On the vast majority of coffee farms, no matter where they are in the world, coffee farmers use variations of the same 3 processes to transform fresh coffee cherries into dry coffee beans ready for sale: the natural, honey and washed processes. Winemakers and beer brewers, on the other hand, are constantly experimenting and pushing the boundaries of their craft- resulting in a steady stream of new and exciting flavors in those beverages. Coffee famously has more flavor compounds than wine- so why aren’t more coffee producers experimenting with them?
We wondered whether there were some inherent properties of coffee cherries that would limit the range of processing options- or whether uninventive coffee processing could be better explained through cultural convention, lack of resources, or simple historic momentum. We decided to find out.
In the fall of 2013, Luisa and I spent a month at Finca Manantiales del Frontino, a 170 hectare coffee farm that grows specialty varieties with a focus on quality in Colombia’s Valle de Cauca. We were there primarily to explore three questions:
Manantiales was a beautiful spot, and everyone we met there was incredibly welcoming, supportive and friendly. We owe a whole-hearted thank-you to the entire team. Please pay them a visit if you’re ever in their neighborhood and try their amazing coffee.
Manantiales set us up with a small group of their best pickers to supply us with the highest quality, uniformly-ripe cherries. We planned experiments using 5kg lots of geisha and red bourbon cherries. Over the course of several weeks, we completed 10 different process experiments with geisha, and another 9 with bourbon. We divided the experiments into two intervention periods: maceration, or any processing while the coffee was still wet, and drying.
The processes were:
Geisha
1. Refrigerated macerated mashed cherriesBourbon
A. Whole cherries frozenIa. Shorter cacao fermentation
In general, we were using what tools we could find to manipulate time, temperature and biotic variables. (We also attempted to manipulate pressure with a stainless steel whip cream maker, but unfortunately the one we bought in Bogotá (and didn’t test until we were at the finca) turned out not to hold pressure. More on pressure experiments soon…)
When we were finished and had all of our experimental lots dried, hulled and ready for roasting, we took them to Manantiales’ cupping lab in the nearby city of Armenia. The finca has two licensed Q graders on staff who helped us to sort the coffee, roast samples and cup them.
We cupped each coffee blind, and scored them quantitatively and qualitatively, giving each a numeric score and set of flavor and aroma descriptors. Our lowest score was 8 out of 100! (Which was a joke, really- the coffee was basically ruined and tasted horrible.) Our highest score was an 89, which was a marked improvement over the control. The complete results are below.
For our first foray into experimenting with coffee, and given the improvised tools and equipment we had access to, we feel like the project was successful. We’ve been told that coffee will humble anyone who starts trying to understand and manipulate it- and we didn’t have very high expectations for our first try.
More than anything, we generated meaningful information about where to go with future experiments. Our results told us that time, temperature and bacteria all have interesting and varied impacts on flavor development. Our initial results seem to suggest that colder temperatures during fermentation result in greener, herbal aromas, while warmer temperatures create stronger fruity aromas. Changing the bacterial environment may impact coffee’s acidity and secondary aromas.
It’s clear from our results that faster processes yield better results: coffee doesn’t hold up to extended macerations the way that grapes would, for instance. With our two experiments combining freshly hulled cacao beans with freshly pulped coffee, the shorter fermentation time yielded much better results. Our over fermented or over-macerated coffee developed oniony, wine-like, moldy or earthy flavors that are all pretty unpleasant. 2 days or less at full moisture levels is a rough guide we might follow for future rounds.
More than these immediate conclusions, we learned that doing anything out of the ordinary with coffee on coffee farms in the developing world is difficult because of lack of hygiene, lack of infrastructure, lack of capital and lack of education. Exploring the nuance of each variable impacting the flavor of our experimental lots would require the ability to create a controlled, lab-like environment. Coffee farms don’t look like wineries or breweries with their shiny stainless equipment, impermeable flooring and ample supplies of disinfectant cleaners. Instead there are dirty boots walking everywhere, unwashed hands, insects, compost piles nearby… and that’s in the best of cases.
At issue is whether the increased value of coffee from applying a more refined version of one of our experimental processes would justify the investment necessary to achieve successful results at scale. We wonder whether there may be a sweet spot in working with farmers whose land happens to be at lower altitudes and therefore who can’t grow traditional specialty coffees- where the opportunity to increase value is high, since you’re starting from the commodity price. These farms are also those that would require the highest initial investment to get a project like this off the ground, however.
For farms that already produce specialty grade coffee, the benefit is harder to justify. Where buyers already pay high prices for quality coffee, the marginal quality or increased interest may not sufficiently increase margins. The market for specialty coffee is also complex: few roasters and coffee consumers are willing to spend the kind of money to support the type of unique specialty coffee we’re contemplating here- and the luxury segment is only so big.
