sign in sign up
<<
Home , Capacha, Mezcal, Pulque

● ALCOHOLIC BEVERAGES

Agave salmiana

Waiting for the sunrise

‘ to wake the living; to wake the dead’ - old Mexican proverb. Before corn was ever domesticated, ( spp.) identifi ed it with a similar plant found at home. Agaves fl ower only once (‘mono- were one of the main carbohydrate sources for humans carpic’), usually after they are between in what is today western and northern and south- 8-10 years old, and the plant will then die if allowed to set seed. This trait gives western US. Agaves (or magueyes) are perennial, short- rise to their alternative name of ‘century stemmed, monocotyledonous succulents, with a fl eshy leaf plants’. Archaeological evidence indicates base and stem. that agave stems and leaf bases (the ‘heads’, or ‘cores’) and fl owering stems By Ian Hornsey and ’ixcaloa’ (to cook). The name applies have been pit-cooked for eating in Mes- to at least 100 Mexican that oamerica since at least 9,000 BC. When hey belong to the family Agavaceae, have been distilled with alembics or they arrived, the Spaniards noted that Twhich is endemic to America and Asian-type stills. Alcoholic drinks from native peoples produced ‘agave ’ whose centre of diversity is Mexico. agaves can be divided into two groups, although their writings do not make it Nearly 200 spp. have been described, according to treatment of the plant: ’cut clear whether this referred to ‘ferment- 150 of them from Mexico, and around bud-tip drinks’ and ’baked plant core ed’ or ‘distilled’ beverages. This is partly 75 are used in that country for human drinks’. The fi rst method deals with the due to lack of processing details and food, fermented and distilled beverages, living plant (e.g. ), while the latter partly to the fact that the Spaniards used fi bre, and fodder. Some 50-odd species destroys it (e.g. mezcal). Most Mexican the same word to describe both types of are used to make ‘mezcal’, the generic alcoholic beverage production processes drink. name given in Mexico to distilled spirits from agaves involve complex fermenta- Mesoamerican civilizations have pro- such as tequila and ; these tions involving both yeasts and bacteria. duced alcoholic beverages from agaves drinks being distilled from the fermenta- As well as being used for food and since pre-Hispanic times, and consump- tion of juices obtained from baked plant beverage production (including act- tion of these products has played a vital cores. ing as ‘water substitute’), agaves have role in the religious and secular lives of The word ’mezcal’, is derived from been used for clothing and a source of these peoples. In Mexico in particular, ’mexcalli’ in the native Náhuatl lan- herbal medicines. The name ‘maguey’ traditional alcoholic beverages have guage; a combination of ’metl’ (agave) was introduced by the Spaniards who always played an important role in daily

36 z Brewer and Distiller International August 2016 www.ibd.org.uk ALCOHOLIC BEVERAGES l

