Cocoa is the dried and fully fermented fatty seed of the cacao tree, from which chocolate is made. (The word "cocoa" is simply a derivative of "cacao".) "Cocoa" can often also refer to the drink commonly known as hot chocolate; to cocoa powder, the dry powder made by grinding cocoa seeds and removing the cocoa butter from the dark, bitter cocoa solids; or to a mixture of cocoa powder and cocoa butter. A cacao pod has a rough leathery rind about 3 cm thick (this varies with the origin and variety of pod). It is filled with sweet, mucilaginous pulp called 'baba de cacao' in South America, enclosing 30 to 50 large almond-like seeds (beans) that are fairly soft and pinkish or purplish in color. A powder is a dry, bulk solid composed of a large number of very fine particles that may flow freely when shaken or tilted. Powders are a special sub-class of granular materials, although the terms powder and granular are sometimes used to distinguish separate classes of material. In particular, powders refer to those granular materials that have the finer grain sizes, and that therefore have a greater tendency to form clumps when flowing. Granulars refers to the coarser granular materials that do not tend to form clumps except when wet.