Coffee sourcing involves carefully considering everything from growing and harvesting practices to processing and milling. We believe that this quality-driven approach is consistent with a business model that consistently prioritizes social and environmental sustainability.
GROWING AND HARVESTING
Coffee is grown in the equatorial regions of the Americas, South and Southeast Asia, and Africa. Each of these three major coffee-growing regions is known for its own general cup profile, or combination of flavors and aromas found in a brewed cup of coffee. Each coffee-producing region has a unique set of growing, harvesting, and milling practices, which also impact the final quality of the bean.
Coffees grown at higher elevations tend to be higher quality. At higher elevations, the temperature difference between night and day is more extreme, forcing coffee cherries to ripen more slowly, developing sugars that yield complexity in the cup. Coffee grading systems are often structured according to elevation; in Guatemala, for example, Strictly Hard Bean (SHB) coffees are grown at or above 4,500 feet above sea level.
Harvesting practices also dramatically impact the coffee's final quality. Specialty coffee producers are careful to pick only perfectly ripe cherries, bypassing all fruit that does not match the perfectly desired shade of red. Under-ripe and over-ripe cherries introduce inconsistencies into the fermentation process, and can cause undesirable flavors in the cup.
Processing refers to the way that fresh coffee cherries are converted into green coffee beans ready for roasting. Depending on the country and region, certain processing steps may take place either on the farm or at a central mill.
Processing should begin within 24 hours of the coffee being picked from the tree. If processing is delayed, the fruit will begin to spoil, ruining the coffee seeds contained within the cherry. Consistent processing methods and clean, well-maintained processing equipment are essential to preserving coffee quality. Coffee can be processed several different ways:
- In the washed process (sometimes called the wet process), coffee cherries are first de-pulped to remove the outermost layer of fruit. They are then soaked in a fermentation tank for up to 36 hours. The fermentation process breaks down the sugars in the sticky mucilage. Cherries are then rinsed in fresh water to wash away the mucilage, density-sorted, and laid out to dry.
- In the dry natural process, cherries are left out to dry with the fruit layer intact. After drying, this fruit is mechanically removed to reveal the green coffee seed inside.
- In the semi-washed process (sometimes called wet-hulling), the cherries are first passed through a mechanical de-pulping machine, but then the coffee is left out to dry with the mucilage still on the bean.
Green coffee, now known as parchment, can be dried in mechanical driers or laid out to dry under the sun, on patios or on raised beds. A steady, consistent drying process is necessary to help the coffee beans develop better structure, which improves the coffee's shelf life. Once the coffee's moisture content has decreased to a specified target (usually around 11 or 12 percent), the coffee is ready for milling.
Milling is one of the most crucial steps in preserving the final quality of the coffee. Specialty coffee exporters utilize a meticulous milling process to remove all the lower quality beans that are not fit for export.
First, the parchment coffee must be run through a hulling machine, which removes the layer of parchment from the seed. The green coffee then moves through a screener to separate the coffee by bean size. Further sorting occurs with the winnower, a slanted table that vibrates, shaking the coffee and separating lower density coffee from higher density coffee. The last step is a final round of hand-sorting, where workers at the mill pore over the coffee looking for discolored, damaged, or otherwise defective beans.