to be used in the production of Tequila:

1. The agave must be grown in a specific region designated by the appellation of origin declaration.

2. The agave must be registered in the registry of the Tequila certifying body.

The agave requires an average of 7 years to fully mature, at which time the maximum concentration of carbohydrates in the plant is achieved. Inulin, a high molecular weight fructose polymer composed of about 43 fructose monomers, with a glucose molecule at each end, is the predominant carbohydrate.

Once the agave has matured, in general the steps of the production process are as follows:

Jima of the Agave tequilana Weber (blue variety)

This is a critical procedure in the production of Tequila, which involves the careful separation of the unusable parts of the agave, specifically the leaves or stalks, when the plant has reached optimum maturity for processing. The fruit of this meticulous work is the obtaining of the "pineapple" of the agave, which is composed of the stem and the base of the leaves, where the essential carbohydrates for the distillation of Tequila are concentrated. The Coa, a specialized tool, is essential in this process, allowing the jimadores to make precise and efficient cuts to extract the piña with maximum efficiency.

Inulin Hydrolysis

This is an essential step in the production of Tequila, where inulin, the main carbohydrate in agave, which is a polymer of fructose and glucose, is broken down. This polymer is not fermentable by yeasts, so its transformation into simple sugars, mainly fructose, is required to continue fermentation. The methods used for hydrolysis include thermal, enzymatic or a combination of both. In addition, compounds that contribute to the organoleptic profile of Tequila are formed during this process. Hydrolysis is carried out in masonry ovens or autoclaves, applying steam at temperatures of 100 to 110°C (212 to 110°F).

This process is complex and can influence subsequent stages of production. For example, agave contains several carbohydrates, known as fructooligosaccharides (FOS), which vary in size and branching. These hydrolyze under different conditions, and those suitable for the more complex chains may be too intense for the simpler ones, leading to caramelization of the simpler sugars and the formation of by-products such as furfural and hydroxymethylfurfural, which inhibit fermentation.

In addition, excessive hydrolysis can generate methanol by demethylation of agave pectins, which is problematic because methanol can form compounds with ethanol, making it difficult to separate during distillation. On the other hand, insufficient hydrolysis results in the loss of sugars. Glycoproteins are also formed during hydrolysis, which can contribute distinctive flavors and aromas to Tequila, but can also represent losses in the process.

Sugar extraction

This is a fundamental phase in the Tequila production process, which can be carried out before or after hydrolysis. In this stage, the carbohydrates or sugars contained in the Piñas are separated from the vegetable fiber. Traditionally, this process is carried out by means of a combination of a shredder and a train of roller mills, which shred the pineapple and extract the sugars.

Although less common, Tahonas, large stones that rotate on a floor, are still used to crush the Piñas, a method that has been part of the tequila tradition since its origins. However, modern technology has introduced the use of diffusers, which optimize extraction by injecting hot water or steam through the agave fiber, allowing more efficient recovery of sugars.

Diffusers, being more efficient and less labor-intensive than traditional methods, have gained popularity in the industry. Generally, when diffusers are used, extraction is performed prior to hydrolysis, as it facilitates the separation of sugars and improves the efficiency of the subsequent process. This modernization in the extraction technique is a reflection of the balance between the preservation of traditional practices and the adoption of technological innovations in Tequila production.

Must formulation

Tequila production is a process defined by the Mexican Official Standard, which distinguishes two categories of distillate: 100% agave Tequila and Tequila. 100% agave Tequila is made exclusively with sugars derived from agave. The formulation for this category involves transferring the agave juices to the fermentation vats, followed by the addition of yeasts, pH calibration to favor yeast activity and setting the appropriate temperature (°T) for fermentation. The product of this stage is the fresh must, ready to begin the fermentation process.

On the other hand, the Tequila category allows the inclusion of up to 49% of sugars from alternative sources to agave. In this case, the formulation consists of combining agave sugars with those from the other source, taking care that the contribution of the latter does not exceed 49% of the total reducing sugars, expressed in mass units. This process also includes the addition of yeast, pH and temperature adjustment, resulting in fresh must ready for fermentation.

