By Kenneth Davids
aficionados often assume that coffees from various origins taste different
purely because they are grown in different climates and soils or produced
by different botanical varieties of Coffea arabica.
Obviously both assumptions are true. However, we
often overlook the influence of how coffee beans are processed, or
stripped of their fruit and dried. This procedure has a key impact
on how coffees ultimately taste in the cup. I'm particularly convinced
that the unique cup characteristics of traditional Sumatra coffees
their heavy body and deep dimension owe more to the
unorthodox methods Sumatrans use to remove the fruit from the coffee
and dry it than they do to characteristics imparted by soil, climate
and botany. Certainly Sumatras processed by the standard large-scale
wet method, like Gayo Mountain Washed, tend to medium body and a rather
delicate flavor when compared to the heavy-bodied, tawny-beaned Mandhelings
and Lintongs processed and dried by traditional methods.
Thirty years ago many of us in the infant specialty
coffee business assumed that there were only two ways to process coffee:
by the dry method, in which the coffee beans or seeds are dried inside
the fruit, or by the wet (or washed) method, in which the fruit is
removed from the bean in careful steps before drying. In fact, there
appears to be an almost infinite variety of nuances, compromises and
variations in processing, almost all of which affect flavor.
And Sumatra is home to several of these compromises
and variations. The many mysteries and intricacies f Sumatra processing
and drying procedures are too complex and problematic to go into in
detail here. But it does appear that all Sumatra arabica coffees have
their skins removed immediately after picking. In other words, no
Sumatra arabicas are dry-processed in the traditional sense of the
term, meaning none are dried in the whole fruit as are traditional
Brazils, Ethiopia Harrars, and Yemens.
what happens to Sumatra coffee after the skins are removed from the
fruit but before the beans are dried?
All of the small Sumatran farmers I visited some years ago
proceeded using a simple, backyard wet method. After removing the
skins from the coffee fruit using simple (often homemade) machines,
they fermented the slimy beans overnight without adding water (a procedure
called dry-fermenting), then washed off the ferment-loosened fruit
pulp in water from a creek or well before putting the coffee out to
dry. This simple procedure technically qualifies these coffees as
washed or wet-processed coffees.
However, the simply backyard scrubbing hardly removed
all of the pulp, and some remained in contact with the beans, promoting
a ferment taste that, in traditional Sumatras, can range from fruity,
chocolaty and complex to flat-out rotten.
(By the way, several second-hand accounts sent to
me by others describe Sumatran farmers who remove the pulp from the
skinned fruit by either rubbing the beans on a mat or rubbing them
with sand. It is not clear whether this mat-or-sand removal process
happens after the coffee is dried with the pulp still attached (which
would make these coffees semi-dry processed), or after the pulpy coffee
has been fermented overnight, as I witnessed.)
Finally, and still further complicating the
picture, are at least one or two larger Sumatra mills that process
the coffee by what we might call the "classic" semi-dry
method. I am told that these mills proceed much like large mills do
in parts of Brazil: remove the skins from the coffee fruit, dry the
beans in the slimy pulp, and then remove both dried pulp and inner
skins by mechanical milling.
Regardless of which of these three methods is
pursued, note that the sweet, fruity pulp remains in contact with
the bean without dilution for a considerable period of time, undoubtedly
contributing to the deep-toned, heavy-bodied profile of traditional
Sumatras, while blunting any tendencies to dry, acidy brightness.
For a final flavor twist, we have the unorthodox
Sumatran drying procedures. Small- grower Sumatra coffees, rather
than being put out to dry once and decisively, appear to be dried
in stages, first for a few hours by the growers, then for a day or
two longer by a middleman, then for a third and final time in the
ort city of Medan by exporters. This haphazard drying procedure is
undoubtedly one source of the hard, mildewed taste of inferior Sumatras,
since it allows plenty of time for development of musty or other hard
On the other hand, it also might also be a factor
in the development of the heavy body of the best traditional Sumatras.
Furthermore, when the musty tones are mild and layered atop a basically
sweet cup, we get the intriguing flavor notes that many professionals
and aficionados admire in traditional Sumatras: malt, spice, smoke,
new leather, pipe tobacco, and (when the musty coffees have been dried
directly on the ground) leaf, humus and earth.
All of this layering of fermented fruit and
rich mildew-cum-spice, plus a syrupy mouthfeel and full body, are
what Alfred Peet and Erna Knutsen valued when they first introduced
premium Sumatras to the fledgling American specialty coffee industry
many years ago. To me, the proper analogy for this great origin is
Scotch whiskeys and their peaty, slightly fruity, smoky complexity,
not wines. Save the wine analogy for Costa Ricas or Kenyas.
So far as I can tell, this richly ambiguous
complex of flavor notes continues to be what American professionals
and aficionados look for in Sumatras. I hope the traditional Sumatra
character survives the well-meaning, thankfully sporadic efforts of
commodity coffee people and cupping purists to improve it out of existence.
So far as I am concerned, we should be figuring out how to refine
and systematize the traditional Sumatra character rather than turning
Sumatras into a weak imitation of other origins. Certainly fine Sumatras
attract higher wholesale prices than most clean, high-grown Central
America coffees. It's not because the Sumatras better, but because
they impress in a different, and often fascinating, way.
Davids is a coffee expert, author, and co-founder of the Coffee
Review, the world's leading coffee buying guide. His books include:
A Guide to Buying, Brewing & Enjoying," "Espresso:
Ultimate Coffee" and "Home
Coffee Roasting." All titles are available on espresso101.com.
Click on the above links to buy.