An optional step in chocolate manufacturing, Dutch processing is accomplished by treating the cacao with an alkali, usually potassium carbonate. Dutch processing may be carried out at various stages by the chocolate manufacturer, including treating the whole beans, nibs, chocolate liquor, or cocoa powder, although it is most often the nibs that are treated. The primary function of Dutch processing is to reduce the acidity of cacao; it also noticeably darkens the color. Dutch processing is not frequently used in the manufacture of chocolate. It is, however, frequently applied to cacao that will be pressed to separate the cocoa butter from the cocoa powder. Manufacturers press chocolate liquor because they need extra cocoa butter to manufacture chocolate. In a manner of speaking, then, cocoa powder is a by-product of the chocolate-manufacturing process and is not likely to be made from the highest-quality cocoa beans—those used to make chocolate. Usually the lower-quality, more acidic cacao is used for pressing. Dutch processing removes excess acidity and sour flavors and gives the cocoa powder a darker color, increasing its visual appeal. Most people would agree that while Dutching makes cocoa powder look more like chocolate and makes it less sour tasting, it does not make the cocoa powder taste more like chocolate. Any chocolate or cocoa powder that is Dutch processed must indicate on the label that it has been treated with an alkali.