Single malt Scotch whisky is one of the most revered spirits in the world. It has such scope for variation, it can offer complexity or simplicity, unbridled power or a subtle whisper. To legally be called a single malt Scotch, the whisky must be distilled at a single distillery in Scotland, in a copper pot still from nothing other than malted barley, yeast and water. It must then be aged in an oak cask for at least three years and a day, and be bottled at no less than 40% abv.
There are regional variations within Scotland, and terroir and geography play a massive part in the character of the whisky. Though in a Scotch single malt, it is the oak barrel that has the largest effect upon the character of the finished spirit, purported to be at least 60% of the final flavour.