The Dirty Truth Of Making Mezcal And How We Can Do Better

Richard Betts
10 min readMar 16, 2017


It’s been eleven years since we started on the journey that is Sombra Mezcal, and I feel now is an ideal moment to pen a letter to both the community of producers and to mezcal lovers around the world. Here I’ll share some of the things we’ve learned along the way, and even more importantly, the direction we’re headed with an invitation for others to join us.

Over the past eleven years we have worked in a number of villages with a number of families, in each instance aiming to do better work, to learn more and then to put those lessons into practice. This has taken us from San Luis del Rio to San Juan del Rio, to working simultaneously in both communities and finally to Matatlan. Along the way we’ve made many friends, we’ve made some great mezcal, and happily, we’ve made a positive economic impact in each community. We’ve also had a growing list of hopes and aspirations for how we want to make Sombra Mezcal consistently better and better. The accrual of these hopes and aspirations has dovetailed with an enormous surge in interest in mezcal and a proliferation of new brands. What was once the province of just a couple brands and many small family operations is now host to a great many brands which have captured the attention of both consumers and multinational spirit companies.

No matter how you look at it, mezcal has become an industry and is now a defined and measured spirits industry ‘category’, the same as Tequila or Whiskey, for example. Thus it is more important than ever to acknowledge the responsibility we’ve inherited. If we are to honor our communities as well as the land, we must pave the way for healthy, responsible growth by fostering practices that take care of Oaxaca, a place and a people that many of us have come to deeply love.

What this means for Sombra, as well as for myself, is taking a good, hard look at ‘tradition.’ In the marketplace ‘tradition’ is a positive attribute and it along with ‘authenticity’ are most frequently referenced as positive selling points. This makes sense. The attachment of the spirit to a people, a place, a geology, geography, a history and a cuisine: this is what makes mezcal so special.

But it is also no longer good enough.

Our industry, the spirits industry, is full of amazing, smart, capable and creative people. It is also an industry of fun, and sometimes in the midst of this fun we forget to get to the heart of the matter and ask the important questions. For us at Sombra, rather than taking the notion of tradition at face value, we have opted to dissect it further. We’ve evaluated ‘tradition’ for its environmental impact, its sustainability, and its ethical considerations. In doing so, we have arrived at a vision for a brand new, 21st century palenque (distillery). We believe it is the future of thoughtful, environmentally friendly production (that also happens to makes great mezcal).

Here, step by step, are the broad strokes of what we’ve done and how it’s working. We’ve been distilling here for only a few months and the results are very encouraging.

Raw Espadin agave waiting to be roasted.

Once the agave are harvested, the first step in creating a mezcal that properly respects place and tradition is the roasting of the agave over a wood fire in a stone pit. We believe this is essential and informs the spirit in a profound way. The type of wood one uses and the length of the roast are important factors but no matter how you do it, you’ve got to roast with wood. We’re working with only certified wood from sustainable wood farms in San Miguel Cajonos. These certified farms are rare in the industry but they matter because, like any natural resource, the forest needs to be managed to ensure its future. We’re hopeful that our use will encourage others to follow suit. Additionally, we’re investigating further reforestation measures as well as working to offset the CO2 impact of our travel to and from Oaxaca via both agave and additional tree planting.

Post-roasting, the horno (oven) is still hot.

Once you’ve roasted and unearthed the agave, you’ve got to grind them prior to fermentation. Traditionally this is done with a horse-turned millstone. We do believe that the grinding step is essential, however we do not believe the actual horse is necessary. I understand that many animals are domesticated for work purposes, but having seen a great number of unhappy, unhealthy horses and donkeys used in mezcal production, we’ve decided to set the horse free and mechanize the turning of the tahona. Same tahona, same grinding process, same end result, and all from an electrically turned millstone. We (and our horse) see this as a very positive thing.

Roasted agave waiting to be crushed.
Mechanical Tahona at work.

Now it’s time to ferment the roasted and ground agave. Traditionally this is done with native yeast, as the yeast colony grows slowly thereby providing plenty of time to extract flavor from all of the ground agave. This makes sense and is a piece of the process that, while it takes more time than commercial yeasts or additives, we believe is worth preserving, therefore it’s standard practice at our palenque. There is, of course, much more to fermentation that just using native yeasts (there are many approaches with regards to duration and temperature), and these decisions are part of what make any mezcal unique. Bottom line: using a native ferment that proceeds over the course of a week or so respects an important aspect of tradition and is a crucial step in making great mezcal.

Ground agave liquids and solids in their fermentation vessel.

From here we take our fermented agave (liquids and solids) and run them through the first distillation. Traditionally the stills are fired with wood. It’s certainly a remarkable thing to watch someone hone a wood fire just so and to coerce mezcal out of the still. But it’s important to really evaluate what’s happening in this process. Considering that the still is a closed system (meaning that no flavor is imparted by the wood fire), the wood is merely a heat source. So if the source of the heat doesn’t matter, why not choose a cleaner source?

