Historians think it was shortly after the discovery of wine itself, the alcoholic product of fermented grape juice, that cultures realized its value as a trade commodity. Although wild grapes of the genus Vitis could be found throughout the known world and all could be fermented, it took some degree of knowledge and skill to turn these grapes into palatable wine. This knowledge was passed along the trading routes that emerged from the Caucasus and Zagros Mountains down through Mesopotamia and to the Mediterranean, eventually reaching Phoenicia. Specific varieties of grapevines of the V. vinifera species were identified as especially favorable for winemaking, cuttings of which were spread via these trade routes.