Tonka bean oil is extracted from the seed of the Dipteryx odorata. The oil is composed primarily of coumarin, which is used to flavor tobacco. It is neither a pressed oil, nor an essential oil, but was traditionally obtained by soaking the large, single tonka bean seed in rum or other alcohol for 24 hours, after which crystals of coumarin appear on the outside of the seed, and are collected. The seeds contain up to 46% oil by dry weight. In more recent years, most commercially produced coumarin is synthetic, which has reduced the demand for tonka beans as a crop.