an ethnographic record of the Aztec peo- only survived via clandestine bootleg- ple. The work commenced in 1545 and ging, which consisted of of completed ca. 1580 and was originally fermented coconut and agave juices. published as the Universal History of the It was only possible to avoid Colonial Things of New Spain. Lavishly illustrated prohibitions by fermenting in sealed by native artists, it has been described underground pits carved from bedrock, as “One of the most remarkable ac- and by using small, easy-to-use, stills counts of a non-Western culture ever that were easy to hide. composed”. The importance of agaves and pulque in are central to Pulque Sahagún’s work. Traditionally, pulque, which is first de- After the Spanish Conquest, the art picted in Indian stone carvings around of ‘western’ distillation was introduced AD 200, was made by spontaneous to Mexico and the agave distillates fermentation, or by using a pre-fer- such as tequila evolved, and these also mented starter, but nowadays it is also have exalted status in that country. The produced on a small industrial scale The goddess Spanish had learned their distillation through inoculation of aguamiel with a life, and their production and consump- techniques from the Moors who had pure, mixed starter culture. Because an tion have become deeply embedded conquered parts of their homeland, but, artisanal fermentation rarely ferments in various customs and rituals. Agave as we shall see, a crude form of distil- out completely, attempts to bottle the sap (or aguamiel) has long been used lation may have been practised even final product usually fail spectacularly – as a base for pulque the national earlier. Agaves still play a prominent role whereas modern commercial samples of Mexico, a Mexican icon, and one of in the culinary traditions of Mexicans can be canned and exported. the oldest alcoholic beverages on the and Amerindians of the south-west Pulque (or metoctli in the indig- American continent. Some would argue American deserts. enous language), the oldest that, not having a grain base, pulque It was 1521 when Hernán Cortés and most traditional of Mexican alco- is not technically a beer. According to and his accompanying holic drinks, is a milky white, viscous, mythology, the agave goddess Mayahuel subjugated the and, prior to the slightly acidic, drink (3.0-6.0% ABV) discovered the fermentation of aguamiel, Conquest, legitimate consumption of produced from the sap from several and legend has it that this sap which alcohol was mostly ceremonial, and Agave species, mainly A. salmiana, A collects in the centre of the plant is the confined to the upper strata of society, mapisaga, and A. americana. Not having blood of Mayahuel. Magueys thrive best the elderly, and the wise. a grain base, pulque is not technically in the cold, dry climates of Mexico’s Ceremonial drinking was mostly a beer, although it is often erroneously central highlands to the north and west undertaken to honour (or placate) the described as such. Because of its great of , where the best pulque is gods, to bless collective tasks and to historical, religious, social, medical, produced. promote fertility of the land. Commoners and economical importance, it is the were allowed to partake only in certain most widely studied and documented Indigenous alcohol and the circumstances; women after giving of the agave-based drinks. In Aztec Spanish Conquest birth and males after exhausting tasks; Mexico, pulque played a major role in The was vast and popu- drunkenness was looked upon as a daily life, and was a decisive influence lous, spanning Central America from grave misdeed. Habitual drunkards were on religious and war rituals. A mural sea to sea and encompassing some 20 considered unworthy neighbours and million subjects, around one-tenth of had their homes demolished; persistent whom lived in the capital Tenochtitlán offenders were executed. (now Mexico City). They employed a pic- The one exception to the aversion tographic writing system and produced to overindulgence was “The Days of numerous texts, most of which were the Dead”, a five-day binge in which burned after the Conquest - so we know everyone participated! Legend has it little of Aztec domestic life. It should be that the , one of Mexico’s greatest remembered that the Spaniards arrived civilisations, were destroyed through the ”to convert the barbarous Indians into misuse of alcohol. After the Conquest, peaceful and civilized people”. (sic), but pulque was taxed and there were no laws Women drinking pulque; from Codex Mendoza surviving Aztec accounts tell a different controlling its consumption. This laxity story. One of the earliest post-Conquest is often cited as being the reason for the texts containing references to pulque and rapid moral decline of the indigenous the daily life of the Aztecs can be found peoples and by 1672 the moral and in Codex Mendoza written in around 1541. physical health of the masses had sunk Consisting of text and traditional Aztec to such a low level that the govern- pictograms, the work was collabora- ment introduced regulations to control tion between native artists and Spanish (reduce) pulque consumption. This was priests. mainly achieved by limiting the number Another remarkable text, the of outlets () – only 36 being 4-volume (12-book) Florentine Codex, allowed in Mexico City, for example. was compiled by the Franciscan friar In the early post-Conquest Mexico, Bernardino de Sahagún and represents indigenous distillation was outlawed and Agave plant and jar of pulque; from Florentine Codex www.ibd.org.uk Brewer and Distiller International August 2016 z 37 l ALCOHOLIC BEVERAGES

