Mustard plants are of three types: white mustard (Sinapis alba), which is found even in the wild in most of France, black mustard (Brassica nigra), which grows in Asia and Northern Europe, and finally Brassica juncea, or Chinese mustards, whose leaves and stems are also used in Asian cuisine. Basic Dijon mustard consists of brown and/or black seeds that are crushed and sieved before adding verjuice (juice of green grapes harvested in Autumn) or vinegar, water, salt, and a little citric acid.