Costa Rican Rock Manor Coffee Anaerobic Fermentation

FrontStreet Coffee - Costa Rica Giant Stone Estate Anaerobic Fermentation

Region: Brunca

Estate: Giant Stone Estate

Altitude: 1,600 m

Processing Method: Anaerobic Fermentation

Varieties: Caturra, Catuai

Grade: SHB

Costa Rica began cultivating coffee two hundred years ago, with the first plantings on the slopes of the Poas and Barva volcanoes, what we now call the Central Valley.

Costa Rica has eight main producing regions today: West Valley, Central Valley, Tarrazu, Tres Rios, Orosi, Brunca, Turrialba, and Guanacaste.

Brunca is a region in southern Costa Rica made up of states such as Coto Brus, Buenos Aires, and Pérez Zeledón. Coffee cultivation began in Perez Zeledón at the end of the 19th century, and Brunca is one of Costa Rica's six socioeconomic regions. It holds a variety of landscapes from the coast to inland mountains, bordering Panama to the east and the Pacific Ocean to the south and west.

Giant Stone Estate sits in Brunca, in southern Costa Rica. Because its topography connects to Panama, it has diverse microclimates. Near the estate, stone carvings made by indigenous people between 200 BC and 1500 AD have been unearthed, known as the mysterious stone spheres, which is where the name "Giant Stone" comes from.

Anaerobic Fermentation

As a relatively new coffee processing method, anaerobic fermentation goes by several names. Many call it "anaerobic fermentation," while others refer to it as "carbon dioxide maceration." Simply put, it is fermentation in a low-oxygen or oxygen-free environment, typically using a pressure-resistant stainless steel tank that allows control of temperature, time, pH, and other data needed to steer the fermentation.

The process originates from red wine production, where carbon dioxide is injected into a sealed container to expel oxygen. In an oxygen-free environment, the breakdown of sugars in the coffee mucilage slows, pH drops more gradually, and fermentation time extends. This develops better sweetness and more balanced flavors, ultimately producing beans with a distinctive character.

During fermentation, pH is an important reference. Temperature and pH changes must be strictly controlled. When the sugars in the mucilage are just fully consumed, the container should be opened immediately to stop fermentation, and the beans dried at once in sunlight to avoid over-fermentation.

Fermenting in a sealed environment reduces the uncontrollable factors that come from outside. A longer fermentation in an oxygen-free environment can increase rounded flavors while avoiding uncomfortable astringency and acetic acid.

Varieties

Caturra is a variety of Bourbon, discovered in Brazil in 1937. Its productivity and disease resistance are both better than Bourbon's, and the plant is shorter, which makes harvesting convenient. It adapts easily, needs no shade trees, and suits cultivation from altitudes as low as 700 meters up to 1,700 meters. Its altitude adaptability is strong, but higher altitudes yield better flavor with relatively lower productivity.

Catuai is also an Arabica hybrid, a cross between Mundo Novo and Caturra. It resists natural disasters better, particularly wind and rain. It inherits Caturra's short stature while addressing the shortcomings of Mundo Novo.

FrontStreet Coffee Recommendation

If the experimental, fruit-forward style of anaerobic fermentation appeals to you, the world of Panamanian Geisha is a natural next step. FrontStreet Boquete Gesha is an estate-level introduction to the variety, grown at 1,600 meters in fertile volcanic-ash soil. Brewed as pour-over or cold brew, it shows the jasmine, green tea, honey, citrus, and orange that define Geisha at its best.

FrontStreet Butterfly is another way into this profile. Made from Geisha, Caturra, and Catuai planted in Boquete's Baru Volcano area, it benefits from abundant rainfall, wide day-night temperature swings, and a distinct volcanic soil. Expect a full body, citrus acidity, and clear Geisha jasmine aroma, and it is equally happy as pour-over or cold brew.

For the top of the category, FrontStreet Emerald Estate Red Label Gesha is picked from a single plot above 1,700 meters and cups above 91 points, with a refined orange-blossom and honeyed character that shows how much nuance careful processing can add.