fermentation commences. A thick, floating layer is then formed, indicating that the mixture is ready for a second fermentation. To initiate this, another batch (600-900 L.) of best-quality sap is then mixed with the starter at a rate of 1-3%v/v. This occurs in a tank called the ‘head fermenter’ and fermentation will proceed until the sugars have been exhausted. A batch (300-400L.) of the supernatant (essentially pulque, and called pie de cuba) is removed, and poured into a second vessel, the ‘tail fermenter’, and used as an inoculum (50% v/v) to ferment a batch of regular sap. After several days in the tail fer- menter, the desired ABV, viscocity, and sensorial characters are attained, and Part of mural from Pyramid of Cholula the product is barrelled. Essentially, this process is semi-continuous, since, dating from ca. AD 200 at the Great brewer, will eliminate the floral bud on withdrawal of batches of pulque Pyramid of Cholula, showing drink- (‘castration’) which is the initial step in from the head fermenter, the bulk of ing scenes (Los bebedores), indicates artisanal pulque production. the microbial population is retained for the significance of pulque as a ritual Castration leaves a cavity (cajete) subsequent sap additions. intoxicant in Aztec times. Cholula is in the centre of the agave stem. The Anything from 2-15 hL sap can be reckoned to be the largest man-made plant is then left to ‘age’ for at least obtained from a single plant, the prin- pyramid in the world. one month, which enables maturation cipal sap components being shown in The conquering Spaniards thought of the central leaves, and elevation of Table A. Aguamiel provides a suitable that it was the Otomies Indians who the aguamiel sugar content (to 7-14% medium for the spontaneous growth of discovered how to make pulque, mainly w/v). The healed cavity is then scraped the necessary microbes. because: “They were a tribe of half- to permit the aguamiel to flow freely naked barbarians who went about in again, and this will accumulate in Pulque microbiology an intoxicated state brought on by the the natural recess. Aguamiel is then Most of the microbes needed for sap drinking of made from maguey”. removed to a container – traditionally fermentation can normally be obtained The Aztecs distinguished three differ- by means of oral suction via a dry, hol- from the walls of the cajete, the uten- ent pulque-type beverages: metocli, or lowed-out gourd, called an acocote – sils used for scraping and transferral, ‘agave wine’; iztacoctli, or ‘’, and then transferred to a shed, called from the atmosphere, or from insects and teoctli, or ‘ceremonial wine’. A a tinacal, where aguamiel volume is (e.g. fruit flies, Drosophila spp.), but sample that had become too aged, and assessed and an inoculum added prior starter cultures increase the popula- had an unpleasant odour and flavour to fermentation, which takes place in tion of essential microbes, and ensure was referred to as poliuhquioctli, and open (ca.700 L.) containers. Originally, a more rapid and regulated initiation of it is from this word that the term ‘pul- these would have been of wood or ce- fermentation. que’ is derived, although it was used by ramic construction, but these days are The most important organisms the Spaniards to describe the freshly- often made of plastic. After fermenta- for sap fermentation are bacteria and prepared drink. tion, pulque is usually put into barrels. The initial removal of sap prompts the Average weight (%w/w) in dry matter Agave preparation plant to produce more, and this re- Pulque is made from the sweet, yellow- secretion will continue for at least one Fructose 32.4 ± 3.9 ish, slightly cloudy sap (aguamiel; pH month, with collections being made Fructo- 10.2 ± 5.7 7.5; SG 1.048-1.050), which is extracted twice-daily. This nutritious aguamiel oligosaccharides from mature (8- to 10-year-old) agave may either be fermented (pulque), Glucose 26.5 ± 2.7 plants, that are about to produce their drunk fresh, or thickened into a syrup. Sucrose 8.8 ± 6.5 Free amino acids* 0.26 ± 0.005 (only) inflorescence (quiote). As a plant Protein 3.0 ± 0.6 approaches flowering, a sugary sap Semi-continuous fermentation Ash 3.3 ± 0.8 is produced to nourish the developing Pulque fermentation is either sponta- flower bud which develops among the neous, or a response to the addition *Apart from methionine, all of the essential amino acids were present in all samples with most being central leaf bases (meyolote). The flow- of a fermented sap starter culture found in unvarying amounts. Levels of arginine, aspartic er will be formed at the tip of a long (see above). The latter is made initially acid, and alanine, however, gradually decreased during stalk. Flowering is a protracted pro- from around 10-15L.of highest quality the harvest period, probably due to their involvement in metabolic pathways. Interestingly, the non-protein cess and may take up to four months sap, which has been auto-fermented amino acid and neurotransmitter, γ-aminobutyric acid during which time anything up to 10 in a small closed vessel. After several (GABA) was detected in some aguamiel samples. hL of sap may be produced. Cultivated weeks, depending on environmental Table A - Average composition of aguamiel plants rarely reach sexual maturity, for factors (temperature, etc.), the alco- from three A. mapisaga plants thoughout the farmer (pulquero), who is often the holic fermentation ends and an acetic their harvest period

