Dewar’s 12 Y, a classic blended Scotch whisky, is returned to individual casks after 12 years of maturation and blending to undergo a 6-month marrying process. It is one of the best-selling blended whiskies in the world. Over a century ago, John Dewar was one of the first Scotsmen to blend whisky. He was so enamored with the result that he decided to put his name on the bottle as a mark of quality.