Between 15-20 years. According to the Baidu Encyclopedia information, Macallan Blue Diamond refers to Macallan 12-year-old single barrel, which is a single malt Scotch whiskey. There is no specific year, and the age is between 15-20 years. Macallan Blue Diamond adopts a new bottle design. The entire bottle is dark blue. The choice of this color has a very unique meaning, representing the three main ingredients of Macallan single malt whiskey: barley malt and water. and air.