Cask Life – 17.04.20 by Tim Foster – Sales Manager, Lindores Abbey Distillery
I am a maturation geek. There, I said it. I truly am. And I’m ok with that.
We’re onto my favourite Whisky topic: Cask life and where the ‘magic happens’. I’m so interested in the effects of oak on maturing spirit that I wrote a paper during my masters. Sad huh!?
I guess the infatuation with cask life started when I noticed that not all whisky is the same colour and someone pointed out they’re matured in different casks. Up until that point, it hadn’t even crossed my mind… why would it I suppose!?
Roll the clock forward and my introduction to the Scotch Malt Whisky Society and something called ‘Single Cask Whisky’. I heard bold statements claiming that two identical casks, filled with the same spirit on the same day can produce totally different Whisky. Mind. Blown. How exactly is that possible? Glad you asked…
In the Whisky industry we typically use casks made from 3 different species of Oak tree, quercus alba (American White Oak), quercus robur & quercus petraea (European Oak). More recently Japanese Oak quercus mongolica (Mizunara Oak) has gained favour, but is not ideal for maturation.
Why these species? In Scotch Whisky making we don’t tend to use virgin oak casks (those which have never been used before). We tend to source casks from the USA and Spain. In the USA, Bourbon legislation designates that they must only use Virgin Oak Casks to produce Whiskey (a throwback to the end of prohibition). Luckily in Scotland we’re able to use a cask more than once so when finished with in the USA they get shipped to us to fill. In Spain, Sherry Wine is matured in casks and when they’re finished with those casks… yep – we take em too.
Not all trees are the same
This next statement is common sense, but unless you’ve actually sat and pondered it might never occur to you. ‘Not every tree is the same’. I told you it was pretty obvious. So what do I mean? Well, think about it. A tree in the centre of a forest surrounded by larger trees with a bigger canopies will not get as much sunlight as the surrounding trees. Maybe a particular tree is shielded from the wind. These small nuances affect how the tree grows and thus the composition of the wood inside the tree. It’s fibres may become more tightly bound, or there may be more knots etc. Each tree is unique.
Turning a tree into a cask
Even more opportunities to affect the aroma, flavour and colour of mature Whisky arise when the tree is turned into a cask. In the USA they kiln staves to reduce their moisture content, whereas in France they (mostly) naturally season them like we do firewood. Staves left to season become heavens for ‘microflora’ (a nice way of saying mould). The ‘microflora’ then interacts with the maturing spirit, adding yet more complexity.
Then we have the toasting/charring process, whereby the insides of the formed cask are burned to specification. Dependent on the level of toasting or charring the wood fibres can either end up lightly toasted or totally burned. This heating process is called the maillard reaction, it’s basically what happens when we toast bread or cook a steak. You might be thinking ‘why on earth are they burning the casks?’. Well, just as bread and meat turn sweater when browned so too do wood compounds (things like lactones and lignins). The ‘carbonised’ oak also acts as a catalyst that removes impurities, basically helping to remove some ‘immature’ spirit characteristics. Win/win.
I’m not going to go into too much detail here. Basically 3 things happen to spirit that is maturing in the cask, firstly some ‘stuff’ (chemical compounds) disappears or is removed (either it evaporates or the cask removes it), then some ‘stuff’ gets added when the spirit extracts ‘stuff’ from the oak (lactones, lignins, ellagitannins thingies etc), lastly some of the ‘stuff’ turns into new ‘stuff’ – (spirit and oak compounds turn into new compounds). This bit is totally fascinating and also complicated. Basically ‘stuff’ happens.
What came before
The casks previous contents have a MASSIVE effect on the maturing spirit. Also worth noting is this, not all bourbon tastes the same and not all sherry tastes the same. Sherry for example can range from extremely dry to super sweet. Then when we look at the use of Port, Wine, Cognac, Rum and Beer casks things get really interesting. In fact, the regulations were recently relaxed and Scotch can now be aged in yet more casks – tequila finish anyone?
The sweet shop
I regard myself as incredibly lucky in a great many respects, one of which is that I work at a Single Malt Whisky distillery and that I have (almost) unfettered access to our warehouse. This means that I get to work alongside our Distillery Manager – Gary Haggart and Elliot Wynn-Higgins our Cask Custodian. Elliot and Gary have spent the last two years forging relationships with some of the very finest best cask suppliers around. Carefully selecting the best possible wood to fill spirit into, as a result our warehouse is filled with a mouth-watering assortment of incredible casks. The diversity and individuality of some of these casks is simply outstanding, one thing is for certain we’ll have some really exciting Whisky to release in the years to come.
It would be remiss of me to conclude this blog on cask life without a nod to our ever growing group of private cask owners. Whisky enthusiasts from all over the globe have invested in casks, that sleepily sit maturing in our warehouse. It won’t be long until they’re casks come of age and they can bottle their whisky to share with friends. What an incredible occasion that will be. Slainte’, Tim
Cask Ownership at Lindores Abbey Distillery
The distillery is of course currently closed but you can still chat to Elliot, our Cask Custodian about our cask ownership scheme and what is involved. We still have a lot of exciting projects going on with different types of casks coming through – but they are all very limited so get in touch if you would like to explore different opportunities within the whisky world. You can contact Elliot on firstname.lastname@example.org or find out more at https://lindoresabbeydistillery.com/welcome-lindores-abbey-distillery/cask-ownership/