The terpenoids are a major class of natural products with a range of functions in plants. In the grape, monoterpenes, sesquiterpenes and C13ânorisoprenoids are present either in a free volatile form, or bound to sugars and rendered nonâvolatile. Of the many terpenoids in grapes, only a relatively small number makes an important contribution to wine aroma. This review summarises new developments in understanding terpenoids, including the monoterpenes linalool, cisârose oxide, 1,8âcineole and wine lactone; the sesquiterpene rotundone; and the C13ânorisoprenoids ÎČâdamascenone, ÎČâionone, 1,1,6âtrimethylâ1,2âdihydronaphthalene and (E)â1â(2,3,6âtrimethylphenyl)butaâ1,3âdiene. Their origin, formation and behaviour during winemaking and ageing, and viticultural influences on their concentration, will be discussed, as well as their role in different wine styles.