The Fifth Ingredient: Time

Does age equal quality?

Well, Tommy Dewar, the flamboyant socialite who elevated Dewar’s White Label to global status, certainly believed so, it would seem. He was famous for his witty aphorisms, known by the international press as ‘Dewarisms’, one of which was: “We have a great regard for old age when it is bottled”. Although in another he qualified the first with: “Respect for old age does not extend to eggs”!

‘Age’ translates as ‘length of time maturing in cask’ – whisky does not continue to mature in bottle [although several of my learned colleagues would debate this, referring to it as ‘old bottle effect’, but even if we accept this possibility the changes are very small].

It has been said that “time is the fifth ingredient in developing flavour in malt whisky” – the other ingredients of course being malted barley, yeast, water and peat. While this is an attractive metaphor for maturation, it does not mean that more time automatically guarantees better whisky. There are many other factors involved, not least the nature of the cask – American or European oak? Ex-bourbon or ex-sherry seasoned? First-fill or refill? Size? – and perhaps also the location, architecture and micro-climate of the warehouse.

Casks perform three basic functions: adding desirable flavours (and colour), removing undesirable flavours (mainly sulphur compounds) and encouraging oxidation and esterification (complexity). Chemists term these ‘additive, subtractive and interactive mechanisms’ and rate casks according to how ‘active’ they are likely to perform.

The fresher (i.e. first-fill) and smaller the cask, the more active it will be. After three or four fills its activity will be much diminished, until it is deemed to be ‘exhausted’ and is either ‘rejuvenated’ or scrapped. The micro-climate and humidity of the maturation warehouse also influences the speed at which the spirit matures and its ultimate flavour.

For example, spirit first-filled into a small cask (octave and quarter cask, both around 50L, or 200L barrel) will mature its contents much faster than the same spirit filled into a larger refill cask (250L hogshead, or 500L butt or puncheon). The faster maturation can produce terrific whisky after about 5 years, but it tends to lack depth and complexity; while slower maturation in a larger, refill, cask allows for gentle interaction between wood and whisky, changing the chemistry of the spirit and integrating flavours to produce a desirable balance between the original ‘distillery character’ of the whisky and its ‘mature character’.

This is important. The flavours of very old whiskies (>30/40YO) tend to merge, so they lose distillery character and it is difficult to tell where they have come from, and they can become dominated by flavours from the wood – not necessarily ‘oaky’, but more tannic/dry. They also lose strength (the ABV reduces as the whisky matures, at different rates according to the micro-climate of the warehouse), ultimately becoming flat and dull. If the strength dips below 40%ABV the liquid can no longer be labelled ‘whisky’.

Maturation is a complex process – and an expensive one, with casks losing volume year by year (the ‘angels’ share’) as well as strength – but it plays a crucial role in developing the flavour of the final product and justifies the claim that it is “the fifth ingredient”.

The finest whiskies are ‘well aged’, but it is impossible to say ‘for how long’ to achieve this. There was a school of thought in the 1960s which spoke out against ‘the tyranny of twelve’ and believed whisky was better bottled at ten years or even eight. I have spoken to at least one experienced distiller who maintained that maturation had peaks and troughs, and another that bottling at uneven years (13, 15, 17 etc) was not a good idea.

It goes without saying that we have to pay more for long aged whiskies, and some of these have been the finest malts I have ever encountered…But not all.