Must fermentation

This is a key stage in the production of Tequila, where yeasts convert the sugars present in the must into ethyl alcohol (ethanol) and carbon dioxide. In addition to these main products, other compounds are generated that define the sensory characteristics of Tequila. Although fermentation is not a universal process in nature, it is vital for certain organisms, such as yeasts, which use it to generate energy under stressful conditions, such as the absence of oxygen.

The fermentation reaction can be represented by the chemical equation:

C6H12O6 → 2C2H5OH + 2CO2 + ATP + 17.015 cal.

This indicates that 180.16 g of glucose is converted to approximately 92.14 g of ethanol.

Critical factors in this phase include temperature (32 to 35°C), pH (4-5), nutrient availability and prevention of contamination by competing microorganisms. Control of these parameters not only promotes fermentation but also reduces contamination by fungi and bacteria. Other elements to monitor are the presence of calcium and sulfur, yeast flocculation and foam formation. Calcium can cause yeast flocculation and precipitation, preventing complete fermentation of sugars. Sulfur, as a contaminant, inhibits fermentation. Foam can cause spills and leaks, so some companies use defoamers.

It is important to note that a temperature increase above optimum can be lethal to yeasts, stopping fermentation and causing inefficiencies. In addition, elevated temperatures can favor ethanol evaporation and a more violent release of carbon dioxide, which can result in higher ethanol losses during the process.

Distillation of the fermented must

This represents a critical phase in the transformation of fermented must into Tequila. At the end of fermentation, the musts have an alcoholic concentration ranging from 4 to 10% Alc. Vol. with minimal amounts of residual sugars. The distillation process is based on the difference in volatility between ethyl alcohol and water; alcohol, being more volatile, vaporizes at a temperature lower than the boiling point of water. The alcoholic vapors subsequently condense, resulting in a liquid enriched in alcohol.

Distillation is usually carried out in stills and has two main stages, although column distillation is also used. In the first stage, known as shattering or exhaustion, the less volatile components are separated and removed, such as the remains of yeasts, nutrients, solids, some secondary alcohols such as methanol, and other compounds called higher alcohols, as well as water. This residue is known as vinasse.

The resulting liquid, called ordinario, undergoes a second distillation or rectification, where the most volatile components are concentrated, thus obtaining Tequila. Rectification refines the quality of the distillate, eliminating impurities and ensuring the purity of the final product.

The resulting Tequila has several possibilities for bottling and maturation. It can be bottled directly as Tequila blanco, or it can be bottled as Tequila joven. Alternatively, it can be sent to barrels for maturation, a process that results in reposado, añejo or extra añejo Tequila, after which it is filtered and prepared for final bottling. Each of these processes contributes to the complexity and distinctive organoleptic profile of Tequila, reflecting the richness of Tequila tradition and the precision of modern science in its production.

Tequila maturation

It is an essential process in the production of Tequila that is governed by strict regulations. According to the Mexican Official Standard, rested Tequila must be aged in oak or oak barrels for at least two months. In the case of aged Tequila añejo, the maturation period extends to a minimum of one year in barrels with a maximum capacity of 600 liters. For Tequila extra añejo, the aging time is extended to three years under the same conditions.

This process must be carried out within the territory designated by the Declaration and by an Authorized Producer, thus ensuring the authenticity and quality of the product. During maturation, factors such as temperature, humidity, initial alcohol content, time and number of cycles of use of the barrels are determining factors in the evolution of Tequila, directly influencing its color, aroma and flavor.

Throughout maturation, a series of chemical transformations take place: the higher alcohols decrease as they are absorbed by the active carbon in the barrels, which contributes to a distinctive smoky flavor. Compounds extracted from the wood, such as tannins, impart color and characteristic aromas. In addition, new molecules are generated from the interaction of Tequila's components and oxidation of both the original elements and those derived from the wood occurs, resulting in a complex and enriched organoleptic profile.

Maturation is not just an aging process; it is an artisanal transformation that gives Tequila its unique identity, allowing each sip to reflect the history and terroir of its origin.