Which Alcohol Content is Best?
Care for a bit more?
Do you prefer your whisky neat? Without the addition of still water? Connoisseurs often state that they don't want to water down their whisky. The argument goes that it would be authentic to enjoy the whisky the way it came out of the cask. That's how it was done in former times, and Scots still do it.
Is that true? What is myth and what reality? Why does whisky from different casks have a different alcohol content? And why are there standard alcohol contents of 40% or 43%?
Whisky is usually filled into the cask with an alcohol content of 63.5% ABV in Scotland. There is no conclusive evidence why it's done this way. There are two theories. One has to do with consumption taxes or duty. Harmonising made it easier for distillers and excise men to calculate the taxes. The second theory revolves around the former practice of distillers to pragmatically exchange casks for the production of blends. When you exchange two casks of the same size and age, both casks should roughly have the same alcohol content despise evaporation if the casks have been filled with the same alcohol content.
The argument that whisky tastes best after maturation with this specific alcohol content does not hold water (no pun intended) since no matter whether the cask is fresh or used, or small or large, the whisky is always filled in with an alcohol content of 63.5%. If it were a matter of taste, it would only apply to the whole industry in general. You can't deduce the quality of an individual whisky from this initial alcohol content.
First let's deal with the minimum alcohol content of whisky. This has nothing to do with the taste of a whisky, but is a legal requirement. According to EC directives, a whisky must have a minimum alcohol content of 40% ABV. Before EC regulations, there were whiskies in France with an alcohol content of 38.5%, which is still the lower limit for vodka. US light whiskeys used to have even lower alcohol contents of roughly 25% in the 70s.
The first instance of alcohol content correlating with quality were the 43% you can still find here and there. This alcohol content used to be common in duty-free trade. You could offer the customer a bit more quality without having to pay the high alcohol tax. After duty-free had been abolished inside the EC, these extra 3% were soon axed by the corporations. There are still 1-litre bottles in travel value, but they all have an alcohol content of 40%.
The introduction of unchillfiltered single malt whiskies in the 1990s led to a sudden rise of the alcohol content to 46%. But this also didn't happen for taste reasons, but due to a quality issue for the average consumer. Unchillfiltered whisky becomes cloudy when enjoyed on the rocks. This can be avoided by raising the alcohol content to 46%. Thus the solid particles remain solved longer and the whisky stays clear.
Alcohol content in Proof
Beside these present-day standard whiskies with 40%, 43% and 46%, there are also individual whiskies with an alcohol content of 57.1% or 57%. These 57% correspond with the 100 proof of the old imperial method to measure the alcohol content. The development of this system is also surrounded by myths. There are differences in the colour of the flame when you mix a whisky below 100 proof and one above 100 proof with gunpowder and ignite them. Below 100 proof the flame is pale blue; above 100 proof the flame is distinctly and visibly yellow. This test for the measurement of the alcohol content led to the adjustment of the proof scale with these 57% being set to 100 proof. Before scientific measurement methods were introduced, there was only underpoof, proof and overproof. Only with the advance of science could these numbers be determined more exactly, and the proof scale could be graduated. 3% ABV correspond with 5 proof. The Glenfarclas 105 (proof) therefore has the exact alcohol content of 57% + 3% = 60%.
But again, taste was not the main criterion for this specific alcohol content. The reason was rather to be distinct from competitors, who still sold their whiskies at 100 proof = 57%.
In the 19th century, when the global success story of whisky began, transport of goods was laborious and expensive. Before the invention of the industrial glass bottle, whisky was mostly transported in the very casks it had matured in. At their destination, the whisky was either poured directly or transferred into smaller containers such as jars and decanters. Since this cask strength whisky was too strong for many connoisseurs, water jars became established in the bars of the world. Now everybody could dilute their whisky with still spring water according to their preferences. But one or the other innkeeper might have lent a helping hand and already reduced the strength of the whisky when it was still in the cask.
At a rough guess, 1% of all Scotch whiskies are nowadays bottled at cask strength. There are two main areas where this happens. On the one hand, small and independent bottlers bottle the most precious among their whiskies at cask strength. Some especially small bottlers even bottle all their whiskies at cask strength. On the other hand, the large whisky corporations have adopted this trend and also bottle the outstanding part of their products at cask strength.
The pricing of these bottles is interesting. If you translate the price to a dilution of 40% or 43%, there is still a considerable surcharge. This is understandable. Naturally, the best one percent of our whisky is a bit more expensive than the standard bottling.
The question remains whether you want to dilute your whisky or not. There is a lot of theorising that a cask strength whisky contains more aromatic substances per volume and its flavour is therefore more intense. But two other physical effects speak against that. On one side, strong alcohol is an anaesthetic, a nerve poison even. The taste receptors in nose and mouth are anaesthetised by alcohol and thereby incapacitated. You taste less indeed. Strong alcohol dehydrates the cells in your mouth, which also restricts their functionality.
The second physical effect in favour of dilution is the decreasing solubility of aromatic substances with sinking alcohol content. Thus the aromas have no chance but to rise from the whisky, and that's exactly the moment at which we can absorb them comfortably with our nose.
Horst Luening, September 2016