The 3 year rule for aging whisky in oak has only been around for a short while (given that distilling whisky in Scotland commenced over 500 years ago).
This is from the SMWS archives;
The first reference to the benefits which maturation brings to malt whisky is in Elizabeth Grant of Rothiemurchus’ Diary of a Highland Lady where she recalls how she sent ‘pure Glenlivet whisky’ to her father in Edinburgh for the entertainment of King George IV during his visit in 1822. Her instructions were to empty her ‘pet bin, where was whisky long in wood, long in uncorked bottles, mild as milk, and the true contraband gout in it’.
But although connoisseurs and, later, blenders appreciated the benefits, the requirement to mature whisky prior to sale was not enshrined by law until 1915. Prior to this, spirits could be sold as they mainly were in the 18th century, ‘fresh from the still’.
Today both malt and grain spirits made in Scotland must be matured in oak casks for three years before they can be dignified by the name ‘Scotch whisky’. The three year rule was introduced by the Immature Spirits Act (1915) and arises from a face-saving deal struck between the whisky trade and Lloyd George, then Chancellor of the Exchequer. It is a good story.
Lloyd George was an obsessive anti-drinker with a temperance movement background. Believing that ‘Drink is doing more damage in the war than all the German submarines put together’, as he stated in a speech at Bangor in February 1915, he first proposed total prohibition of alcohol for the duration of the war, then the abolition of spirits, then the nationalisation of the entire licensed trade, then the imposition of double duties (which was effectively prohibition by price). As might be imagined, this met with considerable public hostility, and since the Government was not strong enough to force through the measure without the support of the Irish National MPs, Lloyd George had to compromise.
The architect of the compromise was James Stevenson, a director (later Chairman) of Johnnie Walker, who had been co-opted by Lloyd George to run the ministry of Munitions, and who did such a good job there that he was later made a peer. He coolly pointed out that a ban on distilling would mean no alcohol for high explosives, no fusel oil to coat aeroplane wings with dope, no constituents for anaesthetics and no yeast for baking bread (a major bi-product of grain distilling).
Privately he referred to the Chancellor’s obsession as ‘the blustering, humbugging interference of a temperance minority which thinks it is going to abolish thirst’. His colleague ‘Restless’ Peter Mackie of White Horse Distillers was even more outspoken: he declared Lloyd George’s views to be those of ‘a faddist and a crank, and not a statesman’.
‘But what can one expect of a Welsh country solicitor being placed, without any commercial training, as Chancellor of the Exchequer in a large country like this? I might as well bring into my business and place at the head of it a bootmaker or shoemaker or country solicitor, and any man will know how incompetent he would be for the job’. Would he get away with such outspoken views in modern Scotland, I wonder?
Anyway, Stevenson proposed a face-saving alternative, based on a scheme that had been earlier urged by Mackie – long a vociferous campaigner against immature spirits, by which he meant grain whisky – and recommended that taxation be on a sliding scale. The Chancellor’s punitive duty should apply only to spirits under six months old, and should reduce on a sliding scale until the whisky was over five years old, when the original duty would remain. In the event the Government opted to ban the sale of spirits under three years old. Why three years, rather than two or five?
The temperance movement had long maintained that immature spirits (under two years old) caused more drunkenness than those over two years. Peter Mackie himself advocated three years, and attacked ‘raw whisky’: ‘Experience teaches that most of the riotous and obstreperous behaviour of drunks comes from the young and fiery spirit which is sold, while men who may over-indulge in old matured whisky become sleepy and stupid, but not in a fighting mood’. Is this the experience of members of the Society?
By 1915 experience had taught the respectable blenders that fillings over three years old made for smoother, more delicately flavoured blends, and during the past twenty years, work on the chemistry of maturation shows why.
Immaturity declines dramatically during the first three years of maturation in a first fill or rejuvenated cask (i.e. what is called an ‘active cask’; the immature period is longer – up to twelve years – in an ‘inactive cask’ which has been much-refilled). During this early period of maturation, immature off-notes and more volatile alcohols evaporate through the cask walls, while sulphur compounds (and other undesirables) are absorbed by the char on the inside wall of the cask.
In short, the cask ‘subtracts’ immature elements. As maturation proceeds, it ‘adds’ flavours from the wood (the most important compounds are vanillin and oak lactones, which lend sweetness) and if the cask has previously contained sherry, wine residues will also be drawn from the wood. Finally, and simultaneously, an ‘interactive’ reaction takes place between the spirit, the additive compounds and oxygen, giving fragrance, delicacy and mellowness. As Sir James Stevenson, as he then was, stated to a trade audience in 1920: ‘There is no greater enemy of Pussyfootism than good liquor. Served under good conditions it will withstand all attacks’. Amen to that!