Caffeinated Curiosity

We opened a box last week containing three one-pound bags of green coffee beans from El Salvador. Those beans, which arrived in the mail, would be roasted, ground and brewed by us so that we could judge how three common but different processing methods – washed, semi-washed and natural – can affect the flavor and aroma of coffee. Each sample came from the same plot and was harvested on the same day.  The only difference was how each had been processed at harvest. 

 

 

Eager to rate our results, we cranked up some tunes, fired up the roaster, and got to work.  

 

 

A coffee’s flavor is the result of, or can be affected by, several things – the biggest factors being where a coffee is grown, the species and cultivar of the coffee, and how that coffee is processed at harvest. The roasting process and brewing method, of course, also affect flavor. But we’ll save that for future posts. 

 

A coffee planted in one location will likely have flavor characteristics different from that same type of coffee planted somewhere else – whether it’s just over the hill, across the creek, in an adjacent field, or at different elevations or latitudes. The flavor of an heirloom Bourbon coffee grown at one elevation, for example, might be drastically different from that same coffee grown at a higher elevation on the same estate. It’s a matter of terroir (pronounced ter-wah), a concept that is increasingly being applied to coffee, but one that has long been understood by folks familiar with grape-growing for wine production.  

 

Put simply, terroir refers to those elements in growing that are beyond human control – climate, soil type, topography and surrounding plant life. Terroir typically dictates what species and cultivar of coffee is grown and, more often than not, determines what processing method is used to clean and dry the coffee.  That said, terroir plays a vital role in the character of a cup of coffee.     

 

Aside from terroir, another factor affecting a coffee’s flavor is the plant itself. There are hundreds of varieties of coffee, and each coffee carries a name that identifies it as unique – Bourbon, Catuai, Caturra, Typica, Pacamara, Gesha, etc. – but all are varieties of the same genus: Coffea.  

 

Think dogs. True, all dogs are dogs. But a Chihuahua ain’t no German Shepherd, no matter what it thinks. 

 

 

The third flavor factor – and the one we focused on because it was the only thing differentiating each sample – is processing.

 

As mentioned earlier, there are three major methods commonly used to process a coffee cherry into a green coffee bean – washed (or wet-processed), semi-washed (or pulp-natural), and natural (or dry-processed).  

 

Now, a quick-start guide  to each process. 

 

Washed:  Soon after picking, the skins are removed from the ripe coffee cherries (the fruit of the coffee plant that contains the beans). The beans are then pulped, which removes much of the fruit from around a cherry’s twin beans (or single bean in the case of a peaberry).  The remaining pulp is loosened from the bean, washed away, and the clean beans then dried.  

 

Once dry, a papery parchment skin surrounding the beans remains, but it, too, is removed. The beans are then sorted, graded and bagged for shipment.  This is the most common method for processing specialty coffee.

 

Semi-washed:  As with washed coffees, the cherry is skinned and the bean the beans are pulped.  The remaining pulp and mucilage clinging to the bean is then partially dried for a day or so before the beans are cleaned and then allowed to finish drying.  This method is less common than the others, but is the traditional method of choice among some small-holder farmers in Indonesia and Brazil.

 

Natural: The original method for processing coffee beans, this  process involves allowing the fruit to dry around the bean until the cherry becomes hard and pod-like, then hulling the bean from the dried fruit, either by hand or mechanically. This method typically produces a fruity, somewhat wild- and rustic-tasting coffee. These flavors result from prolonged contact between the bean and the sweet, drying fruit, as well as tainted or under- and over-ripe coffee cherries that are difficult to sort from the harvested lot.  

 

Because this type of processing is hard to control, natural processed coffees are a grab-bag of flavors. One batch can produce remarkable flavors, while another produces terrible results. This unpredictability has led most growers to abandon natural processing.   

 

 

Our three samples – each an heirloom Bourbon cultivar known for sweetness, superb balance and nice acidity – were grown and harvested together on the same plot at the Finca El Manzano estate, located in the Santa Ana region of El Salvador.  All things being equal, our coffees would typically share the same flavor profile. But, because each was processed using a different method, we expected each sample to be unique. 

 

To begin with, we roasted each sample to the same visual roast level, opting for a light roast to bring out more of the coffee’s true characteristics, and to best show how the different processing methods affect roasting and flavor in the cup.  

 

Each sample, as we expected, reacted differently to the roasting process due to the effects of the processing methods on the beans.  The washed coffee required more energy to carry the roast through to the end,  while the semi-washed coffee required less,  and the natural even less than the semi-washed. 

 

Cupping the coffees in order from washed to natural, the first thing we realize is that qualities typical of a Bourbon coffee are apparent in each sample.   Each has a nice, bright acidity, with the washed sample being the brightest and most straightforward.  The acidity doesn’t fade too much as we progress through each sample, but it becomes more complex, slightly rustic, and not so “in your face” as the washed coffee.  Put simply, the brightness in each cup becomes more balanced. 

 

Another similarity we notice in the three coffees is sweetness.  The sweetness increases and becomes more raw and complex as we progress from washed to natural.  The complexity in the semi-washed – and even more so in the natural – is built strongly around jammy fruit notes. It’s interesting to see how the similar flavors in each cup get increasingly more complex and fruity as we progress through the samples.  You can actually taste how the sugars and enzymes from the coffee skin and fruit have increasing influence on the final cup the longer (to a point) they are in contact with the coffee bean.

 

DARE TO BE DIFFERENT

 

This exercise illustrates just one of many factors determining how a coffee will be perceived in the cup.  A single change resulted in three totally unique cups.  

 

Coffee grows in more than 60 countries, and within those combined borders are countless micro-climates that support hundreds of unique coffee cultivars. Considering, too, the various processing methods and inability to exactly duplicate each of those methods, it’s little wonder there are thousands of unique coffees on the market each season – and each different from any coffee available before or again.  

 

So, next time you enjoy a cup of coffee . . . get lost in the ritual, take in the aroma and really taste it.  Realize that the moment is fleeting, and the cup is totally unique. It can never be duplicated. 

    

– Zack Burnett, roastmaster

Bold Bean Coffee Roasters

Jacksonville, Florida