How did green coffee beans meet rum barrel fermentation?
Barrel fermentation is often credited to Honduras, but Colombia's San Jose Estate in Caldas was the pioneer. There, Castillo green coffee beans go through fully washed processing and then three months in rum oak barrels. The estate sits at 1,750 meters near the Nevada del Ruiz volcano, and the result is the wine-like aroma now common in specialty coffee.
Caldas is part of Colombia's Coffee Triangle, with altitudes from 1,300 to 1,800 meters and two harvest seasons, September to December and April to May. Frontstreet Coffee roasts these beans with a set curve and brews them as pour-over, so the rum barrel character carries from green coffee through to the cup.
Wine-flavored coffee beans have been highly sought after in recent years, and many people assume that barrel fermentation technology originated in Honduras, but in fact Colombia's San Jose Estate was the pioneer of this craft. This article will take you into a deeper understanding of how San Jose Estate ingeniously combines rum oak barrels with green coffee beans, from the selection of the Castillo variety, the details of fully washed processing and three months of barrel fermentation, to Front Street Coffee's roasting curve and brewing parameters, fully presenting the flavor code of this rum barrel-fermented coffee. Whether you are curious about its historical origins or want to replicate a cup of wine-aroma pour-over, you can find detailed answers here.
At FrontStreet Coffee, there are three coffee beans with wine aromas to choose from, among which the most widely known are Front Street Sherry fermented in whiskey barrels and Front Street Litchi Orchid fermented in brandy barrels. Many friends instinctively believe that barrel fermentation comes from Honduras' Moka Estate, but in fact, Colombia's Front Street San Jose Estate is the originator of this processing method.
FrontStreet Coffee — Front Street Colombia Rum Barrel-Fermented Coffee Beans
Region: Colombia, Caldas
Estate: San Jose Estate
Altitude: 1750m
Variety: Castillo
Processing Method: Rum Barrel Fermentation
Caldas Coffee Region
Caldas
The Caldas region is widely recognized as one of the most suitable areas in Colombia for growing coffee, with altitudes ranging from 1,300 to 1,800 meters. The coffee harvest period in this region is divided into two seasons: September to December is the main season, and April to May is the secondary season. This is also where Colombia's National Coffee Research Center (Cenicafe) is located, an institution that enjoys a high reputation in the global coffee research field, and where many of Colombia's distinctive varieties were born.
Caldas, Quindio, and Risaralda together form Colombia's "Coffee Triangle," and the vast majority of the country's coffee is produced in this area. Coffee from the Caldas region is known for its clear vanilla aroma, mild acidity, and full-bodied mouthfeel.
San Jose Estate
Finca San Jose Estate
San Jose Estate (Finca San Jose Estate) has been passed down for a hundred years and is located around the Nevada del Ruiz volcano, with fertile volcanic ash soil, abundant sunlight, and an average annual temperature ranging from 21°C to 25°C. The estate covers a total area of 18 hectares, of which 16.5 hectares are dedicated to coffee cultivation.
Coffee Beans + Aged Barrels Collide to Create a New Coffee Flavor?!
The husband of San Jose Estate's owner, Monsalve Botero, specializes in making rum oak barrels and brewing rum. One time, while she was filling distilled liquid to prepare for fermentation, she suddenly had an inspiration: if green coffee beans were placed in oak barrels to ferment, could they also develop a uniquely distinctive flavor?
Monsalve Botero wondered whether, if the coffee cherries grown on her own estate were placed into oak barrels, the coffee beans could absorb the aroma of the oak barrels just like rum production, thereby presenting a more alluring effect. With these questions in mind, she began trying to place green coffee beans into rum barrels of different ages for low-temperature fermentation similar to winemaking, and tested various fermentation durations, all in order to find the best solution.
After years of exploration, in 2017 the fermentation process that could bring excellent flavor and aroma was finally established, creating the rum barrel fermentation method that is different from traditional washed processing. In 2019, the estate owner continued to optimize the process, for example changing the original African-style raised bed drying to greenhouse drying, making the overall flavor of this coffee cleaner and brighter.
