Everybody has favorite things they love—or love to hate—in coffee. And as the so-called third-wave, specialty, progressively lighter-roasting trend has swelled, there's one part of the coffee-growing world that continues to suffer in the opinion of many finer roasters: Sumatra. Why such maligning of an Arabica-producing coffee region with a nearly year-round harvest? The answer has both to do with flavor and with our misunderstanding of where flavor comes from.

Coffee loves to borrow its vocabulary from the wine world. But the terroir—the growing region and climatic conditions' affect on flavor—is only part of why a coffee tastes the way it does. That point is stressed by one of the most well-spoken on the subject, Thompson Owen of Sweet Maria's, a home-roasting bean supplier.

Why is Sumatran coffee so contentious? Coffees in Sumatra are traditionally processed using a method called Giling Basah, or wet-hulling, which results in a coffee that leaves the farm with a much higher moisture content than other methods used more popularly worldwide.

What's the effect of this process on flavor? To generalize, coffee processed this way tend to be described as herbaceous, spicy, wild, mushroomy, funky, earthy, and other things that may or may not sound good to you. Coffees like this tend to have less brightness and acidity—many drinkers of Sumatran coffees enjoy what they feel are smoother, fuller-bodied results. Often these coffees are roasted darker to enhance their herbaceous flavors with roast-induced sweetness or a sense of richness. While many have come to love what they see as the weirdness and complexity of Sumatran coffees, others will reject them out of hand. There aren't a lot of people who fall smack in the middle.

It seems it's not as simple as coffee from a certain place necessarily tasting a certain way.

"Processing matters in really fundamental ways," says Owen, who cautions that it's easy to oversimplify our understanding of a coffee by where it was grown, rather than how it was processed. A coffee bean grown in Sumatra and processed through wet-hulling will taste remarkably different than the same kind of bean grown in Sumatra and put through the entirely different process of having the fruit stripped from the bean and the bean dried on a patio over enough time to reduce its moisture content (assuming you can keep the beans dry on the patio in the first place, which is a tall order in that part of the world.)

But it's also easy to oversimplify the effect of process. Natural process coffees, which Ethiopia has become particularly famous for by popularizing intense blueberry and fruity flavors in some coffees, can still taste different country to country, bean to bean.

"This is a really great example of the reality of coffee," Owen says. Many coffee drinkers have been taught that coffee from Sumatra comes only one way, wild and funky and herbaceous, and they'll either take or leave that notion out of hand.

Though many specialty roasters will carry a Sumatran or neighboring Sulawesi coffee on their list from time to time, they can be more challenging to sell, and taste, than more popularly understood—and livelier, sweeter—coffees currently sold from regions like East Africa or Central America.

"I'd say we're seeing more sympathy for a few Indonesian coffees from folks in 'fancy' coffee only because we're starting to see some coffees that more closely resemble the more popular flavor profiles from better known, more mainstream regions," said coffee roaster Jared Linzmeier of Amherst, Wisconsin's Ruby Coffee Roasters, which offers a coffee from nearby Sulawesi.

"Our Sulawesi Toarco coffee is very sweet and clean and is wash-processed," said Linzmeier. "It is soft and syrupy in the cup and I think folks are okay with the idea that some of the potentially savory qualities have more to do with the cultivar than processing. That is a key point to me. I like the idea that processing facilitates rather than modifies a coffee's potential expression. I'm okay with some strange flavors in the cup if I feel it represents a clear, clean representation of that coffee's potential."

If it seems like it's a bit blurry to draw lines between the bean, the ground it is planted in, and the way we prepare it before it gets to the roastery (nevermind once it's in the roaster's hands), you're right. And whether our assumptions are inaccurate, good or bad, they do help market coffee. Sweet Maria's Owen frames it this way: "When you have a coffee table and there's 10 coffees [and one] weird one—it's either going to be whipped and lashed, or people are going to be like, 'this is the greatest thing ever!' In the marketplace, it's hard to consider it alongside everything else."

Linzmier adds that harvest timing can be a factor in swaying people towards Indonesia: "Another reason people, myself included, are getting more excited about Indonesia is time of year. These coffees are arriving when many Centrals are significantly faded [in flavor], so people are looking to round out their menus with something dynamic."

While there is increasing experimentation and diversity among processing methods in Sumatra, the cultural predominance and economic advantages of wet-hulling continue to associate the region with particular flavors. Whether you like them or not, or consider them the coffee beans' "true" flavor, doesn't particularly matter.

"You describe the attributes of the coffee," said Owen. "And if people want low acidity, that's totally legitimate. I don't think there needs to be a judgment of the goodness of the coffee, and I don't think it has to be 'this attribute is better than that attribute.' There's not one template for coffee."

Have you tried Sumatran coffees from your local roaster? Found any you particularly love (or hate)?

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