We visited the Santa Ana Estate of the Undurraga Winery (recently sold to new Chile and Columbian owners) in the Maipo Valley, 34 km outside Santiago. It was a fairly typical wine tour with the highlights being the tasting of different grapes, the contrast of leaf types, and tasting Carmenere wine. Their oldest vines are 40-year old cabernet sauvignon. Our guide noted the differences between American and French oak barrels ( American Oak – larger pores, stronger flavor, barcoded; French Oak – smaller pores, more delicate, vanilla) and said that they pay $700 for new barrels but sell the old barrels for only $10. I noticed they store wine in floating roof stainless steel tanks.