The Secret to Volcano Coffee
How a unique self-evolving soil ecosystem once vital for humanity now co-creates the most spectacular coffee.
Coffee is transforming, morphing from being the center of a mostly mundane morning ritual into something much more special and profound. A shift in discourse is at play; from being sought after merely as a morning pick-me-up, the coffee experience is evolving into an opportunity to explore a complexity of taste that until not too long ago got lost in mediocrity. Third-wave coffee, as it is often called, catalyzes the quest for the best coffee we can create, and among those beans, many come from El Salvador. There is a reason for that: volcanoes.
Panamanian Geisha, Jamaican Blue Mountain, Hawaiian Kona, Ethiopian Yirgacheffe, Costa Rica Tarrazú, Guatemala Antigua, Salvadoran Pacamara, Sumatran, and Kenyan coffee are some of the world's most valued coffee varieties, all sharing a common trait: their proximity to volcanoes. But what makes volcanoes the perfect companion for coffee cultivation?
Coffee Plants Are Picky
The coffee plant is particular about its growing conditions, and volcanic regions have for centuries ticked just about every single box coffee beans could ask for.
Altitude is the first factor that significantly impacts coffee quality. Higher elevations slow down fruit ripening, allowing the flavor to concentrate within the beans. High-altitude coffee often exhibits heightened aroma and acidity compared to low-altitude varieties.
The slow maturing of high-altitude coffee leads to the synthesis and accumulation of oils and fatty acids with larger molecular chains. These macromolecules are detected during tasting and come across as a more intense, acidic taste. Low-elevation coffee plants offer a milder, more restrained flavor profile due to their quickened maturing.
Nevertheless, providing the precise tropical weather, high elevation, and ideal temperature range is at times not enough for the coffee plant to thrive optimally. The secret to producing exceptional coffee lies in none other than the volcanic soil itself. What does this soil convey to the coffee bean, and what does it take to offer such unique growing conditions?
Let us delve deeper and explore the profound implications of volcanic soil not only on coffee production, but also on the development of human civilization.
Millions of Years of Evolution Feed Volcano Coffee
The composition and physio-chemistry of soils in volcanic regions is understood to play a crucial role in determining the quality of your coffee. Well-drained soils are essential for consistent growth and maturing of coffee cherries, preventing stress reactions that lead to undesirable flavors. The porous nature and stability of these soils promote healthy coffee plants, translating to vibrant, aromatic cups of coffee.
Such desired soils can be described as sandy soils, containing both sand as a key component to drain the water quickly, but also silt and clay to provide cohesion among soil particles, lest the rain and wind blow it to dust.
Such a blend of sand, clay, and silt is achieved through the weathering of solidified magma fields. The resulting richness of the surrounding terroir depends greatly on how the magma, ash, and volcanic debris break down and are incorporated into a blend of rich, fertile soil. A whole array of different types of soils can be produced from different volcanoes, resulting in different magma chemistries.
With the sand (mostly silica) providing optimum water management, the silt and clay play second fiddle, retaining nutrients exceptionally well due to their inherent chemical structure such as sodium, potassium, and iron—courtesy of the eroding and chemically decomposing ash and cold volcanic rock. As a result, soils rich in clays (also called Ultisols) do not require as much fertilizer as other types of soils do.
Nevertheless, clay content must not be too high, as this will eliminate the effect of the sand, decreasing water filtration. It is in the surrounding volcanic areas in which this optimum soil balance of sand, clay, and silt is achieved.
As coffee plants absorb the elemental nutrients in these soils, the minerals directly impact the taste profile of the beans, influencing acidity, sweetness, aroma, and overall complexity. The mineral composition of the soil also affects the chemical makeup of the fatty acids within the coffee cherries, which in turn significantly impacts the flavors and aromas of the final product.
However, volcano coffee has another critical ingredient: volcanic glass. This chemically and physically unstable component, formed from rapidly cooled ash particles, gradually decomposes, releasing its minerals and soluble salts into the surrounding soil. These minerals become available to the coffee plant, promoting healthy growth and contributing to the unique flavor profile of volcano coffee.
