If great whisky takes time, deliberately trying to make it mature faster sounds like entirely the wrong approach. But smaller casks have played a surprisingly important role in Australian whisky, including here at Kinglake.
In an earlier email I talked about how temperature and humidity affect whisky as it ages in oak. But there is another lever a distillery can pull rather than simply relying on the weather, and that is the size of the cask.
Most Scotch producers use hogsheads and ASBs (American Standard Barrels) to mature their whisky, generally holding around 200 litres. Smaller format casks, however, can impart flavour to whisky more quickly because there is more oak surface area in contact with the spirit.
In a 50-litre cask, for example, the amount of oak surface available per litre of spirit is getting on towards double that of a 200-litre barrel.
But making whisky is about patience, right? Surely faster isn't necessarily better?
That's absolutely true. But for the Australian whisky industry to get off the ground, it needed to explore ways of creating world-class single malt in considerably less than ten years. Smaller format casks were one of the ways Australian distillers achieved this.
It doesn't come without a cost.
It can cost almost as much to have a barrel recoopered down to 50 litres as it did to buy the original cask. In the case of Bourbon barrels, you often only get one 50-litre cask from each original barrel. The angel's share can be around twice as high, and of course the resulting cask holds only a quarter of the whisky. Put all of that together and maturing whisky in a 50-litre cask can cost us around ten times as much per litre as using the original full-sized barrel.
The economics become even more extreme with the 20-litre casks that were widely experimented with in Tasmania during the early years of its whisky industry.
There is another potential problem too.
Small casks accelerate extraction, but extraction is only one part of maturation. The danger is that you can extract lots of oak character before some of the slower processes of maturation have had time to do their work. Small casks therefore require much more careful management.
Used well, however, there's no reason they can't produce exceptional whisky, and Tasmania provides some unusually good evidence of that. Sullivan's Cove, Lark and Old Kempton all successfully used smaller casks in their early years, and back in 2015 Bill Lark said of Lark's 20-litre barrels:
“Some of our best has come from the smaller 20L barrels.”
We have our own experience of this at Kinglake.
One of our most consistently well-received whiskies is Full Noise, which to date has been centred around 50-litre Bourbon casks.
When I put together a batch of our Bourbon Cask whisky, I'll usually select between five and ten barrels. As I'm working through the bond store choosing them, occasionally I'll come across a cask that stands out as a particularly good example. Those barrels get put aside and are generally used in two or three-cask batches of our cask-strength Full Noise.
With only one exception, every cask I've selected for Full Noise so far has been a 50-litre barrel.
In his Whisky Bible 2024, Jim Murray described Full Noise like this:
Nose: Huge oak interference here... but of the very best kind. The barley may be intense in its own right but the spices fired into it from the casks agitate matters wonderfully. But to keep things in check, the vanillas also stretch into ulmo honey to complete a very satisfying performance on the nose...
Taste: Such succulence: it is like sucking on an alcoholic throat lozenge. Early on there are some mild bourbon messages being sent, mainly around red liquorice and vague hickory. But, again, it is the honey which stars, catching on to the oils and spreading purposefully around the palate, keeping a close eye on those busy spices;
Finish: Just ridiculous layering on a finish which seems very reluctant to end. The spices carry on their profound work. But, as earlier the ulmo honey, now thickened by a heather honey back up, is more than compensating. But neither can stop the odd pulse of barley which perfectly fits the bill. An astonishingly beautiful fade...
“Stupendous.”
I think that's really the lesson with small casks. They're not a shortcut to making good whisky and used badly they can very quickly become too much. But watched carefully, they give us another tool to shape the whisky we want to make. Because in the end, great whisky isn't about how big the barrel was or how long it stayed there. It's about what came out.