38 z Brewer and Distiller International August 2016 www.ibd.org.uk ALCOHOLIC BEVERAGES l

Preparation of pulque

Agave ‘castration’ Castrated agave Scraping the cajete

Removing aguamiel with an acocote

Transport of aguamiel to tinacal ‘Weighing’ aguamiel in tinacal

Inoculum and pulque fermentation Transferring pulque to barrel www.ibd.org.uk Brewer and Distiller International August 2016 z 39 l ALCOHOLIC BEVERAGES

pH 3.5-4.0 and contributes some lactic acid, of preserving and canning it has been ethanol 4.0-6.0 v/v acetic acid, acetate, acetone, glycerol, developed and the product (usually ca. total acidity (as lactic acid) 400-700 mg/100ml acetaldehyde, acetylmethlycarbinol, 6% ABV) is now exported to the US. fixed acid (as lactic) 200-400 mg/100ml and gums to the drink. In order to flavour pulque, or to mask reducing sugars (as glucose) 200-500 mg/100ml The main alcoholic fermentation is its occasional unpleasantness, fruits protein (N x 6.25) 300-500 mg/100ml esters (as ethyl acetate) 20-30 mg/100ml carried out by a number of microbes, (cantaloupe, water melon), ground aldehydes (as acetaldehyde) up to 2.5 mg/100ml the early stages being dominated seeds (pine nuts, pecan), vegetables fusel alcohols 80-100 mg/100ml by non-Saccharomyces yeasts, such and cereals may be added. total solids 2.0-3.0 g/100ml as Candida spp. (C. parapsilopsis; C. In light of the way artisanal pulque ash 200-500 mg/100ml lusitaniae), Kluyveromyces marxianus, is manufactured and consumed, the Table B – Physical characteristics of pulque K. lactis, Hanseniaspora uvarum, Pichia drink is exposed to multiple contami- spp., and Torulaspora delbrueckii. As nation risks. Food-borne pathogens, yeasts, although some filamentous fungi ethanol concentration increases, S. such as S. typhimurium, Staph. aureus, are also present. In both sap and fresh cerevisiae, S. bayanus, S. paradoxus, L. monocytogenes, Shigella sonnei, and young pulque, there is a predominance and strains of K. marxianus dominate. S. flexneri were all inactivated by the of bacteria over yeasts, caused by the Apart from LAB and Zymomonas, the pulque fermentation process. neutrality (pH 7-7.4) of the medium. The bacterial flora includes: Acetobacter yeast population increases gradually aceti, Bacillus subtilis, Cellulomonas Distilled beverages during fermentation, and these organ- sp., and Escherichia sp. Although the Historically, we have to conclude that isms eventually become dominant when flora of aguamiel will vary with loca- distillation was unknown in pre- the pH drops to around 4.5. There is a tion, S. cerevisiae, L. mesenteroides, Columbian America, for not one of four-fold change in the type of micro- and Z. mobilis are regarded as essen- the 16th century chroniclers records flora during fermentation, after which tial microbes in pulque fermentation. the presence of stills among a native putrefying organisms take over. No standardised fermentation process group. In the late-19th century, how- The initial community is dominated exists for pulque production because ever, there was documentary evidence by lactic acid bacteria (LAB) of the producers do not control factors such of much more ancient distillation genera Leuconostoc and Lactobacillus; as temperature. At present, there are processes in Mexico. In 1893 John the very early stages being dominated no regulations covering the alcohol Bourke witnessed apparatus used by two subspecies of Leuconostoc mes- content and/or pH in pulque, although by the Tarascan Indians around Lake enteroides. These increase sap acidity, the Mexican government is developing Pátzcuaro, in western Mexico, to make reduce oxygen tension, and develop the guidelines. mezcal. Via what he called ‘a primitive necessary viscosity through produc- alembic’, the locals made “A product tion of dextrans. It has been suggested Part of the daily diet that was exceptionally good and clear”. that, historically, the high viscosity The main flavour-active fuselols and The still parts consisted of a fire (a) imparted by dextran-producing bacte- esters identified in pulque are: ethyl with a smoke outlet (b); hoops (c,d) ria would have meant that consuming acetate (121 μg/mL); iso-amyl alcohol for the wooden barrel (h) forming the pulque during times of shortfall of [3-methylbutanol] (76 μg/mL); optically still body; earthenware bowl (‘kettle’) other food crops would have helped to active amyl alcohol [(-)-2-methylbutanol] containing “maguey mash” (e); cooling ameliorate the sensations of hunger. (22μg/mL); iso-butyl alcohol (22μg/mL), bowl containing continually replen- LAB growth produces lactic acid, and n-propyl alcohol (13μg/mL). ished cold water (f); metal catch-bowl ethanol, and secondary metabolites By definition, the refractometer (g), placed at an angle; side-tube con- such as fatty acids and their esters, or- reading of a pulque sample should be sisting of an agave stalk (k); collecting ganic acids, and higher alcohols, which 25-30 at 20°C (RI; 1.3365-1.3380), and bowl (l). creates an environment unsuitable for other characteristics are shown in Bourke noted that “Only the centre pathogenic bacteria but conducive for Table B. of the plant, resembling a cabbage the growth of ethanologenic bacteria, When the Aztec empire disinte- head and called the heart, was used, such as Zymomonas mobilis ssp. mo- grated, pulque lost most of its religious the exterior leaves being rejected”, bilis, and yeasts. Z. mobilis is a crucial significance, but retained relevance organism in the pulque fermentation, as a nutritional supplement and water substitute. Once the drink became profane, it was introduced into the country’s large conurbations, par- ticularly Mexico City. Today, it is the preferred drink for the low-income population, and, because of its vitamin (C; B-complex; D, and E) and essential amino acid content, forms an impor- tant part of their daily diet. Traditional- ly, pulque has only been sold in special taverns (pulquerías), but latterly it has been promoted in restaurants, with the intention of it becoming more popular with the younger generation. The drink is inherently unstable, with a shelf- Pulque; ‘natural’ (R) and ‘with pinenut’ (L) life of a couple of days, but a means Tarascan still (From Bourke, 1893)

40 z Brewer and Distiller International August 2016 www.ibd.org.uk ALCOHOLIC BEVERAGES l