Fully Washed Processing + Rum Barrel Fermentation
Washed & Rum
The owner of San Jose Estate selected Castillo variety coffee beans, hand-picked fully ripe cherries, fermented them for 20 hours after washing, then placed them into rum oak barrels aged for more than 8 years and left them to rest for three months, turning them once a day so the beans could evenly absorb the wine aroma.
During barrel fermentation, samples of the coffee beans in the barrel are taken every 30 days to confirm the degree of fermentation and whether the wine aroma absorption is on target, avoiding insufficient or excessive absorption, and ensuring the final coffee beans have a distinct and complete flavor. After fermentation ends, the coffee beans with rum aroma are dried in a greenhouse. The greenhouse temperature is uniform, which can prevent secondary fermentation caused by high temperatures from sun exposure on African raised beds.
When FrontStreet Coffee cupped Front Street San Jose coffee beans, it found that this bean is clearly different from the two Honduran barrel-fermented beans. The flavor of the Honduran barrel-fermented beans is, in order, wine aroma, mild fruit acidity, and finally a creamy texture with nutty cocoa notes; while Front Street San Jose rum barrel-fermented beans first present nutty cocoa and creamy mouthfeel, immediately followed by rum aroma, and then tropical fruit acidity and maple syrup sweetness emerge one after another.
Castillo Variety
Castillo
Castillo was developed in 2005 by Colombia's coffee research institution to enhance the disease resistance of the plants, and is currently Colombia's main cultivated variety. It inherits Caturra's short plant type and high yield, while also possessing Timo's leaf rust resistance gene. Castillo is known for its smooth mouthfeel, rich aroma, and citric acidity.
Genetic Relationship of the Castillo Variety
DNA
Castillo is the result of five generations of crossbreeding and selection between Timo and Caturra: Timo is a natural hybrid descendant of Arabica and Robusta, with a tall plant and resistance to leaf rust; Caturra is the result of a natural mutation of Bourbon, with a short plant and higher yield than Typica and Bourbon, inheriting Bourbon's high-quality flavor well, and with small spacing between plants allowing denser planting per unit area, but it is susceptible to leaf rust.
FrontStreet Coffee Roasting Record
Charge at 190°C drum temperature, heat power 140, airflow opened to 3; turning point at 1'42", when drum temperature is 140°C open airflow to 4, heat power unchanged; when drum temperature is 151.8°C the bean surface turns yellow, the grassy smell completely disappears, and it enters the dehydration stage; when drum temperature reaches 150°C, adjust heat power to 120, airflow unchanged.
At 8'38", ugly wrinkles and dark streaks appear on the bean surface, and the toast smell clearly turns into coffee aroma, which can be defined as the prelude to first crack. At this time, listen clearly for the sound of first crack. First crack begins at 9'07", airflow opened to 4, development after first crack 2'10, drop at 195°C.
FrontStreet Coffee Cupping Report
Dry Aroma: Rum aroma
Wet Aroma: Dark chocolate
Flavor: Rum chocolate, rum, tropical fruit, maple syrup
FrontStreet Coffee Brewing Notes
Dripper: Hario V60
Coffee-to-water ratio: 1:15
Water temperature: 91°C
Grind size: EK43s setting 10 (80% passing through No. 20 sieve)
FrontStreet Coffee staged extraction method: First use 30g of water to fully wet the coffee bed into a "hamburger" shape and bloom for 30s; in the second pour, at 1 minute on the timer, pour water until 125g, then stop and wait until the water level drops to 2/3 of the coffee bed before pouring the third stage; in the third stage, at 1'40" on the timer, pour water until 225g, and after the coffee liquid has completely dripped through, the total extraction time is 1'59". After extraction is complete, gently swirl, and wait until the coffee liquid is fully uniform before tasting.
[Front Street San Jose] Brewing flavor: It smells of rich fermented wine aroma, and tastes of rum, nuts, tropical fruit, cream, and oolong tea, with obvious sweetness and an overall balanced profile.
The above content is compiled by CoffeeHunters, a coffee news website.