Nitrogen, iron, and magnesium convey an inherent tangy acidity, sweet fruitiness, and hints of chocolate or caramel to the final brew, whereas iron and copper tend to enhance chocolate notes, and boron relates to fruity flavors. Other important components include potassium, magnesium, zinc, and sulfur.
The Power of Volcanic Ashes
Yet the magic does not end there. Volcanic soils also possess the extraordinary ability to store and preserve organic carbon. This occurs through the deposition of thick layers of volcanic ash, which blankets the area surrounding the volcanoes during and after eruptions.
This layer of ash effectively isolates organic matter from the surrounding oxygen, inhibiting microbial decomposition and preventing its eventual breakdown into CO2. One striking example of this preservation is the eruption of Vesuvius, which covered the nearby Roman town of Herculaneum (now in Italy) with meters of thick volcanic ash.
This unique property of volcanic soils not only contributes to the richness and fertility of the surrounding terroir, but also plays a crucial role in the long-term preservation of organic matter. At this particular site, almost 2,000 years later, forensic anthropologists found exceptionally preserved brain cells of a young man killed and buried by the volcano’s eruption in 79 AD.
Another example can be found at Joya de Cerén, a site in El Salvador where a similar volcanic eruption in around 500 AD buried a vast amount of organic material under thick layers of volcanic ash from the Ilopango volcano's eruption. Remarkably, this material has been found in exceptional condition over a millennium later.
Among the unearthed findings, researchers discovered well-preserved artifacts such as bean-filled pots, sleeping mats, animal remains, and religious items, which would typically degrade rapidly in tropical conditions.
Joya de Cerén also revealed distinct plant remains, including young and mature maize plants, a garden with a variety of herbs, a henequen (agave) garden, and various fruit trees like guava and cacao. These findings provide a unique window into the lives of the people who inhabited this area centuries ago.
Overall, there is strong evidence that suggests volcanic soils form a unique, fertile profile capable of efficiently capturing and retaining a mix of organic and inorganic nutrients. This remarkable soil continuously fertilizes itself and evolves through three distinct mechanisms:
- Weathering and the break-up of surrounding volcanic rock
- Efficient capture of the minerals leached from degraded rock
- Blanketing, capture, and preservation of organic material acting as fossil fertilizer
These exceptional features of volcanic soil extend far beyond the coffee plant, benefiting a wide range of crops and contributing to the prosperity of human settlements. In ancient times, when humans transitioned from nomadic tribes to settled communities, volcanoes were thought to have been beacons of fertility, signaling the ideal locations to establish new settlements.
Humans Used to Settle Near Volcanoes
Archaeological evidence suggests that early human settlements were often established in close proximity to volcanoes. The implications were profound; the correct choice for a settling spot could well have marked the difference between human survival or extinction.
The fertile soil generated by volcanic eruptions provided an ideal environment for agriculture, allowing human communities to thrive. Additionally, volcanic rock was a valuable resource for tools and construction materials. Many ancient civilizations, such as the Maya and the Minoans, were situated in volcanic regions.
Through experience and empirical knowledge, ancient humans likely learned that proximity to volcanoes would ensure a steady supply of both surface water and fertile, renewing soil. This discovery enabled the formation of creative, sedentary communities, in contrast to mere survival through hunting and gathering.
Even today, the influence of volcanoes on human settlement patterns is observable. People continue to live in close proximity to volcanoes, drawn by the benefits these areas offer while acknowledging the potential risks and trade-offs associated with volcanic proximity.
Volcano coffee, nurtured by fantastically endowed soil, is a powerful catalyst of the human experience. It is a beverage that triggers deep human connection–with those closest to you or with those whom you seek to approach. The rich complexity of the best coffee, born from such exceptional soil, transcends its status as a mere hot beverage, becoming a symbol of our shared civilization.
The secret to volcano coffee starts with the soil, almost too rich to fully comprehend its intricate ways of creation, renewal, and replenishment. Such an ecosystem echoes the complexity of the very best coffee only such soil is capable of producing.
True volcano coffee is by no means just a noteworthy hot beverage fitting into the routine; it is a powerful testament to the symbiosis between the provisions of nature and human craftsmanship.