and briefly described processing as follows: “These hearts were first baked in ‘mescal pits’ lined with heated stones and covered with wet grass and earth. Upon being transferred to shallow basins made in the ground and lined with flat rocks they were mashed into a coarse pulp with heavy wooden mallets, and then exposed to the sun to ensure fermentation. It was this fer- mented mass which I saw placed in the kettle of the still”. He also noted that: “The wooden barrel was very rude in construction, the gaping seams being closed with wet clay and gum”. Bourke ends with the information that: “Mescal is distilled in all parts of Mexico, in the rudest hamlets, in the most secluded mountains, but always Huichol still (from Lumholtz, 1902) Cora still (from Lumholtz, 1902) in the manner above described. A finer in shape of a small earthen jar, is the funnel, to catch the vapours, while liquor called tequila is made by distill- suspended above the large pot by two the stem passes through a square hole ing the fermented sap of maguey”. strings of yucca fibre, which, in turn, in the lower half of the cylinder. The A little later, explorer Carl Lum- are kept in place by the pressure of the liquid is in this way carried outside of holtz noted that the Huichol Indians cooling-vessel against the inner wall the funnel, and falls directly into a jar of west-central Mexico were using an of the mound. It is thus in the proper placed under the end of the trough.” unusual distillation apparatus, saying place to intercept the drops of con- Another ‘basic’ still-type was that these people “Make a harmless densed vapours as they fall from the described later by Fr. Antonio Tello in a toach [tuchi is a ‘soft mezcal’ – now bottom of the cooler.” 1623 Franciscan work entitled Crónica largely disappeared] and a stronger miscellanea de la Santa provincial de mescal, both made from agaves”, Primitive stills Xalisco. Originally used in the 16th and and that: “The preliminary treatment Lumholtz was of the opinion that 17th centuries by emigrant Filipino of the plant is identical for each”. the stills were “so old and rustic in sailors to distil ‘coconut wine’, Tello Lumholtz then explains: “The hearts appearance” that they implied “A tells us: “The stills are hollow trunks, of the plants are baked between hot pre-Conquest knowledge of distil- the thickness of a man, covered by a stones in an earth mound; then they lation”, adding that: “The process of copper encasing full of water, which are crushed, mixed with water, and left distilling among the Huichols is, to my is changed as it is heated, and in the to ferment in cowhides, each of which knowledge, the most primitive on the middle of the hollow part there is a is suspended between four poles. After American continent”. The neighbour- round fitted board, with a pipe pro- the mass has stood in this way in the ing Cora Indians used another primi- truding from one side, through which open air for about a week it is ready for tive still, which Lumholtz considered distillation occurs.” Together with the distilling. A primitive method of distil- “Only a step higher”. He describes it coconut, coconut wine (called tuba) lation, which I am inclined to consider thus: “The funnel is a cylinder, over was probably introduced to western pre-Columbian, may yet be found in a yard high, and formed of a piece of Mexico in pre-Conquest times by Fili- practical operation among the Huich- bark from the mountain cedar by join- pino sailors, who then distilled it (vino ols in their remote mountain fast- ing the long sides firmly together with de cocos). nesses. Their distillery consists of a native glue. According to Joseph Needham, mound of stone and mud, built around “As a receiver the Cora use a a large earthen jar or boiler, with two trough, consisting of a maguey leaf cut additional vessels which complete the in the shape of a spoon. The bowl of apparatus.” this spoon is fitted obliquely inside of The lower part of the mound forms an oven with two openings on opposite sides, for the draught, and here the fire is built around a stone on which rests the big vessel that contains the fermented mass. The upper part of this jar fits tightly into the mound, which forms a kind of funnel above it. Three thick rings of grass are laid, one on top of the other, over the rim of the boiler to make the funnel more solid. Condensation is effected by means of a copper vessel placed on top of the fun- Capacha Culture vessels; ‘Trifid’ (left); ‘Gourd’ ‘Asian still’ for making ‘mezcal de olla’, Mazamitia, , nel and kept cool by being constantly (right) [From Zizumbo-Villarreal et al., 2009 - Mexico (from Valenzuela Zapata & Gaytan, 2012 - by kind refilled with cold water. A receiver, by kind permission] permission) www.ibd.org.uk Brewer and Distiller International August 2016 z 41 l ALCOHOLIC BEVERAGES

