Those that have been to a distillery or even seen pictures from one, have most likely also noticed the odd shapes and sizes of many of the stills out there.
And, as with alot of other factors (malt specs, fermentation, casks etc.) the shape of the stills also add to the character of the final spirit.
5 things usually contributes to the character (in no particular order). That's the fill level of the stills, the time of the spirit run (cut), the heating of the stills, the shape of the stills and condensing method. Let me just run these past you:
The fill level is how much wash or low wines you put into your stills and the lesser you pump into the still before distillation the more copper contact it will have during the process i.e. resulting in a lighter style of spirit.
Next is the spirit run... the heart of the run or the middle cut. Some has a narrow cut, which only lets the purest of the spirit go through to become whisky after 3 years time. Macallan is one such distillery with a middle cut of only 16% - the rest is re-distilled. Others have a wider cut and this is why sometimes can get whisky that's a little 'rough' or 'hot'.
Then there's the heating of the stills. This is really as much a religion as is stainless steel vs. wooden washbacks. Most distilleries today have steam coils inside the stills for heating and the reason for that is that it gives a more even heating of the liquid inside, being either wash or low wines. I'm sure this is great for consistency and this is what big producers want in their product...
Only a few distilleries today still use direct firing of their stills, among them Springbank in Campbeltown and a very notable Speyside distillery -
Glenfarclas. At Glenfarclas they actually did trial runs with steam coils in a couple of still some years back, but reverted to direct firing as they concluded that the spirit coming off these still wasn't quite Glenfarclas. They even did lab tests that confirmed this... So does this have an effect? I'd say yes... as sugars in the sweet wash burns up and stick a bit, maybe... and the low wines gets an uneven heat dispersal perhaps affecting what comes within the spirit cut, maybe - as these are usually timed on a clock.
Then there's the shape of the stills and condensing method. You know they come in almost all shapes and sizes... and this certainly does matter. Small squat stills gives a more heavy and oliy spirit as does still with a small angle° on the neck of the still. This is because the vapours flowing over the neck of the still starts to condense there already, carrying over the heavier flavur compounds when they reach the neck. Macallan again is a good example of small squat stills. The opposite is i.e Glenmorangie that, with the tallest stills in Scotland (
5.13m - picture here), makes a very light spirit, allowing for more reflux (back flow into the still) of vapors - getting it heated up again and with that, usually making it lighter, before it condenses again.
All of the vapours doesn't condense back into liquid form after crossing over the neck of the still, also often referred to as the 'swan's neck'. Some of this happens in the condensers. There's usually two distinct forms of condensers, the widely used tube condensers (
pic inside one here). The other one is a worm tub... there usually to forms or rather shapes of worm tubs. A worm tub is a length of copper piping submerged in cooling water, condensing and cooling the vapour/spirit as it passes through the piping. Noticeable distilleries that uses traditional round wormtubs for colling/condensing are Mortlach and Dalwhinnie and
the square kind is used at Balmenach and Craigellachie.
Distilling is fun, isn't it? :) ... and I'm sure there's more takes on what contributes to the spirit character than what I've mentioned here... If you have other takes on it, please use the comments field below
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| Bunnahabhain Stills, May 6th 2011 © The Malt Desk |
Bunnahabhain 1979 28yo (31.10.1979/22.04.2008) 46%, ex-bourbon barrel#18831, 234 bottles, Single Malts of Scotland
Colour is full straw
Nose:
Sweet on vanilla and candied sweets, almost to the point of floral. Malt lurking in the background. Also fresh pancakes. Both orange soda and orange marmelade in there as is sweet apple.
Taste:
That malty Bunna I love so much shows right away. Then it gets tropical sweet for a moment on pineapple heading towards apple and pear, before settling on a lovely clean malt taste. Finish provides you with some spicyness, mainly in the form of pepper and ginger. Lovely fresh and crisp after 28 years - never getting overly sweet.
Would have loved to try this at full strength whatever that might have been, before being watered down to 46%.
89/100!
