Understanding Mezcal

This guest blog post is focused on simplifying Mezcal and comes courtesy of Laura ‘Lala’ Noguera, a Mexican spirits expert and specialist in distillates of agave, rum, pulque and a cigar sommelier. She is also a researcher and writer for several magazines and brand advisor. The knowledge being shared by Lala is part of her legacy having walked through the 22 producing states in Mexico and meeting more than 350 ‘teachers’ to help others better understand agave spirits.

“Mezcal is looking for you, not you for him.” Lala Noguera

The Manufacturing of Mezcal and other Spirits from Agave.

The manufacturing of traditional mezcal will be explained here first, as it is the origin of all agave spirits.

In addition, we will mention the changes over time that have made industrial mass production possible. This is mainly used for internationally available tequila brands, but this does not mean that industrially produced spirits of other categories do not exist. In contrast, artisanal manufacturing of tequila has become very rare.

The manufacturing of traditional mezcal is certainly one of the most fascinating activities in the spirits business. The techniques used and their mastery are – without exaggeration – ancient art, passed down through generations within the mezcalero families. No control instruments or chemical additives are used here. Everything is based on selected raw materials, experience and feeling.

The mound is covered with a cloth, tarpaulin, palm or banana leaves to prevent the subsequently applied soil from contaminating the agaves. This layer, together with the 30 cm layer of earth, seals the pile airtight. The remaining oxygen burns off, the remaining fire goes out and evaporating moisture causes a slight increase in pressure inside.

A thick layer of earth seals the stove airtight as pictured below.

The kiln now rests for three to five days to ensure a slow transformation process; rarely is it kept sealed longer. Once the cooking process is complete, the oven is dismantled and the piñas are stored in a clean and dry place in preparation for the meal.

This storage time is important as it breaks down cellulose and facilitates the subsequent milling and fermentation process. Therefore, the storage time depends on the type of agave and varies according to local customs. Mould or insect infestation is nothing unusual, but sometimes even desirable.

The flesh of the agave is now soft and has a brown colour. It smells sweetish, freshly of plant juices and slightly of caramel. There are also notes of wood, smoke and earth due to the treatment in the earth oven (but the mezcal should not be over smoked, the burnt piñas should be removed from the grind and only the caramel coloured ones are ground, an overly smoked mezcal is a bad process when grinding the burnt piñas).

This technique has been known for several thousand years in Mesoamerica, i.e. cooking food in a conical oven. However, distillation is not pre-Hispanic, it actually first started when the Spanish brought the first stills to New Spain as a result of the conquest of Mexico. Let us remember that the Spaniards were subjugated for 700 years by the Arabs in the north of Spain, and for this reason they also obtained the knowledge of distillation, which they in turn brought it to the American continent.

For the further process, usually the whole plants are processed, but in rare cases only the juice is extracted by pressing and this is then fermented. This is also the case in industrial production, as pure liquid substances are easier to handle in an industrial distillery (for Tequila only).

Cooking and Steaming, Modern

Since the introduction of steam power and the machines available for steam generation (caldera), this technique has been rivalled by masonry ovens (hornos). Hot steam is blown into hermetically sealed rooms filled with agaves. This creates pressure and cooks the plants more efficiently than earth pits. Moreover, no smoky flavour remains in the final product.

Cooking in so-called hornos or masonry ovens, using steam at Tequila in Jalisco.

In the Tequila world, this method is now considered traditional, as there are already some even more modern and efficient techniques. The modern approach uses the autoclave, an industrial pressure cooker made of stainless steel, comparable in shape and size to the tank of a tanker truck. This enables cooking under controlled supply of steam, pressure and temperature. This shortens cooking considerably at high settings, but can also be run on low. Both produce very different results, similar to preparing food.

The latest development is the diffuser, a machine originally developed for making agave syrup. It allows an almost 100% yield of agave sugar and shortens the process of converting starch to a minimum. Green agave is shredded and the inulin is washed out of the fibre under high pressure. This ‘syrup’ is then saccharified by heating and adding acids and enzymes. However, this also creates undesirable flavours in the final product.

The diffuser allows the processing of very young, unripe agaves, which produce a ‘flat’ distillate. This is often remedied with additives. With the spread of the diffuser, the standard of the DO Tequila was also ‘adapted’ and the regulation for processing ‘fully ripe agaves’ was shortened to merely ‘agaves’.

Grinding, Traditional

In preparation for fermentation, unusable parts of the plant are first sorted out. These are usually overcooked or undercooked parts. The good pieces are then ground into a fibrous pulpy mixture (molienda). This is usually done by an upright mill wheel (tahona, molino egipcio or molino chileno), moved by draft animals or sometimes by a machine, which is guided in a circle around a central axle. The wheel runs in a low basin in which the agaves lie. A person always walks in a circle with the draft animal to pull the material in the basin under the millstone.

