Single Malt whisky is one of the most revered spirits in the world. It is exclusively made from barley, which is quite a cheap product. A bottle of The Macallan 1926 60-year-old recently sold for $1,512,000 in auction, marking the largest single sale ever for a bottle. Over the past 50 years, single malts have become increasingly popular. Scottish single malt exports grew by 14.2% in 2017 to reach nearly $1.5 billion.

Glenfiddich distillery in Scotland is the world's largest exporter of single malt. Started in Dufftown in 1886, it ships 1.2 million 9-liter cases each year. Making single malt is a difficult and lengthy process. Barley is ground down and added to spring water. Heated to 64°C, it turns to sugar, dissolving into a fine sweet, tangy liquid called wort. The wort is drained, cooled, and passed into wash-backs. This is heated and condensed in copper wash stills for its first distillation, and a second time in spirit stills. This spirit trickles into the spirit safe, ready for maturation, and then is batched in casks with spring water.

Casks spend years in the warehouse, maturing into a single malt. An aged 30-year maturation can have 30% to 40% of the alcohol evaporated in the barrel, or over 1% each year of the whisky’s life. This is because of "Angel's Share" — the natural evaporation of the liquid into the atmosphere over time. So older whiskies are expensive not because they’re old, but because they are rare. Fashion, and the collector's market, also have something to do with the rise in popularity.

Christie's Director of Wine Tim Tiptree oversaw the sale in 2018 of The Macallan 1926 60-Year-Old, which sold for $1,512,000 to a private buyer. According to Tim, the collector's market will continue to grow. India, China, and Japan, are now main players in the single malt market. Particularly successful is the Yamazaki distillery in Osaka prefecture. Rare whiskies from their collection of single malts now sell for thousands of dollars. We tried a 12 year-old single malt worth $36, and the 50 year-old bottle worth $30,000.