Instead of contributing to deforestation as well as adding more CO2 to the atmosphere by burning wood, we’ve chosen to work with some of the brightest minds in Oaxaca to arrive at a specific propane gas system that is an especially efficient and responsible heat source. This doesn’t mean simply turning up a gas flame under the copper still, it means adding the exact amount of extra oxygen not available in the environment to the propane, which then squeezes every tiny bit of energy out of it. (This air to fuel ratio is further described here if you’re interested.)

We’ve also taken additional care with the insulation of the stills so that only a small amount of gas is actually used and maximum heat is retained. The result? We’re saving trees, distilling with better precision, making something more delicious and more consistent, and all with less waste, which is so important. Add to this the enormous benefit of cleaner air so our mezcaleros are not breathing smoke all day, which we all know is detrimental to one’s health. (If you’d like to read more about the impact of word burning you can do so here.)

Construction and insulation of two of our stills.

Of course when we’re distilling it is very easy to get distracted by the good stuff coming out, but it’s as important not to forget about what is left behind inside the still. If you imagine our fermented agave is plus or minus 5% alcohol, and we are distilling to roughly 60% alcohol, there is clearly a great deal of material left behind. In fact, for every 0.750 liter bottle of mezcal, there are roughly 10 to 12 liters of vinasa (the liquid left behind) and 15 to 20 kilograms of bagazo (the spent agave fibers) left behind, and as you’ll see, this leftover material is pretty noxious stuff.

Traditionally, most palenque are built on rivers; this has served several purposes. Positively, the river provides water, vital for both the fermentation process as well as cooling and condensing the distilled alcohol vapor. What’s less often talked about is how the wastes are actually cleaned out of the still: by simply shoveling them alongside and into the river. Apart from its physical mass, this waste is both acidic and oxygen-starved, so when it leaches into the rivers that palenque are built on, it negatively affects the environment in two ways. First, it absorbs a great deal of oxygen from the water. This is the same oxygen that all of the fish and other aquatic life count on for survival. Second, its high acidity lowers the pH of the water, making it potentially unsuitable for drinking in those communities once dependent upon the river for potable water.

For our part, we are exploring three different options for how to effectively deal with the by-product of distillation. First, we’re taking a cue from the tequila industry which has developed a method of spreading, spraying and aerating the bagazo and vinasa to safely allow it to decompose into compost. This of course takes time and space, but it’s meaningful to do. Second, we’ve begun to make adobe bricks hydrated with some of the vinasa and reinforced with spent bagazo. The process is one of hydraulic compression which makes them stronger than traditional adobe bricks and, at peak, we’ll make up to 700 bricks per day. We’re experimenting with these bricks for a few building projects at the palenque, and if everything works as planned, we’ll eventually be able to contribute these bricks to public works in our community of Matatlan. Finally, we’re investigating the feasibility of using this waste from the distillation as biofuel for the stills. If successful we’ll be able to replace much of the propane gas we’re currently using. This is an exciting possibility and we’ll be communicating our results as we go.

There’s also the question of water supply. It’s needed for fermentation as well as the condensation coils, so while building the palenque, we installed three underground tanks which have captured 100,000 liters of rainwater collected from the roof. At this point much of the water we utilize comes from the sky.

The new Sombra Palenque in Matatlan, Oaxaca.

Electricity is essential too — remember, we set the horse free. Here we’re also looking to the sky, therefore we’re in the process of installing solar power on the roof of the palenque. There are few better places on earth for solar power than Oaxaca, which enjoys more than 300 days of sunshine per year. Eventually, we expect to generate more than enough electricity to run the entire palenque. It’s exciting.

Finally there is the element of our Oaxacan community. Like many producers, we’ve seen the growth of Sombra put meaningful funds into the communities where we work. This is thrilling, and it’s only spurred us to do more. For nearly two years we’ve been sponsoring and facilitating educational classes in our community of Matatlan. Today we are teaching both reading and writing in native Zapotec, Spanish and English. We’re also teaching photography. The classes are warmly welcomed, with more that 40 children attending each week. These children are also able to apply for a grant that covers travel to the U.S. for an entire summer of learning English. It’s one additional effort to help build bridges instead of walls. One must do good while trying to do well, and it feels great to be able to give back to our community here.

All in all, these are the broad strokes of our vision to help the mezcal industry grow in a responsible way that does right by Oaxaca and her people. While we understand that all of these steps may not be practical for every producer, we do believe that at the very minimum, dealing responsibly with the waste products is essential for any conscientious producer and we encourage everyone to join us in doing so.

Please know that we at Sombra will be sharing our findings as we go. We intend to operate our palenque as an open book; we invite everyone to learn from what we’ve done right as well as where we’ve made mistakes. It is in this spirit that we believe everyone will share in growing mezcal in a responsible way.

Thank you,

Richard Betts

Founder, Sombra Mezcal



Richard Betts

Current: Komos Tequila, Superbird Paloma, An Approach To Relaxation. Past Founder Sombra Mezcal. NY Times Best-Selling Author.