Filtration

A reusable filter of woven cotton or flannel, used across an unusually wide range of traditions — the Malaysian and Singaporean kopi sock, the Costa Rican bolsita, the Brazilian coador de pano, the Japanese nel drip flannel and the cloth strainer used for café Touba. Cloth sits between paper and metal: it holds back most grounds like paper but passes far more of the coffee's oils, which is why cloth-filtered coffee is usually described as fuller-bodied and rounder than the same coffee through paper. It must be kept wet or frozen between uses, because a dried-out cloth goes rancid.