Regardless, this subject is fascinating to discuss and we do feel that new processes should certainly become part of the coffee world in the future- whether along the lines we’ve explored or otherwise. We’re happy to continue the conversation with whoever is interested- and we do hope to take our results and use them to inform more advanced experiments in the future.
Full tasting notes for each experimental lot:
(You’ll notice a few are missing- for some reason we don’t have data for them…)
Red Bourbon:
A. Aroma: Straw, dried corn, clove, spiced: cedar, pepper. Taste: Long, agreeable aftertaste, bitter chocolate, pepper, cloves, exotic, inconsistent. 85.5
B. Aroma: Chocolate and fruity, light peach, dry, peanuts, blackberries, figs Taste: almonds and figs, velvety, creamy body, balanced fruity acidity, long and clean aftertaste 85.5
C. Aroma: Buttery peanuts, toasted hazelnuts, sweet herbal background, chocolate, almonds. Taste: Flat, watery, lacks sweetness and complexity, dry and insipid. 77
D. Aroma: Onion, malty butter, vinous-liquor, ripe fruit Taste: Light acidity, medium body, buttery cedar, prolonged chocolaty aftertaste, stinging background, onion. 82
E. Aroma: Chocolate, spices, orange peel, earthy, phenol. Taste: Moderate acidity, rough, heavy, light earth, lacks sweetness and cleanness, astringent, disagreeable. 75
F. Aroma: Herbal, dry, peanuts, caramel, dried fruits, herbal-chocolate, light vanilla, buttery. Taste: Medium acidity, juicy, pleasant dried fruits. 83
H. (one cup was oniony, two cups were earthy) Aroma: Red wine, dried fruits, bitter chocolate, raisins. Taste: clean, gripping acidity, medium bodied, dried fruits, long aftertaste, lacks sweetness. 8
Ia. Aroma: Potato, nuts, currents, pepper, pico de gallo. Taste: Vinous acidity, dried bitter fruits, light astringency. 82.5
Geisha:
1. Aroma: Chocolate, hazelnut, herbal background, caramel and vanilla. Taste: Mold, silky buttery body, high acid, non-uniform. 79You may have noticed that the labels on each of our coffees include a description of "process." When we write “washed,” “honey,” or “natural,” we’re referring to the method used to transform fresh-picked coffee cherries into dry coffee beans ready for roasting. The way coffees are processed has a huge impact on how they taste- and learning which processes you prefer will help you consistently pick coffees you’ll like.
Natural or Dry Process:
Natural coffees use the oldest coffee processing technique: you just pick a bunch of coffee cherries, leave them in the sun to dry and crack the beans out of the dried fruit afterward. Natural process coffees can have bigger body, more fruitiness and smoother mouthfeel than their washed counterparts. These qualities we love about natural process coffees were once actually considered faults- and naturals still aren’t for everyone: some people taste funk instead of fruit, or dirtyness instead of body…
Modern natural processing has become more sophisticated in an effort to avoid the development of off-flavors in the cup. Coffee farmers pay close attention to controlling the length of time the cherries take to dry, humidity, airflow, temperature and other factors.
Washed Process:
Washed coffees are by far the most common in today’s market. In the washed process, coffee beans are squeezed out of the freshly-picked cherries, and then left submerged in water for anywhere from a few hours to a few days for the pulp, or mucilage, that surrounds the beans, to dissolve. (This process is sometimes referred to as fermentation. While there is limited metabolization of sugars that does take place, the major processes are enzymatic and bacterial fermentation that basically just cause the mucilage to dissolve in the water.) Then the coffee is dried either in the sun or by mechanical means. Coffee at this stage is called “parchment” because it still has an inner, khaki-colored shell that must be milled off before the coffee is ready for sale and roasting.
Washed coffees are brighter, have more focused and cleaner flavor profiles and lighter mouthfeel. Washed coffees don’t have the funk of their natural and honey counterparts- and people disagree over whether that’s a good or a bad thing.
Honey or Pulped Natural Process:
Honeyed coffees split the difference between washed and natural coffees. In the honey process, the beans are squeezed out of the fresh cherry like in the washed process, but then the goopy, mucilage-covered beans aren’t washed but rather left in the sun to ferment and dry. There are different degrees of honey process: people refer to Yellow, Red or Black honey. The colors relate to how dark the parchment coffee becomes as it dries, to how much mucilage is left on the beans and to how long the drying process takes. Black honeys retain 100% of their mucilage and undergo the longest drying time, while yellow honeys have both the shortest drying time and keep the least amount of mucilage, and reds fall somewhere in between.
The character of honeyed coffees falls somewhere between washed and natural coffees. At times a yellow honey might taste just like a washed coffee with perhaps a slightly heavier body. Other honeys have as much or more fruitiness than some naturals.
All three processes can create exceptional coffees- and we recommend that you make sure to try them all at some point as you continue to discover more about the world of coffee.
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