Green apples, pineapple, honey, vanilla, smoke, leather, chocolate, even damp earth. The diversity of flavour you can find in whisky is extraordinary, particularly when you consider it all begins with just barley, water and yeast.
When I first started enjoying single malt, one of the things that got me excited and thirsty was reading the tasting notes and marvelling at all the different flavours that could be found in whisky. What is even more impressive is that for a spirit to be called single malt, producers are only allowed to use three ingredients: water, barley and yeast.
However, when it comes to flavour in whisky, there is also a final element that is just as important: the cask used to mature the spirit. And in this email, I’d love to focus on that.
In Australia, for a spirit to be called whisky, it must be aged for a minimum of two years in wood.
Historically, it was cheaper and easier to use a barrel that had already been made and used by someone else. These were often Sherry and Port casks, but after the Second World War there was a big shift in favour of old Bourbon casks.
Into the 1950s and beyond, people were drinking less Sherry and Port, and closer ties with the US gave producers easy access to a good supply of Bourbon casks. What made this supply of second-hand casks from the US so consistent was the requirement that Bourbon producers use new barrels, meaning that once used, those barrels needed somewhere else to go.
To this day, single malt producers will still predominantly use casks that have had a past life. This means that the flavour from the oak and the barrel's previous occupant doesn't overpower the character of the whisky spirit itself.
Port casks can give lovely rich red fruit, plum and dark chocolate flavours; Sherry casks more dried fruit, raisins, figs, nuts and spice; while Bourbon casks are often all about vanilla, honey and coconut. But the flavour from a barrel doesn't just come from what it held before. It also comes from the oak itself.
As lots of wine drinkers will know, two of the main types of oak used in barrels are European oak and American oak. European oak generally has a much tighter grain than American oak and can give more tannin. Whisky aged in American oak will tend to be softer and sweeter, whereas European oak tends to be spicier, with a more savoury structure.
At Kinglake we're very focused on creating a distinctive spirit before it ever sees a barrel. But there's no denying the magic of spirit meeting oak, and over the years the two slowly become something neither could ever have been on its own.