the Huichol still is an example of say that researchers presently disa- that amount. has unique a ‘Mongol still’, while that used by gree on the origin of distillation in the characteristics for tequila production, the Cora Indians is a ‘Chinese still’ Americas. including high inulin content, low fibre type. Needham also mentions the content and the appropriate aroma and ‘gourd’ and ‘trifid’ pottery vessels Mezcal and tequila flavour compounds. Attempts to pro- characteristic of the Capacha Culture The original term ‘mescal’ is now duce tequila with other Agave species in the eastern part of State better spelled ‘mezcal’ to avoid any in other states have failed. Because of (samples dated between 1500 and confusion with ‘mescal buttons’ which their source, all agave spirits contain a 1000 BCE). These take the form of are derived from the infamous peyote significant (0.1-9.7 mg/L) oxalate level. two superimposed globular vessels cactus Lophophora williamsii, a plant Other (sometimes as mes- interconnected by two or three tubes, with psychotropic properties conveyed cals) are made from various species and Needham reckoned that “With by the alkaloid mescaline. The Agave of Agave in different Mexican regions, a cooling-water basin above and a spp. selected for producing mezcals but tequila manufacture is restricted catch-cup inside, such pots could are commonly known as maguey de to the use of blue agave. Tequila is have been used for alcohol distilla- mezcal, Mezcalmetl, or simply mez- NOT distilled from pulque, and should tion in pre-Columbian times”. Today, cales. The basic process for mak- NOT contain the grub of the agave versions of ‘Asian stills’ are used for ing mezcals shows remarkably little moth (‘worm’), although some other artisanal mescal production. regional difference, and varies mainly mescals, such as mezcal de , do. Needham’s hypothesis has been in scale and equipment used – which Such an addition is purely a commer- put to the test by researchers from the varies from pot stills to the huge cial concept and has little or no histori- Yucatan Center of Scientific Research equipment in Jalisco. cal context. and the National Center of Anthropol- Under the banner of ‘mezcal’ the Most of the different types of ogy and History who have successfully most well-known is tequila obtained tequila arise from the proportions of conducted experiments using replicas from plants of the blue agave (A. tequi- agave used, distillation equipment, fer- of Capacha Culture vessels. Results lana Weber var. azul) grown near the mentation microbes, and ageing time. showed that some kind of distillation town of Tequila and other regions in The majority are colourless (‘white’; process may have been known in this the state of Jalisco. The Mexican Gov- blanco), although some premium area as long as 3500 years ago. They ernment established the Denomina- brands are oak-aged and acquire a summarise as follows: “Average gourd tion of Origin (DO) for tequila in 1974, golden hue. ‘Gold’ tequila results from and trifid vessel sizes, their archaeo- and the drink is protected under the the addition of caramel to a white form logical context, and the ethanol yields North American Free Trade Agreement and is unaged. ‘Silver’ tequila ema- of the replicas suggest that, if used (NAFTA). There are two basic catego- nates from a wash containing not less as stills, they were used to produce ries of the drink: ‘100% agave’ and than 51% agave-derived sugars and a prestige product for ceremonial ‘mixed’. should be between 38 and 55% ABV. purposes, with high social and cultural The former stipulates that only Matured are categorised as relevance”. pure agave juice can be fermented ‘aged’ (añejo), which is aged in wooden It should be realized that the above and the product must be bottled in barrels for a minimum of 12 months, aboriginal stills have seen modifica- Mexico. ‘Mixed’ tequila, on the other and ‘rested’ (reposado) which is aged tions made over time. If distillation hand, has up to 49% cane sugar added in wooden tanks or casks for a legal did occur prior to European contact, to agave sap and is usually shipped minimum period of two months. Best- then it was via some ‘primitive’ still out in bulk for bottling in the country quality añejo are aged 18 months to arrangement, as above, but this sort of import. Use of non-Agave sugar was three years for ‘mixed’ samples and up of apparatus was largely replaced sanctioned when blue agave was in to four years for those made of 100% post-Conquest by the ‘Arab serpentine short supply. It requires 6.0 Kg agave agaves. Best quality reposado is aged system’ which the Spanish used to to make 1 L 100% tequila at 55% ABV, 3-9 months in wood (whether ‘mixed’ make rum from sugar cane. Suffice to whereas other tequilas require half or 100% agaves). Silver or blanco tequilas (whether ‘mixed’ or 100% agaves) receive little (no more than 60 days in stainless tanks) or no ageing. A sample designated ‘100% agave’ must not have had water added to agave juice prior to fermentation.

