Although cask strength is often equivalent to high proof, that’s not always the case. Some cask-strength whiskies soar to 60% ABV and higher, while others resided precariously close to the legal minimum of 40%. The variance is due to many factors: the liquid’s original strength when it was filled into cask, the length of time it spent aging and conditions – including climate, warehouse type, cask type, and warehouse location – under which it matured. As a whisky sits in the cask, its ABV is affected due to the evaporation of liquid known as angel’s share. In hot, dry climates, the cask loses water from the solution at a faster rate that is loses alcohol, so the whisky’s alcohol strength increases over time. 

In Scotland (or Japan), which is humid and temperate, as cask’s liquid evaporates, the alcohol strength of the contents decreases. The Yamato 2018 Special Edition is carefully crafted at the Yamanashi Prefecture Distillery by the Master Blender. First, he selects 20 barrels according to their complementarity and aromatic profile. Only 5 to 8-year-old barrels make the cut for this special blend. Then the Master Blender sets out to create Yamato’s central theme of intense fragrance. He blends his selections to maximize the aromas of citrus, wild flowers, and dried fruit, all while maintaining the predefined whisky proportions (60% grain and 40% malt). As a finishing touch, the selected barrels are poured into a single vat and left “to marry” for several weeks. Yamato Special Edition whisky is released at cask strength, meaning it has not been watered down after being dumped from the barrels it was aged in.