Indonesians are available as a unique semi-washed process and (rarely) fully-washed coffees. Semi-washed coffees are best described as "wet-hulled", localy called Giling Basah, and will have more body and often more of the "character" that makes Indonesians so appealing and slightly funky. In this process, the parchment coffee (the green seed with the parchment shell still attached) is very marginally dried, then stripped of the outer layer, revealing a white-colored, swollen green bean. Then the drying is completed on the patio (or in some cases, on the dirt), and the seed quickly turns to a dark green color.
There is a tendency to over-roast Indonesians.
The reason is that they don't show as much roast color, and have a mottled appearance up until 2nd crack and even a bit into it. Don't let this make you think you have to roast them dark (although they can be nice this way too). Great Indonesians will be wonderful roasted just to the verge of 2nd crack but NOT into it at all. So ignore the wierd beans you see green, and ignore the mottled appearance of lighter roasts, and focus on the what you get in the CUP.
With prices high, you expect quality would be up to, but in general this is not the case: what's the incentive to pick and prepare the coffee better when the market guarantees a premium anyway? It's why we buy very selectively from Sumatra and cup our lots hard. What I have seen is blends of old crop and new crop early in the Grade 1 window (Nov-Jan in particular), which is a deceptive practice. Nonetheless, roasters need Sumatra and I am sure someone buys it ... someone who doesn't cup their lots that is! Problems aside, we have been able to find great Sumatras in both the rustic and the fancy triple-pick categories because we have established good relations directly with the sources.
Mandheling is an older Dutch spelling of Mandailing, which is an ethnic group, not a region. Here is an interesting anecdote on the use of Mandheling in the coffee trade. The grading of Sumatra coffees can be confusing. Many of our lots are standard, old-style Grade One grades that result in the classic, rustic, earthy flavor profile. But we also offer many super-grade lots throughout the year, so-called Triple-Pick coffees.
These can be as complex, and intense, or sometimes more refined and broader in the overall range of flavors. For more about the different styles and classes of Sumatra, here are some additional comments. I also included a google map marking Takengon and Lake Toba here. For more pictures of Sumatra than you would ever care to see, visit our travelogs for the Lake Toba- Lintong area, and the Lake Tawar-Aceh area.