Coffee is getting complicated. And I don’t mean understanding the difference between an American cappuccino (obnoxiously oversized like a bowl of fettuccine Alfredo from Cheesecake Factory) and the daintier original invented by the Italians (who are generally horrified by both our bastardization and willingness to drink one at any time of day.) But I digress.
Consider the term “green coffee.” Even the hue of standard commodity beans — the second most heavily traded commodity in the world after crude oil –- can be several shades removed. Referring to the color of beans before roasting, green coffee can range from dark raisin to dried chickpea, and the taste profiles, for those attuned to them, can also be wildly different.
This great variation in color derives from the processing and fermentation methods used in different regions, based on their weather conditions and resources. It should not come as a surprise to those with winemaking familiarity that this other carefully cultivated fruit also requires some application of chemistry.
What is processing? For all its negative connotations in the food world, processing freshly picked cherries references the necessary steps taken, which includes some degree of fermentation (yeasts and bacteria break down the sugars found in the mucilage to produce acids and fruit notes), to remove the three layers around the seed in order to prepare it for shipping, and later, roasting. Those layers are first, the outer fruit or pulp, second, the sticky mucilage covering the seed, and third, the parchment, or thin layer covering the seed that is named for its resemblance to parchment paper when dry.
As consumer palates have become more sophisticated, specialty coffee producers have begun using processing methods as a creative tool. Whether accentuating fruit notes, highlighting or softening acidity, and fattening or lifting the body, this creates product differentiation. Think about wine for a minute. Grapes left longer on the vine develop more sugar, thus more alcohol and a bigger body, and riper fruits. Grapes picked earlier have higher acidity, less alcohol, a leaner profile, and tarter fruits. While not an exact comparison, the point is to show that, from a producer standpoint, coffee processing decisions, along with terroir (e.g., a cool, coastal site in Sonoma v. a warm valley site in Napa) and tree variety (e.g., Pinot Noir v. Cabernet Sauvignon), influence the sensory properties of the final drink.
While experimentation continues, the three predominant processing methods you’ll find on the market are dry or natural (labor intensive), washed or wet (water-intensive), and a newer hybrid called honey or semi-dry.
Natural or Dry Processed
Natural is the original method — or rather, nature’s method — because in this case, the coffee cherries are picked and simply allowed to dry, often right up to the point at which they’re shipped as an export. This increases the risk of mold and the chance of over-fermenting into boozy flavors (sounds better than it tastes), and it takes weeks, but requires almost no water and allows the fruit to influence the taste. Some naturally processed coffees can remind you of blueberry pancakes in your cup (tastes as good as it sounds). It’s particularly common in Brazil, accounting for approximately 80% of that country’s production, and also in arid countries such as the birthplace of coffee, Ethiopia, where water is scarce. Some of the best Geisha’s from Panama are naturally processed.
Where to find dry processed coffee:
Blue Bottle’s -Yirgacheffe, Ethiopian
Washed or Wet Processed
For the more common washed process (at least outside of Brazil, the world’s largest coffee producer), the harvested cherries are placed into separation tanks filled with water, then run through a mechanical, often motorized, de-pulping machine, leaving the second layer, the sugary, viscous mucilage, to ferment for half day up to nearly a week. Fermenting much longer risks developing sour flavors. During this fermentation period, acids build up to eat away the sticky mucilage. After fermentation, the beans are washed again and immediately laid out in patios or drying beds. This controlled, but water-intensive, processing style leads to a cup with a bright, clean taste.
Where to find wet processed coffee:
Scotty D's Jamaican Coffee- 100% Blue Mountain Coffee
The Hybrid Method: Honey or Semi-dry Processed
Honey processing (the name is based on the sweet mucilage) borrows a little from both the natural and washed methods. The beans are dried while varying amounts of sticky mucilage still clings to them, like the natural process, but after the cherry pulp has been removed, similar to the washed process. After drying, the beans are de-pulped and moved to a drying station. There is less fermentation during honey processing, as it is confined to the relatively short time when the mucilage dries, resulting in a sweet cup with lower acidity. It’s a relatively recent practice, just over a decade old, that started in Costa Rica and spread throughout Central America. With variations in the amount of mucilage left on the seed, and hence, sweetness, additional categories of honey processed coffee were developed, and yellow, red, and black are used to describe these moderations.
What does all this mean for you, the consumer?
The originators of honey coffees helped spawn the idea of experimenting with fermentation and processing, once producers’ focus shifted from simply and expediently preparing seeds for roasting. It’s the dawn of an exciting time for specialty coffee. Timeworn techniques which greatly, but almost accidentally, determine how coffee tastes, are finally receiving adjustments to their formulas with the aim of producing a balanced, sweet, yet complex taste that deservedly reflects all the effort, time, and resources devoted to its creation. That’s the kind of complexity we should all welcome.