Riesling is a white grape variety that is believed to have originated from the Rhine Valley region of western Germany, before later being traced to the Alsace region by 1470 and Austria by 1700. Riesling is an aromatic grape variety displaying flowery, almost perfumed aromas as well as high acidity. It is used to make dry, semi-sweet, sweet, and sparkling white wines. Riesling wines are usually varietally pure and are seldom oaked. As of 2004, Riesling was estimated to be the world's 20th most grown variety at 48,700 hectares, but in terms of importance for quality wines, it is usually included in the "top three" white wine varieties together with Chardonnay and Sauvignon blanc. Riesling is a variety that is highly "terroir-expressive", meaning that the character of Riesling wines is greatly influenced by the wine's place of origin.