However, other types of grinding are also used. More anciently, and in low-output distilleries, the agave hearts are crushed with wooden hammers (mazo) or pounders in stone or wooden basins (canoa). Some distillers have small choppers, especially in Oaxaca, Puebla, Michoacán and Guerrero, where Agave karwinskii (madrecuish, cuish) is processed, which is still very hard after the cooking process. Whether the type of grinding has a significant influence on the taste is disputed even among distillers.

Grinding, Modern

In larger distilleries, agave is processed in roller mills, where the cooked material is crushed and pressed out onto metal rollers. In the diffuser, cooking and grinding are the same process. In both cases, the juice is separated from the solids.

Fermentation, Traditional

The plant pulp resulting from the milling process is now mashed. Different vessels can be used for fermentation (fermentación), depending on tradition and local availability:

Spontaneous fermentation of the agave mash with fibres in wooden vats. The stones used to weigh down the fibres are typical of the region around the 22 states of Mexico that distill 65 species of agave. Hollowed tree trunks, tubs made of natural or masonry stone, cow skins, clay pots and many others, but usually large wooden barrels (tinas) are used. All vessels are handled unsealed to ensure the access of natural yeasts that cause the spontaneous fermentation process. These and other microbes are found on fermentation tanks, tools and all objects in the distillery and are reproduced during each fermentation process.

Over time, autochthonous strands emerge that are adapted to the processes on site and produce a specific flavour profile for each distillery. Thus, the concept of terroir is applicable not only to the location of the plant, but also to the distillery.

Some distilleries use must from the previous fermentation process as a starter for the new batch. In some areas, pulque, i.e. fermented agave juice, is also added. Cultured yeast is not used in traditional mezcal. Depending on the size of the vessels, the outside temperature, humidity and the agaves used, the fermentación takes between a few days and up to two weeks in cool weather.

The end of fermentation is determined by the fading noise inside the vessel, the shape of the openings in the fibrous pulp floating on top (caused by escaping CO²), the smell, the temperature of the mash and the taste of a sample taken at different heights of the vessel. Each agave variety produces recognisable differences in the mash and has different fermentation times.

Once fermentation is complete, i.e. all usable sugars have been broken down into alcohol by yeasts, the mash is distilled. It now has around 5% alcohol. The must be distilled within one day, otherwise it will spoil. Therefore, in a traditional distillery, the size of the pit oven, the capacity of the fermentation tanks and that of the stills are coordinated and the result is a batch (or lot) that usually does not exceed a few hundred liters.

Fermentation, Modern

In contrast to the traditional approach, only the liquid parts are fermented in industrial production, not the solids, i.e. fibres.

These produce a more complex flavour, but also a higher methanol content. Liquid substances can easily be transported through pipes by pump in large-scale plants. They are inoculated with pure-breeding yeasts and fermented as quickly and efficiently as possible at a controlled temperature.

The aim is to achieve the highest possible alcohol content (yield) and a consistent flavour profile. Chemicals are often used to control or accelerate fermentation, e.g. sulphuric acid. Unfortunately, this is also the case with some traditional distillers in spontaneous fermentation as this allows them to offer a cheaper mezcal. Chemical-free production is in fact purely a matter of trust, as it is difficult to trace in the final product.

Distillation, Traditional

Usually stills made of copper (alambique) are used, but sometimes also those that are made entirely or partly of ceramic pots (ollas) or plant parts (reeds, agave shoots, bamboo, wood). All these types do not allow continuous distillation, i.e. a filling is completely burnt off before the still is opened again and refilled.

The most common is the copper still with a pot (olla, cucúrbita, retorta), helmet (cabezote, montera, capitel), spirit pipe (turbante, pasa-vapores) and snake cooler in a water bath (serpentín, culebra). There is no amplifier.

The manufacturing of mezcal for example from Santa Catarina Minas or Sola de Vega in Oaxaca is done by a still made of clay and reeds, called alambique filipino or hornalla, among others, with internal condensation.

This method is still used in some other places in Oaxaca, Jalisco (for Raicilla), Puebla and Michoacán.

The still is an amphora-shaped clay vessel, which is built into a body of adobe bricks flush with the upper edge and is fired with wood from below. A round clay vessel (resollano) is placed on top of it, which has openings of about 20 cm at the top and bottom. A copper bowl (cazo) is placed on the upper opening, which contains the cooling water.

The condensate forms on the curved underside of the bowl, falls into a wooden spoon (paleta) and is led through reeds (bitoque) through an opening in the montera to the outside into a collecting container.

Fires distilled in ceramics tend to be ‘denser’ and more oily than those distilled in copper.

