Alejo Kahle Castro: Heritage, Innovation & The Future of Costa Rican Coffee

High in the mountains of Costa Rica, where volcanic soils meet cool night air, the story of Alejo Kahle Castro continues a legacy that began more than two centuries ago. As the fifth‑generation producer behind Hacienda La Unión, Hacienda Colima and the Volcán Azul micro‑mill, Alejo blends tradition, science and environmental stewardship to create some of the most expressive coffees in Central America.

This is the story of a family whose pursuit of excellence shaped Costa Rican coffee — and the producer who is carrying that vision into the future.

A Legacy Born in the 19th Century

At the beginning of the 19th century, when coffee production in the Americas was still in its infancy, two pioneers unknowingly set the foundation for a dynasty. Alejo C. Jiménez in Costa Rica and Wilhelm Kahle in southern Mexico shared the same dream:

“To produce the best coffee in the world.”

Their goal was to satisfy Europe’s emerging gourmet market — a bold ambition that would define generations of farmers to come.

Today, their descendants continue to farm with the same ideals of excellence, quality and respect for the land. Hacienda La Unión has been in the Castro‑Kahle family since the 1840s, and under Alejo Kahle Castro’s leadership, the farms have earned multiple Cup of Excellence placements, including 2nd place in 2017 and multiple awards in 2020 and 2021.

Farming Above 1400 MASL: Where Quality Begins

The family’s farms sit on highly fertile volcanic soil above 1400 masl, across three regions of Costa Rica. These altitudes — combined with cool nights and slow cherry maturation — create ideal conditions for developing complex, structured flavour.

But Alejo is quick to remind people that great coffee begins long before harvest.

Pre‑Harvest: The Most Important Work

Alejo explains:

“This is the part of the process that catches less attention, but it's probably the most important. It takes constant hard work for years, and stopping even briefly can spoil everything.”

Pre‑harvest work includes:

• Planting the best varietals suited to the microclimate
• Managing soil health so trees receive balanced nutrients
• Protecting plantations from disease
• Ensuring long‑term sustainability for future generations

This year‑round commitment ensures that every cherry has the potential to become exceptional coffee.

Harvest: Picking at Peak Sweetness

When harvest arrives, precision becomes everything.

Alejo’s team picks cherries only at optimum ripeness, guided by brix measurements — the sugar content of the mucilage. On his farms, cherries typically reach 22 brix, and some varietals push as high as 28–30 brix.

Higher brix = higher sweetness = deeper, more complex flavour.

This scientific approach ensures that every lot begins with maximum potential before processing even begins.

Volcán Azul Micro‑Mill: Where Innovation Meets Tradition

All cherries from Hacienda La Unión are processed at the Volcán Azul micro‑mill — a place where heritage techniques meet modern experimentation.

The Wet Mill Process

The journey begins with measuring incoming cherries by volume:

• A 200‑litre box is used
• Two boxes = 1 fanega (400 litres)
• One fanega yields ~46 kg of green coffee

Next, floaters are removed — these are underripe, over‑dried or defective cherries. The coffee is then cleaned of branches, leaves, dirt and any foreign matter from the field.

Only then does the team decide which process each lot will receive.

The Importance of Slow Drying

Alejo emphasises:

“It’s fundamental to slow dry our coffee to preserve quality. The more mucilage, pulp and time, the more fermentation we develop.”

This careful drying — whether on patios or raised beds — is essential for building the expressive, fruit‑forward profiles Alejo is known for.

Environmental Stewardship: A Family Commitment

The Castro‑Kahle family’s dedication extends beyond coffee. They have acquired large areas of natural rainforest to protect and conserve biodiversity.

These actions — not just words — reflect their commitment to:

• Reducing air contamination
• Protecting natural resources
• Mitigating global warming
• Preserving ecosystems for future generations

It’s a philosophy rooted in responsibility, not marketing.

A Producer Shaping the Future of Costa Rican Coffee

Under Alejo’s leadership, Volcán Azul has become one of Costa Rica’s most respected mills, consistently placing in the Cup of Excellence and producing coffees sought after by roasters worldwide.

His work represents the perfect balance of:

• Heritage farming
• Scientific precision
• Environmental responsibility
• Fearless innovation

Alejo Kahle Castro is not just a coffee farmer — he is a steward of history, a champion of quality, and a visionary shaping the future of Costa Rican specialty coffee.