Production

Patrón may be one of the largest tequila brands yet it remains one of the most artisanal with 1,800 people working at Hacienda del Patrón, its distillery.

Although volumes are massive, the brick ovens, wooden fermenters and copper stills are all tiny – there are just a lot of them. Instead of building bigger ovens, fermenters and stills, or increasing the batch size, Patrón has increased production capacity by exactly replicating its original small batch process designed by Master Distiller, Francisco Alcaraz. Hacienda Patrón now houses multiple small distilleries under on one site with another, again a clone distillery, in the centre of the small town of Atotonilco El Alto nearby. And the construction of more small clone distilleries looks set to continue.

Production of Patrón starts with Weber Blue Agave, sourced locally from the Highlands of Jalisco. The distillery was sited here to ensure plentiful freshly harvested agave coupled with the quality and mineral content of water. Patrón prefers agave grown in the Jalisco Highlands to those gown in Tequila Valley due to the cooler temperatures at this altitude, higher annual rainfall and the iron oxide rich red soil, which all contribute to Highland's agave a higher sugar content – a major contributor to the quality of the finished tequila.

Unlike many tequilas which add sugar to stretch production (mixto tequilas), all Patrón tequilas are made with all the fermentable sugars coming exclusively from agave. Hence, they are termed "100% agave tequila" with every bottle certified as such with the Mexican government's CRT certification symbol. The labels also carry a four-digit DOM number 1492, a guarantee that all Patrón tequila comes from Hacienda del Patrón.

Agave

The piña is the heart of the agave plant and in the case of Patrón, and other 100% agave tequilas, this is the source of all the sugars used in the fermentation. Patrón ensures a continuous supply of high-quality piña by having long-term contracts with its suppliers, mostly family-owned farms.

Importantly, Patrón has strict quality requirements for the piña they buy. Those not meeting these requirements are rejected.

• Patrón demand that only agave at its peak ripeness is harvested, between 6 and 8 years old, to produce the sweetest and most flavoursome mosto possible.
• The ripeness of the agave ensures a minimum sugar level of 21%. Interestingly, while the industry average sugar content is 21%, Patrón's average is closer to 25%.
• Patrón specify that the jimadors closely trim the leaves off the piña to ensure that the waxy leaves don't adversely affect the flavour of the tequila.
• Despite the loss in weight resulting from such close trimming of the piña, Patrón require that the minimum weight of each piña received at the distillery is at least 10kgs, this requirement is for safety reasons as more accidents occur when trying to spit very small piña on the patio prior to loading the ovens. (6kg of piña is required to produce one litre of tequila.)
• When the piña are cut into four segments on the patio in front of the ovens at the distillery, the Cogollo of Novillo agave is removed. Like the core of a pineapple, this is tough and would add a bitter flavour if left in place.
  
• Although Patrón specifies ripe agave and rejects overripe agave due to the vinegar-like notes these bring to the tequila. While red spots, a sign of ripeness are desirable, any more than seven per piña is unacceptable.

The axes used to cut the agave are kept razor sharp

Cooking the piña

Prior to being hand-staked in the ovens, the piña are cut into four segments to ensure a thorough uniform bake. This steam baking process converts starches in the piña into fermentable sugars. A slow roast and prolonged cooling period are key to attaining the desired flavour profile. Undercooked piña have little flavour and less fermentable sugars while overcooked piña are bitter with burnt patches preventing yeast activity. Perfectly cooked agave are juicy, fruity and sweet.

loading an oven

Patrón slow roast in small traditional brick ovens and it is at the oven stage that the differences between the two parallel production processes at Patrón start. The ovens supplying the Tahona mills have a 14 tonne capacity, while those supplying the roller-mills have a 24 tonne capacity. Both sizes of oven have the same long 79-hour cooking time split between steam heating followed by a slow roast period without steam and final resting and cooling period with the oven opened to vent.

Sweet agave syrup (agave honey) is collected from a channel in the bottom of the brick ovens and Patrón only collects the purest agave syrup from the last 6-7 hours of cooking. The roasted piña are unloaded from the ovens by hand and then sent, via conveyor belts, to one of two different crushing processes at Patrón.

Crushing the piña

Patrón is one of only nine or so tequila producers we know of still using traditional Tahona Mills to crush piña. Indeed, Patrón's Tahona wheels (10 in 2007) outnumber all those of the other distillers' Tahonas combined. The distillery also uses more modern five-step roller-mills and the two different types of mill produce the two distinct styles of tequila that are blended to make Patrón.

