90° and 100°, and cask strength

April 7, 2022

Smögen has typically only made and released batched bottlings that were never intended to be repeated. The reason for this has been that Smögen only began production in 2010 and is thus a young distillery – and with limited mature stock available, the focus of maximizing quality and strength of character meant that one-off batched bottlings (or Single Casks) has been the route to take. As of 2020 with the release of the 100° Proof bottling, drawn from solely ex Oloroso Sherry quarter casks of a mere 125 L volume, this has been changed – in part. In March of 2022, the 100° Proof was joined by an older baby brother, the 90° Proof, which is a 9 year old Smögen matured solely in first fill ex Bourbon barrels of around 200 L volume.

But WHAT is this ”Proof” thing, we can often hear you Smögen lovers exclaim? Well, we are using it to give our two standard bottlings a name other than just their respective age statements of 6 and 9 years old respectively. But it is also an older way of expressing the strength of a spirit, not in percent alcohol by volume, but in ”degrees proof [Sikes]”.

The Sikes scale is British by origin and was used until the 1970’s to express the strength of whisky and other spirits, before the switch over to percent alcohol by volume, likely due to harmonisation with the rest of the world in general and the EEC (now EU) in particular. Now, the Sikes scale being British, it is a bit idiosyncratic – if one is used to the Gay-Lussac alcohol by volume in clear percentage steps, from zero to 100. However, the Sikes scale makes sense from its own perspective.

The relation between the alcohol by volume expressed as a percentage, and as degrees proof [Sikes], is the following. Take your correct percentage alcohol by volume times seven and then divide by four, which will give you the degrees proof [Sikes]; the other way around, take your value X of degrees proof [Sikes], divide by seven and multiply by four, to get your percentage alcohol by volume. Easy maths, once you know how to do it.

But WHAT is the point, we hear you say (again)? Well, the lowest strength allowed for Scotch whisky (and now for all whisky in the EU as well) was first expressed as ”70° Proof” and that happens to be 40 % alcohol by volume (abbreviated to ”abv”). ”75° Proof” is very near 43 % abv and was for a long time the preferred export strength, with a little more whisky and oomph in every bottle. ”80° Proof” is just over 45,7 % abv and is a strength traditionally used for the bottlings of Talisker (which are typically at 45,8 % abv).

Thus, our dear core range bottlings ”90° Proof” and ”100° Proof” respectively clock in at a strength of 51,4 % abv and 57,1 % abv. The former is a concentrated and characterful ”sipping strength” where water can be added but does not necessarily have to be added, while the latter 57,1 % abv is very near a cask strength presentation and thus even more intense, but typically in need of a bit of watering down in order to release the full flavour potential.

(By the way, the American ”Proof” is not the same as the described ”degrees proof [Sikes]”, as it is simply twice the value of the strength in percentage alcohol by volume, i.e. ”100 Proof” in the American system is simply 50 % abv. This just as a side note.)

But then, what is ”cask strength” and what is the point of that? The idea with ”cask strength” if you ask traditionalists like ourselves is simply to express the fact that the whisky has been drawn straight from the cask (-s) and has been bottled without the addition of water to dilute the strength. This means that every single bottling will vary slightly in strength, even when from the exact same type of cask as the prior bottling. This, in turn, complicates plenty of the little things in the life of a distiller, from the strength printed on labels and packaging, to the article number – and even the permissibility – with retailers that shall sell the whisky (most notably in regulated markets such as Sweden where there is a government-operated retail monopoly that does not appreciate variation in bottlings).

The idea behind a cask strength bottling, often a Single Cask bottling as well, is basically to allow for as unchanged a whisky as is possible, short of standing right beside the cask and drawing a cask sample from it. But as already mentioned, this does come with a number of drawbacks as well, from an administrative point of view. And it will cost more.

Using a higher than regular but still specific strength, whether expressed solely in abv or also in degrees proof [Sikes], means a more easily repeatable bottling that can also be diluted to a suitable strength for the purpose and intended market segment of that bottle. And with a lower strength comes a lower price tag per bottle, as there is a little less whisky inside and also less alcohol duty placed on the contents by the government. One aspect of our Smögen 90° Proof is also that quite a number of people have asked us to offer a lower strength bottling, as they do not feel they want to add any water to the whisky. Now, we will always reckon that water and whisky shall be considered each other’s best friends and that one ought to work with water to get the subjective best performance out of every whisky one happens to come across in one’s glass. But we are not pig-headed beyond the reasonable, so we brought the 90° Proof down to it’s still quite juicy strength by adding our very tasty local water prior to bottling. And it has been very well received by consumers and experts alike, which is most pleasing! (Do please check out whiskyfun.com with the entry for the 1st of March 2022 for a review.)