The Castillo coffee variety is controversial. On the one hand, it’s rust-resistant. On the other, coffee professionals are wary of the fact that its parents include Robusta-Arabica hybrids.

But what actually does Castillo offer for coffee producers? Can you get high-quality single origin Castillos? And, as rust-resistant varieties make the news for decreasing resistance, what does the future look like for this variety?

I had the opportunity to speak to two experts from Colombia’s National Coffee Research Centre, Cenicafé: Olga Inés Puerta Quintero, Research Scientist, and Hernando Cortina, Coffee Breeding Scientist. Here’s what I learned.

Spanish Version: Variedades de Café: Desmintiendo Mitos Alrededor de la Variedad Castillo

Castillo variety in Valle del Cauca, Colombia. Credit: Finca La Julia

Leaf Rust Resistant Varieties

Coffee leaf rust, or la roya in Spanish, is one of the biggest threats to a farmer’s crops. The disease affects the leaves of coffee plants, appearing in the form of yellow-orange spots. Since the leaves are where photosynthesis occurs, when leaf rust hits, plants are less able to produce energy. In the worst of cases, the leaves fall off the tree, which is then unable to produce any coffee cherries.

A coffee leaf rust epidemic hit Central America in 2012, and the region is still recovering from the impact today. Then, this Spring, news emerged that Lempira, a variety previously considered rust resistant, has been infected with rust in Honduras.

These developments make the discussion around rust-resistant coffee varieties even more poignant – but it’s not a new conversation. Coffee leaf rust has been an issue for over a century (although it took until 1990 for it to be confirmed in all major coffee-producing countries). Research centres around the world have been working to produce rust-resistant coffee plants for decades.

The challenge has been creating a rust-resistant variety with a good cup profile.

Castillo growing on Finca La Palma in Vereda Caloto, Paicol, Huila, Colombia. Credit: Coffeeland

Creating Castillo

Café de Colombia’s research centre Cenicafé is dedicated to studying and improving all aspects related to coffee farming. In 1968, it began a genetic improvement programme to create rust-resistant varieties.

The centre first looked to Caturra and the Timor Hybrid, Hernando tells me. Many rust-resistant varieties have been made that way, and are labelled Catimors. Caturra is small and compact, which allows producers to grow more plants in the same area. The Timor Hybrid, on the other hand, is an Arabica-Robusta cross from East Timor that offers rust-resistance.

The first experiments gave place to the Colombia variety. It was released in 1982, one year before leaf rust reached the country for the first time, Hernando tells me.

But he explains that Cenicafé wanted to improve the variety even further. The goal was greater productivity, greater resistance, bigger beans, and greater quality – similar to that of Caturra. On top of this, given the long life of coffee plants, hardiness was important.

Many more trials later, the team finally succeeded. Cenicafé had created five generations of the variety that would be called Castillo, and – after 23 years of research and development – it was released for production in 2005.

It’s common for rust-resistant varieties to lose resistance over time; equally, no coffee variety is resistant to every race of leaf rust. (Fortunately, however, most regions do not suffer from every race.)

Yet today, after 12 years, Castillo is still resistant – both to leaf rust and coffee berry disease. “We hope to keep it [resistant] for 15 more years,” Hernando tells me, “which will give us time to create new varieties.”

45% of Colombia’s coffee is Castillo, according to Cenicafé. Credit: Angie Molina Ospina

Castillo in Detail

Castillo is known for its smoothness, aroma, and citric acidity. Gloria tells me that through blind testing and other sensory evaluations, Café de Colombia discovered it can have similar qualities to Typica, Caturra, and Bourbon.

Cenicafé succeeded in giving Castillo the short stature of Caturra, along with relatively high yields, making it a good choice for producers. Not all Castillo is the same, however: Cenicafé created six different forms of Castillo, designed to meet the climate conditions of six different regions.

This diversity will help Castillo to remain rust-resistant. “We need to keep different lines in anticipation and preparation for the evolution of the disease,” Hernando says. He also tells me that the more homogenous the coffee crops, the bigger the risk of the disease spreading.

You’ll find Castillo El Rosario in Antioquia Department, Castillo Naranjal in Caldas Department, Castillo Paraguaicito in Quindío Department, Castillo La Trinidad in Tolima Department, and Castillo Pueblo Bello in Cesar Department, and Castillo Santa Bárbara in Cundinamarca Department.

Castillo in Valle del Cauca, Colombia. Credit: Finca La Julia

Castillo vs Caturra: Is One Better?

Hernando and Gloria know that some specialty coffee buyers consider Castillo to be of a lower quality than other varieties. Yet they tell me that it has contributed to the sustainability of the Colombian coffee industry, since it requires less fungicides. These can both damage the environment and increase the cost of production for farmers.

And there is also some evidence that Castillo can have the potential for high-quality specialty-grade coffees.

In 2014, the International Center for Tropical Agriculture (CIAT) in Colombia, World Coffee Research (WCR), the Sensory Analysis Center at Kansas State University (KSU), and several cuppers collaborated to form the Colombia Sensory Trial. During 2014 and 2015, they undertook a comparative sensory analysis of Castillo and Caturra. The coffee analysed was all cultivated on the same farm, and processed using the same methods.

The results? While the flavour profiles varied greatly, the two varieties had similar cup scores. Some Castillo samples were cupped at 90+ points.

What’s more, the recommendation made to producers was that the variety may be less important than the environment and farm management. Soil fertility, shade management, harvesting and processing practices – these are the kinds of things things that correlated with cup scores, not the variety.

Gloria explains that ensuring quality in the final cup is a comprehensive process. “It does not only depend on the variety, although that will give certain sensory qualities, but also on the processing method, drying, picking, and farm altitude.”

Growing conditions can be more important than coffee variety. Credit: Coffeeland

SEE ALSO: Bourbon vs Caturra: What’s a Variety & Why Should I Care?

The Importance of Preemptive Action

Preemptive action meant Colombia already had a leaf rust resistant variety before the disease struck in the 80s. And Cenicafé believes that this is crucial.

Coffee berry disease is mainly found in Africa, and has not yet appeared in Colombia. But Hernando says it was important for Cenicafé to ensure Castillo was resistant to it.

There are many more challenges facing coffee growers. Temperature increases can stunt Arabica coffee, reducing its yield, and also make it more sensitive to coffee pests.

Hernando mentions the importance of being prepared for damages caused by both biotic (the living things in an ecosystem, like insects) and abiotic (the nonliving parts of an ecosystem: sunlight, temperature, atmospheric gases, water and soil) factors. Droughts, soil acidity, pests – they can all limit coffee production.

“We are currently working on the development of new varieties to deal with these issues,” he says.

What’s more, Cenicafé knows that leaf rust will always be a threat, and can always evolve. “A preventive way of dealing with it is to incorporate new genes that could create new resistance in the varieties,” Hernando continues.

And until those new varieties are created, Castillo offers producers and buyers rust resistance, good yields, and the potential for high cup scores.

All interviews conducted in Spanish and then translated into English by the author.

Please note: Café de Colombia is a sponsor of Perfect Daily Grind and was consulted in the creation of this article. They have received a courtesy copy of the article prior to publication but have exerted no editorial control over the final copy.  

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