an ovoid. It is often used to make fresh sambal, a spicy chili condiment, hence the sambal ulek/oelek denote its process using pestle. It is also used to grind peanut and other ingredients to make peanut sauce for gado-gado. Husking and dehulling Large mortars and pestles are still commonly used in developing countries to husk and dehull grain. These are usually made of wood, and operated by one or more persons. In the Philippines, mortar and pestles are specifically associated with de-husking rice. A notable traditional mortar and pestle is the boat-shaped bangkang pinawa or bangkang pangpinawa, literally "boat (bangka) for unpolished rice", usually carved from a block of molave or other hardwood. It is pounded by two or three people. The name for the mortar, lusong, is the origin of the name of the largest island in the Philippines - Luzon. Large wooden mortars and pestles have been used to hull grain in West Africa for centuries. When enslaved Africans were brought to the Americas, they brought this technology—and knowledge of how to use it—with them. During the Middle Passage, some slave ships carried un-hulled rice, and enslaved African women were tasked with using mortars and pestles to prepare it for consumption. In both colonial North and South America, rice continued to be primarily milled by hand in this way until around the mid-1700s when mechanical mills became more widespread. Material Good mortar and pestle-making materials must be hard enough to crush the substance rather than be worn away by it. They cannot be too brittle either, or they will break during the pounding and grinding. The material should also be cohesive, so that small bits of the mortar or pestle do not mix in with the ingredients. Smooth and non-porous materials are chosen that will not absorb or trap the substances being ground. In food preparation, a rough or absorbent material may cause the strong flavour of a past ingredient to be tasted in food prepared later. Also, the food particles left in the mortar and on the pestle may support the growth of microorganisms. When dealing with medications, the previously prepared drugs may interact or mix, contaminating the currently used ingredients. Rough ceramic mortar and pestle sets can be used to reduce substances to very fine powders, but stain easily and are brittle. Porcelain mortars are sometimes conditioned for use by grinding some sand to give them