Distillers in the Jalisco and Michoacan regions work in a similar way, although different materials are used here. While the actual pot containing the mash is made of copper, the upper part is made of wood.

In the case of small distilleries, this is made of a hollow tree trunk; in the case of larger distilleries, it is made of barrel staves. On top of these, in turn, sits a metal pan as a condenser.

Distillers with internal condensation were brought to Mexico around 1600 by Filipino slaves to distil palm wine (tuba). These very simple alambics are still in use in Asia today.

Mezcal is distilled twice, in rare cases (e.g. Pechuga) three times. Normally, the solids, i.e. the fibres (bagazo), are added to the still during the first distillation, so the separation from the must takes place during the first distillation. In a few areas, only the liquid must is processed.

1st distillation – wash distillation: the still is filled in equal parts with the liquid components and the fibres from the fermentation tanks. During the distillation process, the wash (ordinario, común, shishe) is produced with an alcohol content of 10 to 40%, depending on the type of agave.

2nd distillation – spirit distillation: The second pass (rectificación) produces the heads (puntas, cabezas), body (cuerpo, corazón) and the tails (cola). The body is consumed at the strength it comes out of the still at about 45% to 60% by volume, adjusted with the other fractions or diluted with water.

This is the procedure in Oaxaca when using copper pot stills. On the other hand, in Santa Catarina Minas, when ceramic stills are used, four fractions are separated: punta (heads, 59-80% by volume), cuerpo (body, 50-60% by volume), cola (tails, 10-20% by volume) and inguishe (no further information).

It is important to note: In mezcal, the quality of flavours and aromas depends on its alcoholic strength. If less than 40 degrees, the mezcal will smell more of alcohol and will have less agave flavours due to its dissolution (to lower graduation with distilled water). From 42 to 45 degrees it will have medium flavours and aromas, from more than 45 degrees to 55 degrees, it will have much more essence of the agave.

Distillation, Modern

All modern methods of distillation are used. The classical method of copper pot stills makes up the greater part of the quality product, but large distilleries use continuous distillation and sometimes gigantic column stills made of stainless steel, which usually produce less expressive spirits.

Product Control, Traditional

The mezcaleros during the drop tasting with a venencia made of reed (pictured above).

The product is controlled during distillation by dropping a small amount of liquid in a jet-like manner into a vessel, usually from a reed (venencia) into a calabash (jícara). During this process, bubbles (perlas, perlado) form, which give the master distiller information about specific qualities, mainly the alcohol content.

The bubbles should form a circle and, if possible, a closed ring around the edge of the bowl (cordón de perlas) and then cover the surface. In some areas, drinking horns or other vessels are also used for these tests. The master distiller also massages the distillate into the palms of his hands from time to time and smells it to pick up consistency and scents. Beyond that, a distillery has no measuring or control instruments of any kind, except for the experience of its maestro mezcalero.

Important notes:

• Do not always expect to taste espadin magueyes, there are 65 varieties that are distilled in 22 of the 32 cities that make up the United Mexican States (legal name of my country), so all agaves have different aromas and flavours according to their terroir, process and traditions.
• The mezcal should not necessarily be smoked or have a very light smoke, if it is over smoked it is due to a poor selection process of burnt agave piñas.
• Typicality is not necessarily being smoked, to understand typicality you must understand the state of the Mexican Republic where the agave is grown, its way of processing and distillation. There are mineral, fruit, herbal, floral, meaty, dairy, wet earth, and spicy flavours, but it will largely dependent on its fermentation and the type of indigenous yeasts involved.
• The beauty of mezcal appears on many occasions in its imperfections of the master distillers who are indigenous, self-taught of all their generations, of understanding nature, that the perfection of mezcal is in the adversities in which the mezcalero faces to translate the constant chat between the sun and the agave where he is the interlocutor. Remember that mezcal is the last vestige of alcohol made in an artisanal way by human beings and does not depend on machines.

• A mezcal can use agaves that took between 6 to 35 years to mature, so you will understand that after light years that have been feeding the plant, mezcal should be more valued and less underestimated.
• The smoothness in a mezcal of less than 40 degrees of alcohol means that it has more water and less agave essence, do not always expect to find only smoothness. The mezcals of more than 45 to 55 degrees (which is what the regulation in Mexico allows for mezcal) will have less alcohol in the nose and more flavour potential, what you must do is understand them and not look for smoothness, remember that the agave expresses itself in your body, if you don’t like it simply because the agave didn’t choose you, but if you like it feel lucky to drink the last distillate in the world made with your hands and the wisdom of understanding nature by the human being without technology, they are more wiser without having those tools than those who have them and depend on them.

Lala Noguera texts, based on books by Ulises Torrentera “Mezcalaria” “La Mezcaleria”