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. 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.
'coffee processing' on Serious Eats
What makes coffee taste like coffee? That's a more complicated question than you might think. At every step of a coffee bean's life, something intervenes that could drastically alter its flavor: Plant variety, agricultural approach, terroir, processing, roasting, storage, and, of course, brewing all play a huge part in how your morning cup tastes. Today, let's explore one of these influences: processing.