Modern tequilas Artisanal mezcal (including tequila) production process of most commenc- es with the plants being dug up and their leaves (pencas) removed, leaving the ‘heads’ (cabezas), or ‘pineapples’ (piñas), The heads (the ‘hearts’ of Bourke and Lumholtz) are introduced into stone-lined fire pits (stones to retain heat), and covered with organic debris such as leaves, grass, etc. Agave ‘heads’ being loaded into oven (from Valenzuela Zapata & Gaytan, 2012 - by kind permission) This mass is then covered in earth, to

42 z Brewer and Distiller International August 2016 www.ibd.org.uk ALCOHOLIC BEVERAGES l

ensure that no smoke or heat escapes, and left for 1-3 days (depending on Agave reserve polymers oven size and amount of distillate to be made), after which the piñas, now Due to their specialised mode of CO2 fixation (Crassulacean acid metabolism; CAM), soft and golden brown, are removed, fructans (ca. 97% fructose; 3% glucose) are the main products of photosynthesis in Agave crushed and macerated to express spp. and these replace starch as the major food storage compound. Fructans from differ- the sweet juice (‘syrup’ , ‘must’ or ent plant species exist as oligo- or polysaccharides and they accumulate over a period of ‘wort’). With or without dilution, must time to nourish flowering events and to act as osmoprotectants during drought periods. is fermented for 3-7 days to produce In A. tequilana, it takes from 8-12 years to produce fructan levels sufficient for successful ‘mescal wine’, which is then distilled. flowering. It has been shown that in 2-year old plants 69% of carbohydrate is fructan, with The taste of the distillate will largely the remainder consisting of fructose, glucose and sucrose, whereas at 4-6.5 years 97% of depend on cooking time; whether the carbohydrate exists as fructan. Fructans are synthesised and stored in the stem and basal juice is fermented in the presence of leaf tissue (the piña). plant debris (bagasse); still design, ‘Inulin’ is the term applied to a heterogeneous blend of fructose polymers and does and care taken during distillation. ABV not describe one molecule; technically, it is a ‘polydiverse fructan’. Oligofructose is a of this ‘young mezcal’ is normally in sub-group of inulin which has a low degree of polymerisation (<10). Inulin has been part the range 36-55%. of man’s diet for many centuries and has a number of interesting nutritional properties. The first important modifications to It improves organoleptic properties, increases foam and emulsion stability, and exhibits artisanal tequila production occurred fat-like behaviour when in a gel with water. Although present in a number of everyday during the 19th C with the introduction foodstuffs, such as onions, wheat, and banana, it is obtained industrially from chicory. In of brick ovens and copper stills. The fact, inulins are quite diverse, especially in terms of their degree of polymerisation (DP) th 20 Century saw the introduction of and presence of branches. Backbone chains can be entirely of fructose units (Fm) or have autoclaves and the increasing use of fructose chains with terminal glucose units (GFn). Fructan metabolism in A. tequilana mono-cultured blue agaves. Today, the shows changes in its soluble carbohydrate content and DP along its development cycle. tequila industry is a fascinating mixture After starch, fructans are CH OH of ‘old’ and ‘new’, for while one can still 2 the most abundant non- O O OH findpiñas being buried over hot coals, HOH2C structural polysaccharides in OH HO heating usually occurs in brick ovens nature, being found in many HO O or autoclaves. Fermentation can be H2C plants and some bacteria. spontaneous or use commercial yeast OH HO Fructans from the latter are O O strains, while distillation varies from HOH2C HOH2C O invariably of the levan type, HO HO a two-stage pot process to continuous n n which consist almost exclu- flow apparatus with rectifiers. Overall, sively of β(2→6) fructosyl- H2C H2C the modern tequila industry consists of HO HO fructose links. Inulins consist O O three main interest groups; agave farm- HOH2C O HOH2C O mainly of β(2→1) fructosyl- HO HO ers, tequila distillers, and the bottlers fructose units, although in A. and distributors. Supply and demand tequilana the highly-branched CH OH CH OH patterns are complicated, primarily HO 2 HO 2 (24%) inulin contains β(2→6) linkages as well as β(2→1) because the maturation time of blue Projections of GFn inulin-type fructan (L) and Fn inulin-type fructan (R) agave makes cultivation complex. linkages. The general term Post-harvest steps in modern ‘fructan’ is used for any compound in which one or more fructosyl-fructose links prevail. tequila manufacture include: cook- In humans, the β(2→1) linkages prevent inulin from being digested like a ‘typical’ carbohy- ing (steaming) the ‘head’ to hydrolyse drate and thus it has reduced calorific value and mimics dietary fibre. Although heat treat- fructans; milling the cooked heads to ment is considered necessary for the organoleptic quality of tequila, experiments have extract juice; fermenting sugars from shown that extraction and hydrolysis of agave fructans can be carried out continuously by juice; double-distillation of must to using commercial inulinases. produce blanco tequila, and ageing either 3 or 8 months to get reposado or for a further 48 hours. During this to fermentation. This can be overcome añejo tequilas. Tequila production today stage, a sweet liquid (’cooking honey’) by the addition of (usually) ammonium often employs reverse osmosis (RO) is formed (and collected) and some sulphate. Over-cooking also leads to to cut distillate down to sales strength sugars are caramelised. Alternatively, increased levels of furfural, 5-hydroxy- (usually 40-50% ABV), and the use of agave is autoclaved by injecting steam methyl furfural, and 5-methylfurfural, activated charcoal/cellulose to remove for 1 hour (to wash agave) and then which affect fermentation and the the haze caused by solubilisation of adding more steam to reach 121°C, organoleptic properties of tequila. the waxy cuticle of agaves during after which steaming ceases and the Autoclaving permits better control of fermentation and distillation. Bagasse contents remain sealed for six hours. cooking and thus decreased likelihood represents ca. 40% of the total weight During cleaning, a bitter liquid is pro- of over-cooking, of milled agave, and would contain ca. duced which is discarded. After either During spontaneous tequila fer- 43% cellulose; 19% hemicellulose, method, agave is cooled and then mentations non-Saccharomyces yeasts, and 15% lignin. It has uses as a biofuel milled for juice extraction. such as K. marxianus and Kloerckera feedstock. When piña are cooked (or, over- apiculata, often ‘outperform’ Sacch. Head fragments can be cooked in cooked!), most of the assimilable nitro- cerevisiae. They show higher osmotic an oven by steam-injection for 36-48 gen disappears due to participation in and ethanol tolerance and produce hours at 100°C, after which time steam Maillard reactions, thus making the more essential volatiles. Accordingly, is turned off and the load left enclosed juice poor in available nitrogen prior these species are often constituents www.ibd.org.uk Brewer and Distiller International August 2016 z 43 l ALCOHOLIC BEVERAGES

