What Does Semi-Dry Volcano Processing Mean? How to Differentiate Between Honey Processed and Semi-Dry Coffee Beans?

Understanding Coffee Processing Methods

We often hear the words natural, honey and washed in cafes - these refer to the various ways raw coffee beans are processed.

When coffee is still growing on the tree with its skin and pulp, it is called a "coffee cherry." The coffee bean is really just the seed at the center. The process of removing the outer skin, pulp and mucilage after harvest is called "green bean processing."

Fermentation is what causes the beans to undergo chemical changes and develop more flavors.

Coffee cherries ferment while they dry, and it is this fermentation that develops more flavors in the bean. Processing methods have evolved continuously. Producers keep experimenting with different fermentation techniques - controlling the source of fermenting bacteria (anaerobic fermentation), adding ingredients to feed the strains, and varying sugar sources and concentrations. By using fruit pulp, cola, alcohol and other substances, they can alter the fermentation bacteria and create different flavors. Adding cola, for example, is said to produce cardamom and cinnamon notes. Adjusting flavor from the processing stage is an emerging technique, and many coffee professionals are still researching the details.

Natural Process

Coffee cherries are poured into large water tanks, where buoyancy sorts out inferior beans. The good fruit is then scooped out and spread evenly to dry in the sun. Finally, a hulling machine removes the fruit skin and mucilage.

Flavor Profile

Because the whole fruit ferments together, the fermentation notes are most pronounced in the cup.

Washed Process

As with the natural method, soaking removes floating inferior beans. Then machines remove the fruit skin and pulp, and the beans are placed in water tanks. Fermentation dissolves the mucilage, and finally the beans are machine-dried.

Flavor Profile

Compared with natural process beans, the flavor is cleaner and more refreshing.

Honey Process

The honey process is a compromise between the natural and washed methods.

What is commonly called "semi-natural" or "semi-washed" can all be considered types of honey processing. The honey process sits between the two: it removes the fruit skin before sun-drying but retains the pulp and mucilage layers. After drying, machines remove the sticky layer and silver skin.

Flavor Profile

The mucilage feels sticky like honey, and it is this that gives honey-processed coffee its higher sweetness.

Innovative Processing Methods

Soaking green beans in oak barrels allows them to absorb the barrel's flavors.

Various green bean processing methods exist around the world. Here we introduce some newly added "flavor-infused" creative methods.

Washed Oak Barrel Fermentation Process

The initial steps are similar to washed processing, but instead of placing the beans in water tanks they are soaked in oak barrels to absorb the barrel's flavor. When a production is scaled up to mass production, wood chips or alcohol are used in place of the oak barrels.

Flavor Profile

Features candied fruit, brandy and toffee notes.

Mango Pulp Infusion Fermentation Process

At the stage when green beans would ordinarily go into water tanks, fruit pulp is added instead to influence the fermentation flavors. This can add floral, passion fruit, lychee and other tropical fruit notes to the green beans. Different fruits, of course, create different variations.

Flavor Profile

Features tropical fruit flavors.

FrontStreet Coffee Recommendation

Honey processing is the story of how much mucilage a producer chooses to leave on the bean, and FrontStreet Coffee's lineup shows the full range. FrontStreet Brazil Cerrado is a classic Brazilian half-sun - a forerunner of honey processing - with clear cream, peanut, nut and chocolate flavors. The method caught Costa Rica's attention, and Costa Rica improved on it by varying how much mucilage is retained and how long the coffee dries, splitting the style into black, red, yellow and white honey.

FrontStreet Costa Rica Blackberry is the deepest expression of that idea. Its black honey process removes almost no mucilage and dries for at least two weeks, using shade covers to keep the sun from drying the fruit too fast, and the beans are turned at intervals so they do not over-ferment. Roasted medium-light, FrontStreet Blackberry smells of fresh flowers when ground and drinks with grape, berry and ripe blackberry flavors.

At the other end of the spectrum, FrontStreet Strawberry Candy is a blend of Panama Geisha and Costa Rican coffee. The Costa Rican component uses a raisin honey process with 100% of the mucilage retained and zero water; the cherries are floated to remove immature and overripe fruit, dried on raised beds for at least three days, then depulped and dried further while being turned constantly for evenness. The result keeps the Geisha's floral-tea character while adding grape and dried blueberry, soft fruit acidity and an almond finish. FrontStreet Mozart uses the same raisin honey approach and, whether brewed as pour-over, cold brew or in a Moka pot, delivers distinctive osmanthus, pineapple and raisin aromas.