Sumatra

Growing Regions

The most common brand/region is Mandheling which just means it was grown by the Mandheling people, anywhere on the island, but most commonly in the middle and southern areas.  The Gayo people also grow coffee, and mostly live in the northern area of the island, and often with better results.  The Batak people also live in the northern part of the island and are well respected for their coffee harvest.

Roasting Guide

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.

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.  However, if you get a washed bean (opposed to wet-hulled) in your hands, you want to give it a medium roast -- barely into 2nd cracks -- and appreciate the acidity and cedar sweetness they can offer.

A natural-processed and honey processed Sumatra is not common, but they are nice in a light to medium roast, and can make for a fantastic espresso, or complex mug of coffee.  

Manual

The king of Indonesian coffee. 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.  Sumatra beans are notoriously ugly, often with broken and discolored beans