The roller-mill machines crush and squeeze cooked agave from the 24 tonne brick ovens to release its sugary juice. As the agave fibres move through the mill, they are sprayed with water to wash more of the precious juice from the fibre and this sweet mosto is sent to a holding tank where it's mixed, aerated and the sugar content tested. If the brix (sugar content) is too high then water is added, and if too low then agave honey from the ovens is added. When the perfect brix for fermentation is attained then the mosto is sent onto the fermentation tanks.

Roller mills

Meanwhile, quite separately, cooked piña from each of the 14-tonne brick ovens is evenly split between two Tahona pits to be crushed using the traditional Tahona stone mill method. In this process, agave fibre is pressed between a two-ton Tahona volcanic rock millstone and the riverbed stone floor of a circular pit with the stone being propelled slowly around the pit by a mechanised arm. This slow, three-hour process releases juices which are then reabsorbed by agave fibres. The juice saturated fibres are loaded onto a conveyer by hand and sent to the fermentation tanks.

Tahona pits

Fermentation

The Tahona crushed agave and roller-mill crushed agave both go through long different 72-hour fermentation processes and these long fermentations are key to producing flavoursome congeners during distillation. Although the fermentation time is the same and both Tahona and roller-mill fermentations are in open-topped pinewood fermentation vessels, there are several key differences:

- The Tahona milled juice is fermented in small 5,000 litre vessels while the roller-mill juice ferments in 10,000 litre vessels. (Even these larger fermenters are tiny compared to those used by most other major tequila distillers.)

- Unlike the roller-mill fermenters which only hold mosto (agave juice), the Tahona crushed agave fermentation includes both mosto and bagasse (juice saturated agave fibre). The activity of the yeast helps drive the fibres to the surface where they float and form a crust that creates a partial seal.

- The inclusion of the fibre from the Tahona mill produces a richer tequila with an earthy, herbaceous, baked agave flavour, while the roller-mill crushed agave produces a more citrusy tequila.

5,000 litre capacity fermenter filled from Tahona mill capped by agave fibre

10,000 litre capacity fermenter filled from roller mill without fibre

The pinewood the fermentation vessels are made of imparts no flavour but the wood's pores harbour microbes and importantly the wood helps insulate against temperature extremes. These traditional wooden fermenters need replacing every five years so are expensive to maintain as well as being labour-intensive to clean between fermentations. Hence, most other major producers use stainless steel fermenters.

Water

The acidity of the water and its mineral content are critical to the fermentation process and so the flavour of the tequila. Patrón's water is drawn from a deep aquifer located below the distillery site (one of the factors that influenced the distillery's location). The water is naturally soft and has a consistent mineral balance perfect for tequila production.

There is a subtle difference between the water supplying the main distillery and that supplying nearby Casa Patrón, hence both roller-mill tequilas are blended along with the Tahona tequila in the finished product.

Yeast

Patrón is made from just three ingredients: agave, water and yeast – all three greatly influencing the flavour of the final tequila but Patrón say that yeast contributes as much as 70% of the tequila's flavour, hence they are in full control of their yeast.

Most other tequila distilleries buy their yeast from third-party suppliers or take the chance on naturally occurring air-bone and surface yeasts. However, Patrón propagates their own proprietary yeast strain, originally found naturally on agave plants, using a three-stage propagation process moving to ever-larger propagation vessels, every 24 hours, as the number of yeast cells multiplies: 450 litre to 4,500 litres and finally 10,000 litres.

This yeast is key to the flavour of Patrón so to ensure continuity yeast cultures are cryogenically stored (at -80°C) cultures – one on-site and two externally.

Distillation

As with other aspects of the production process at Patrón, the pot stills are tiny compared to most tequila producers and are constructed from copper rather than the cheaper, longer-lasting stainless-steel stills used by many others. The benefit of copper is that it reacts with alcohol vapours in the still to sacrificially remove bad-tasting sulphur from the distillate. All the stills are steam-heated via copper serpentines in the base of each still.

As with proceeding processes, the small-batch distillation at Patrón differs slightly between the Tahona and roller-mill sides of the distillery.

In the Tahona distillation, the first primario distillation takes place in 750 litre capacity still and takes two hours. This Tahona distillation is with both mosto (agave juice) and bagasse (juice saturated fibre). Patrón is one of only a handful of distilleries to use fibre in the distillation process. The second Tahona distillation is in an even smaller 550 litre capacity still.

The roller-mill copper pot stills are larger with the first distillation in 2,500 litre stills (without bagasse) and second distillation in 1,500 litre stills. The size and shape of all the stills is according to the original exacting specifications demanded by Master Distiller, Francisco Alcaraz.

