Coffee from this western-most island in Indonesia is intriguing and complex due to the large number of small-holder producers and the unique "giling basah" (wet hulling) processing technique they use. At the green bean stage, coffee from this area has a distinctive bluish colour, which is attributed to processing method and lack of iron in the soil. Coffees from Sumatra are known for having smooth, sweet body that is balanced and intense. Depending on the region, or blend of regions, the flavours of the land and processing can be very pronounced. Notes of cocoa, tobacco, smoke, earth and cedar wood can show well in the cup. Occasionally, Sumatran coffees can show greater acidity, which balances the body. This acidity takes on tropical fruit notes and sometimes an impression of grapefruit or lime. Mandheling is a trade name, used for arabica coffee from northern Sumatra. It was derived from the name of the Mandailing people, who produce coffee in the Tapanuli region of Sumatra. Mandheling coffee comes from Northern Sumatra, as well as Aceh.