of any industrial inoculum. Agave juice Minor components include other alco- just prior to them undergoing sexual expressed during milling is normally hols, aldehydes, ketones, large-chain reproduction – which does nothing for diluted down to ca. 1.058 SG before ethyl esters, organic acids, furans, plant vigour. Blue agave, for example, fermentation. terpenes, alkenes, and alkynes. Many is mostly propagated by vegetative Over 175 components have been of these are common to tequila, but (asexual) means and this has re- identified in tequila, some 60-odd be- unique to mezcal are limonene and sulted in reduced genetic variability ing associated with aroma – the most pentyl butanoate. and increased disease susceptibility. significant being iso-valeraldehyde, Related beverages are the mezcals Although most Agave species cross- iso-amyl alcohol, β-damascenone, raicilla, , and bacanora, pro- pollinate and often hybridise, many can 2-phenyl ethanol, and vanillin. As a duced in different regions of Mexico. propagate by vegetative means (bulbils group, after ethanol, esters, most Raicilla, thought to have originated and suckers). notably ethyl esters, are the most pre-Conquest, uses A. maximiliana and The present level of production abundant volatiles in tequila and they A. inaequidens (the ‘mule foot’ aga- of many agave distilled beverages show marked quantitative and qualita- ves), which are smaller than the blue may become tenuous because of the tive differences according to tequila agave used for tequila manufacture. It occasional shortfalls in raw material type. Ethyl esters are produced during is indigenous to western Jalisco and availability and/or species demise. fermentation and during ageing, and is described as ‘smoother’, ‘smokier’ Over the past few decades, for exam- so aged tequilas thus contain the high- and ‘more fruit-forward’ than tequila, ple, mass cultivation of blue agave est levels. Ethyl esters common to all but taste varies with distillery location. for industrial tequila production has tequilas are: hexanoate, octanoate, de- Sites near the coast yield a ‘smokier’ caused soil erosion, chemical pollu- canoate, dodecaoate, tetradecanoate, drink which shows more ‘tropical tion, and the displacement of agaves hexadecanoate, and octadecanoate – fruit’, whereas in those from the sierra used for making other mezcals. Thus, with the last two being the most abun- ‘citric’, ‘wood’ and ‘peppery’ notes in some areas, there is a danger of dant. It has been proposed that ethyl prevail. Alcohol content varies from losing the 10,000-year old Mexican esters could be used to ‘type’ tequila 35-45% ABV. agro-biodiversity and replacing it by a samples. Sotol, a speciality of the northern commercial monoculture. states of Chihuahua, Coahuila and Related beverages , is made from the agave- • The author wishes to thank Dr. Following tequila’s appellation of ori- like ‘desert spoon’ plant (Dasylirion Patricia Lappe-Oliveras (Photographs; , the other Agave spirits have been wheeleri). It is made in the same preparation of pulque, page 40), Dr granted equal recognition. At pre- manner as mezcal, and for years were Ana Valenzuela Zapata (Photographs; sent, only tequila, and, more recently, regarded as an ‘inferior’ drink only Asian still and agave heads, pages mezcal are the only agave spirits to produced when mezcal agaves were 41and 42), and Patricia Colunga- be produced on an industrial scale unavailable. Bacanora is an artisanal GarciaMarin for their help with this and to have international recognition. spirit produced in state and article and for permission to use Mezcal, itself, is most closely associ- uses wild A. angustifolia the most eco- previously unpublished photographs. ated with the state of Oaxaca and its nomically important Agave species in manufacture uses the juice of other Sonora. The plant is initially processed References Agave species, such as A. angustifolia, à la tequila. After agave grinding and Bourke, J.G. Primitive distillation among A. salmiana, and A. potatorum. addition of water, the spontaneous the Tarascoes. American Anthropologist 6: Production is more ‘rudimentary’ fermentation takes 7-14 days accord- 65-70. 1893. than that for tequila inasmuch as ing to temperature. Juice and bagasse Lappe-Oliveras, P. et al. Yeasts associated both juice and bagasse are usually are distilled once, after which the with the production of Mexican alcoholic spontaneously fermented. Basically, latter is removed. A second distillation non-distilled and distilled beverages. FEMS agave piñas are roasted, shredded and yields three fractions that are blended Yeast Research 8: 1037-1052. 2008. Lumholtz, C. Unknown Mexico, Volume II. mashed; fermentation and distilla- uniquely by each distiller to give Charles Scribner’s Sons, New York. 1902. tion follow. Each Mexican state makes alcohol contents between 38 and 55% p.182-185. online its own kind of mezcal, and, in recent ABV. Bacanora distilling was banned Needham, J., et al. Part IV. Spagyrical times, the demand for these drinks between 1915 and 1992, although it Discovery and Invention: Theories and Gifts, has mushroomed. survived via clandestine distilleries. in Science and Civilisation in China. Vol. 5, During the production of mez- Since 1992, popularity of the drink has Alchemy and Chemistry, J. Needham (ed.). cal from A.salmiana, the microbial increased considerably and this has Cambridge University Press, Cambridge. consortium responsible for sponta- led to the exploitation of A. angustifolia, 1980. neous fermentation is dominated by which is now in need of conservation. Valenzuela Zapata, A.G., and Gaytán, M.S. bacteria, mainly LAB and Z. mobilis, Sustaining biological and cultural diversity. the latter also being characteristic Serious over-harvesting Geographic indications and traditional of pulque fermentation. Also present Since the end of the 19th century, the mescal production in Jalisco, Mexico. Revue d’ethnoécologie 2. 2012. (electronic) are the yeasts Clavispora lusitaniae, popularity of mezcal drinks, particu- Zizumbo-Villarreal, D., & Colunga- Pichia fermentans, K. marxianus, and S. larly that of tequila, has, together with GarcíaMarín, P. Early coconut distillation cerevisiae. The bacteria and the non- an increased demand for fibre, placed and the origins of mescal and tequila spirits Saccharomyces yeasts contribute sig- a strain on the plant communities in west-central Mexico. Genetic Resources nificantly to the production of volatiles where agaves grow. The potentially and Crop Evolution 55: 493-510. 2008. in mezcals, which consist principally of serious situation of over-harvesting is Zizumbo-Villarreal, D., et al.,Distillation in saturated alcohols, ethyl acetate, ethyl exacerbated by the fact that, by defini- Western before European 2-hydroxypropanoate, and acetic acid. tion, plants are taken for processing contact. Economic Botany, 63: 413-426. 2009

44 z Brewer and Distiller International August 2016 www.ibd.org.uk