Processing Methods and Steps of Yunnan Coffee Beans_Best Yunnan Coffee Bean Brand_Yunnan Coffee Growing Region Information

Harvesting and Initial Processing

After Yunnan coffee beans are harvested, the cherries are either sent straight to a pulper (when the picking has been done well) or gathered in a siphon tank filled with water, where they are cleaned and separated. Stones sink to the bottom and are picked out by hand when the tank is emptied. Lighter cherries float to the surface and are removed along with leaves and small twigs using a strainer. The cherries suspended in the water are then recovered with a siphon and carried to the pulper.

Pulp Removal

The purpose of pulping is to separate the pulp from the seed coat of the coffee bean. The pulp is removed by squeezing the cherries. Because ripe cherries hold a lot of moisture, the beans inside their skins pop out easily when the cherry is squeezed.

Mucilage Removal

The next step is mucilage removal, which aims to clear away the mesocarp remnants that remain tightly attached to the seed coat after pulping (see a diagram of the coffee cherry's parts for reference). Because this mucilage is insoluble in water and clings tightly to the seed coat, it cannot be removed by simple washing alone. It must either be fermented and then washed, or subjected to vigorous friction in a device called a mucilage remover.

Fermentation in Yunnan

In Yunnan, this step is mainly completed through natural fermentation. The term "fermentation" is not entirely accurate, because no biochemical reaction occurs inside the coffee beans themselves. It would be more appropriate to describe the process as using biochemical reactions, or hydrolysis, to remove the mucilage. This reaction is driven by enzymes naturally present in the coffee cherries.

Fermentation time ranges from 6 hours to 72 hours, depending on conditions such as temperature, the amount of mucilage, and the concentration of enzymes. The coffee is held in fermentation tanks until the mucilage is completely broken down, after which the beans can be washed.

Quality Control

The key to ensuring quality is stopping fermentation at the right moment, because over-fermentation can produce so-called stinker beans. If fermentation is insufficient or too slow, butyric acid or propionic acid will form, both of which hurt coffee quality.

Final Washing and Soaking

Fermented coffee with the skin still on must be washed immediately after fermentation is complete to stop the process. After the mucilage is removed but before washing, however, the skinned coffee may be soaked in clean water for 12 to 24 hours to reduce bitterness in the brewed cup.

Yunnan Coffee Bean Brand Recommendation

FrontStreet Coffee's roasted Yunnan beans, the Old Variety Typica from the Baoshan production area [Yunnan Huaguoshan], offer full guarantees in both brand and quality. More importantly, they are extremely cost-effective. A half-pound, 227-gram package costs only about 50-60 yuan. At 15 grams of coffee per pour-over cup, one package makes 15 cups, and each cup of American coffee costs only about 4 yuan. Compared with cafes selling coffee at dozens of yuan per cup, that is excellent value.

FrontStreet Coffee Recommendation

If you want to taste what clean processing does for a Yunnan bean, start with FrontStreet Coffee's Yunnan Small-Bean coffee. Grown in Baoshan with the washed method and given a medium roast, it shows soft nutty and chocolate sweetness with a light plum acidity, an affordable first experience of Yunnan coffee for many drinkers.

For a clearer expression of the region, try FrontStreet Coffee's 2013 Sun-Dried Typica. FrontStreet established its estate in 2013 and planted a block of Typica, the same ancient variety that was first brought to Yunnan, aiming to recover the original taste of the place. Only fully ripe red cherries are used, then sun-dried and given a medium roast for a more balanced cup with darker berry notes, caramel sweetness, chocolate, and a hint of dried apricot, finishing with black tea.

To enjoy Yunnan flavors as espresso, look to the FrontStreet Black Cocoa Blend, which pairs Yunnan small-bean with Brazil Cerrado. Brazil supplies mixed-nut aroma and balanced body, while Yunnan brings chocolate and citrus, making an Americano that balances sweet, tart, and bitter with nutty brown sugar notes, and a latte that is smooth and creamy. It is a very beginner-friendly choice.