The Cerro San Luis Micromill is a family operation run by siblings Alexander and Magali in the West Valley of Costa Rica. Coffee runs deep in their family life and, as Alexander and Magali explain in a recent Cafe Imports mini-documentary, they say “coffee was practically born with us”.
Over the years, the San Luis Micromill has focused on reinvesting in coffee knowledge, learning all they can about processing, cupping, brewing, and roasting. They also started growing different varieties. About 4 years ago, they replaced their older stock with 10 or more different types of coffee, including Caturra, Red and Orange Bourbon, SL-28, Catuai, Villa Sarchi, and Maragogype.
This investment returned high yields, and scores of their coffee improved as well as opening the door to new markets for buyers looking for innovative and different coffees. Alexander and Magali’s love and commitment to coffee is evident not only in their hard work and agricultural practices but in the quality of the green coffee and cup as well.
A Region as Complex as the Coffee Itself
Costa Rica is a relatively small country and only makes up less than 1% of global coffee production. However, its growing regions are diverse and complex much like the coffee it exports. This particular offering comes from the West Valley, which is home to many Cup of Excellence growers as well as the Bourbon mutation Villa Sarchi, a varietal that was discovered in this region. The micromills in the West Valley are at a high elevation and experience cooler weather than the rest of the country, resulting in high sugar production within the cherries and high-quality offerings.
A Well-Traveled Varietal
The SL-28 is one of the most well-known of the African varieties. A descendant of the Bourbon family, it was originally discovered in Tanzania. It has been selectively bred for its tolerance to drought as well as its very low maintenance care needs and was developed by Scott Agricultural Laboratories (now known as National Agricultural Laboratories) in Kenya in the 1930’s. There are even SL-28 trees in many parts of Kenya that are 60-80 years old and still productive.
Like the history of many coffee varietals, it’s hard to pin down when or how the SL-28 arrived in Costa Rica. While we’ve seen SL-28 offerings coming out of Costa Rica for at least 10 years now, it’s possible that it could’ve been brought over unofficially earlier than that. There is a lot of speculation about how it got here—it could have even leaked out of some academic germplasm banks or brought over across the borders at some point. However, there was never an official introduction, and Costa Rica has never done DNA testing to even know if it is the real SL-28. While it’s fairly safe to say that this is a SL-28, it’s also very possible that the SL-28 in Costa Rica has mutated to adapt to climate and conditions and is different from the SL-28 in Kenya.
Innovative Processing
This coffee undergoes an Anaerobic Honey process after harvest. All green coffees go through a fermentation process before drying, and this coffee is fermented anaerobically, as opposed to open-air fermentation. While the term anaerobic means “without air” most coffee that is being fermented anaerobically is in a low-oxygen environment, as fermentation is near impossible without oxygen to move the process along. For this offering, the coffee cherries are fermented overnight in plastic bags before being taken to the mill to be depulped the following day.
This method is slightly different from other honey processed coffees where usually the cherries are depulped fairly quickly after harvest. After being depulped, the coffee is moved to stainless steel tanks where the anaerobic process begins. The coffee is left to ferment for 6-48 hours depending on the desired cup quality and brix readings.
After the fermentation stage, the coffee is washed to avoid stains on the parchment. The coffee is dried on raised beds in a greenhouse, and the temperature is controlled to not rise about 45°C. Coffee is moved constantly until it reaches a range of 10-11% of humidity. This can take 3-4 days depending on the weather.
In our Roastery
Special lots from Costa Rica have an important place in our roastery. Most commonly, we are looking for honey processed lots. Recently, we were shopping for a unique coffee for an upcoming trade show when we saw this highly regarded SL-28 varietal combined with the buzzy anaerobic honey processing. We were intrigued.
When we think of SL-28 coffees from Kenya, we think of stone fruit, with high and lively acidity. Seeing this variety pop up on an entirely different continent with different terroir, we knew we would experience a unique and interesting cup.
This coffee retains the acidity we know and love from the SL-28 varietal while adding the unique sweetness that Costa Rica honey processed coffees deliver.
This coffee is very limited in supply, and may only last until the end of Summer on our toll menu. We focus on a well-developed light roast for this coffee to highlight what makes this lot special. Check it out on our greens page while it lasts, where you can view our detailed cupping notes and look at our preferred roast profile on RoastPATH.
References
Cafe Imports. Echoes of Coffee: Narratives from Costa Rican Producers. June 18th, 2024.
https://www.cafeimports.com/north-america/blog/2024/06/18/echoes-of-coffee-narratives-from-costa-rican-producers/ Accessed June 19th 2024
Cafe Imports. Fermentation. Dr. Taya Brown. January 30, 2023 https://www.cafeimports.com/north-america/fermentation Accessed June 19th 2024
World Coffee Research. Varieties Catalog. WCR, 2024
