Chilean wine has a long history for a New World wine region, as it was the 16th century when the Spanish conquistadors brought Vitis vinifera vines with them as they colonized the region. In the mid-19th century, French wine varieties such as Cabernet Sauvignon, Merlot, Carmenère and Franc were introduced. In the early 1980s, a renaissance began with the introduction of stainless steel fermentation tanks and the use of oak barrels for aging. Wine exports grew very quickly as quality wine production increased. A large number of French people immigrated to Chile during the late 20th century, bringing more vinicultural knowledge to the country. Chile is now the fifth largest exporter of wines in the world, and the seventh largest producer. The climate has been described as midway between that of California and France. The most common grapes are Cabernet Sauvignon, Merlot and Carmenère.