Indonesian coffee is full bodied, low acid, and earthy.This is largely because of how it is processed.Their semi-wet-process method actually allows the beans to begin fermenting, and if you think about it, you’ll taste exactly that when you drink it.But this is not a bad thing – perhaps an acquired taste – but those who like it, like it very much.I personally could drink a dark dirty Sumatra just about every day and not mind.Because of the low acidity and full body, Indonesians make a great coffee for blending with lighter roasts from other origins, and they balance each other out. The main varietal grown in Indonesia is the "Java" varietal, and it is rarely grown anywhere else in the world.
Bali: You are most likely to find one of two Bali coffees for sale, and they were both grown by the same organic co-op, they were just processed in two different ways.The Bali Blue Moon is the semi-wet-processed version with its musty earthy full bodied goodness.And although it pales in quality compared to a Sumatra, it is fun to drink a coffee from Bali.The Bali Kintamani is the natural processed version, which is a strange result.You still get the smoothness and the full body, but add in strange undertones such as glue, cherry, and cabbage.It is quite the experience, and worth trying for the novelty of it.
East Timor: Also sometimes sold as just “Timor”, this island produces a coffee similar to Sumatra, but with less character.It’s not as earthy tasting, and not quite as alluring in aroma or complexity.However, it often costs considerably less than Sumatra, and the best lots of Timor are an exceptional value.Fair Trade and Organic certification is reasonably easy to find.
Flores: Flores coffee is like a premium Sumatra, because it has less chaff and has been sorted by size.The downside to this is that you get a cleaner taste and less breadth of flavors in the coffee, however, it certainly stands on its own as being a quality mug of coffee.Look for undertones of cocoa in medium-dark roasts.
Java: Java coffee is almost a perfect coffee.Too perfect.The acidity is just right.The body is just right.The complexity is to a minimum. You swallow and the taste is gone. It doesn’t have one particular trait to make it shine.However, it is an extremely useful blender coffee (think Mokka-Java!) and is often the first coffee roasters turn to if they need to stretch out their supply of Sumatra.Most of the coffee is grown on government estates, and is reasonably sustainable and fair although certifications are rarely attached.The best Java is usually found on private estates and will carry organic certification.
Java also grows what is some of the best robusta on the marketplace.
Papua New Guinea: Papua New Guinea is the odd ball Indonesian.It is the only region that doesn’t use the semi-wet-process method. They also don't grow the "Java" varietal of coffee bean that all the other islands grow. And hence their coffee tastes nothing like an Indonesian!Unlike the other Indonesians, PNG shines at light roasts, with creamy, juicy, buttery characteristics.It is not earthy, has a medium body, and it is fruity but not like an African.The fruit undertones will be more like pineapple, papaya, mango, and such.Papua New Guinea grows a lot of the Jamaica Blue Mountain varietal, which, while it doesn’t taste like Blue Mountain, it is a nice coffee in its own right.I find a lot of inconsistency from one crop to another, even from the same estates or co-ops.In general, the co-ops do produce a coffee with more complexity while the estates are better at sorting and processing.But the taste varies greatly and you really just have to sample them to find out what you’re getting, as bean size and sorting don’t guarantee a good taste.
Sulawesi: Sulawesi is one of my all-time favorite coffees, and one of my all-time worst sellers.To me, it is the best of both worlds, you have the earthy full bodied Indonesian character, with undertones of orange citrus and an aftertaste of licorice.I typically recommend Indonesians be roasted dark – well into the 2nd cracks, but Sulawesi can be just as intriguing when you roast it just to the 2nd cracks, or even before it gets there. Something about a french press or pourover method works magic on Sulawesi beans, and produces extraordinary coffee.
Now the only word of warning is that there are a couple dozen small islands all surrounding Sulawesi, and they all just use the Sulawesi Toraja name even though they aren't. It is difficult to determine from the marketplace whether a Sulawesi is authentic or not, and all that really matters is the taste, but unfortunately, the outlying islands quite often grow a lower quality bean with less complexity. If you can trace your bean back to the village it is from, you are a step ahead of the competition.
Sumatra: The king of Indonesian coffee.The most common is Mandheling which just means it was grown by the Mandheling people, anywhere on the island.Fair Trade Organic certification is not difficult to find, and in general, the coffee is consistent in taste and quality despite the widespread growing region and amount of different farming groups involved.Although it is usually found roasted about 15 to 20 seconds into the 2nd cracks, I find it boring at that level, and I leave it in for a good 40-50 seconds of 2nd cracks and really let it sweat and get oily.I can do that, because Sumatra doesn’t pick up burnt tastes the way most beans would, and it doesn’t get a thin body like a Central American would at that roast level.So you get a dark smooth full bodied coffee, with some earthiness and complexity, and this is a coffee that is predictably popular anywhere you take it.It is good black or with cream, and a nice lot of Sumatra is going to have some (faint) undertones of cocoa and black cherry, while the less nice lots are going to be a bit too musty tasting and the earthiness will overpower any undertones that may be there.
Now there are other Sumatra coffees, and these are much harder to find, although generally not much more expensive. You will sometimes find one from the Batak group, which are an ethnic group residing up by Lake Toba, where the elusive “Blue Batak Sumatra” is grown.This is sometimes labeled as Lintong or Gayo. These coffees are more complex compared to Sumatra Mandheling, and possess undertones such as chocolate or cedar. They are often cleaner tasting as well, and are often best at medium to medium-dark roast levels.
Almost all of Sumatran coffee is semi-washed process, which gives it the earthy aftertaste. A handful of private estates do some fully-washed lots which are very clean-tasting coffees, with a much more herbal, butterscotch, cedarwood type of taste to them. A handful of private estates also do some natural-process lots, and these tend to also be clean and full bodied, but sweet and undertones of stone-fruit, such as plum and cherry.