As the mosto, which is around 4% alc./vol. heats up and boils, different alcohols and compounds flow from the condenser, firstly the 'head' consisting of unpleasant highly volatile alcohols and lastly the 'tails', consisting of oils and other less volatile compounds. Between the heads and tails flows the all-important 'heart' and it's down to the distiller operating the still to judge when to make the cuts to divert the flow to send unwanted heads and tails to one vessel for recycling and the heart to another tank to be store before going onto the second distillation.

The heart of the first distillation produces a distillate of around 25% alc./vol. and during the second distillation, this is rectified to 55% alc./vol., again only selecting the middle 'heart' of the run. Heads and tails from both first and second distillations are recycled and mixed with the mosto to charge the next first distillation.

Distiller assessing when to cut from heart to tails.

The distillers operating the stills do not use computers to decide when to cut from heads to hearts and hearts to tails, instead, they rely on experience, thermometers and hydrometers. Consequently, these are the most experienced people who graduate to their position after working for years in other parts of the distillery.

Hydrometer and thermometer used by distillers to test alc./vol. during distillation.

Like most other tequilas, Patrón tequilas are double-distilled, except for and Gran Patrón Platinum which are triple-distilled.

Blending

After roller-mill and Tahona distillations have been filtered they are blended to make Patrón Silver and reduced from 55% alc./vol. to bottling strength with de-mineralised water. Or, alternatively, the blended tequila goes into cask to become one of Patrón's rage of aged tequilas.

I have badgered folk at Patrón for the percentage of Tahona distillate to Roller-mill distillate used to blend Patrón's core range of tequilas, but this is a closely guarded secret. Based on production capacity, my guess is this is somewhere between one-third to two-thirds and equal parts.

Remember, Patrón's Piedra and Roca tequilas are made only using Tahona distillate but even these require careful blending between casks.

Aging

Patrón tequila's (with the obvious exception of their unaged Silver tequilas) are aged anywhere between a minimum of three months for Patrón Reposado to seven years for Añejo 7 Años and are aged at high proof - 55% alc./vol.. A bewildering range of different cask types are used, all of which are toasted:

Patrón's core range Reposado and Añejo tequilas are aged in five distinct cask types:

1. New wide grain French Limousin oak
2. New French Allier oak
3. American oak ex bourbon barrels
4. New American oak barrels
5. New Hungarian oak

Aging period & cask type

Patrón Silver - unaged
Roca Patrón Silver - unaged
Gran Patrón Platinum - rested 30 days in oak tanks
Patrón Reposado - aged 3-5 months in combination of 5 cask types above
Roca Patrón Reposado - aged 4-6 months exclusively in ex-bourbon barrels
Patrón Añejo - aged 12-15 months in combination of 5 cask types above
Roca Patrón Anejo - aged 14-16 months exclusively in ex-bourbon barrels
Patrón Gran Burdeos - aged 2 two years (1 year in ex-bourbon barrels, 10 months in French oak barrels, 2 months finishing in first-growth Bordeaux wines barrels)
Patrón Extra Anejo - 3 years in combination of 5 cask types above
Gran Patrón Piedra - aged 3 years in French and American oak

There is no temperature or humidity control in Patrón's barrel houses and due to the high temperatures some 12% volume is lost from the maturing tequila per year due to evaporation.

The barrels are traditionally stacked eight high in rows rather than palletised and once positioned in their row, the casks are not moved until they need replacing. The casks are emptied and filled through the bung holes on the top of each cask (which are bunged with synthetic rather than wooden bungs) with the tequila either pumped into or out of each cask while in situ.

Blending

The size and type of cask, type of wood (American oak, European oak or Hungarian oak), type and number of previous fills, location, temperature and humidity all influence the flavour of the aging tequila. Hence, blending the contents of different cask types is essential to attain the desired consistent character of the finished tequilas.

100% agave tequilas are permitted up to 1% additives (caramel, sugar, glycerine and boise (oak extract) but unlike numerous other tequila distillers, Patrón don't add any additives, not even caramel for colour correction. Instead, Patrón achieves colour consistency through blending.

Bottling

After blending Patrón tequilas are reduced to bottling strength with distilled water. Everything at the distillery is handcrafted and unusually, this continues through to the bottling line where the filling machine, necessary to ensure every bottle has the correct volume, is the only mechanised part of the process. Every bottle is hand-corked, hand-labelled and hand-wrapped. Patrón says that at least 60 hands touch each bottle before it leaves the distillery.