Every Scotch is distilled in Scotland and by law is aged for at least 3 years in oak barrels. Blended scotches refer to a spirit that is composed of whiskies from more than 1 distillery. Much of the flavors and characteristics of a whiskey are drawn up from the wood that the spirit is matured in. Oak is the wood used most often in the maturing of spirits due to its durability and high level of natural occurring oils. These oils, called vanillins, are the main component in imparting flavor on the spirit aged within the barrel.