The quality of a new make spirit is crucial to making good whisky. Ian Wisniewski delves deeper into the process
With various single malts offering a broader choice of ages, comparing a 12, 15, 18 or 21 year old from the same distillery shows how the balance between the distillery character, and the influence of oak aging, continually evolves.Deliberating between different ages to see how both elements interact is a great way of ‘deconstructing’ a malt, which also leads back to the beginning of the aging process: the new make spirit and the cask selection.The character of the new make spirit tends to be attributed to the spirit cut, and as the distillate shows varying characteristics at different strengths, there are clear parameters for distillers to work with.However, the spirit cut is only one way of determining the profile of the new make spirit.Other influential factors include whether the heating method is ‘indirect’ (steam heated coils), or ‘direct’ (such as gas or coal); the rate of distillation, the size and shape of the stills, and type of condenser (shell and tube or worms).Moreover, collecting new make spirit is a culmination of the preceding stages of the production process, and distilling low wines with consistent characteristics also depends on a reliable fermentation regime, which in turn relies on mashing and milling.The first distillation in a wash still creates the broad character of the low wines, including the formation of esters. A second distillation in a separate spirit still refines, but also reduces the range of characteristics in the low wines (which includes removing undesirable elements).“It’s one process but we use two distillations, and the level of sulphury compounds can be reduced for example, while the level of cereal notes can also be influenced by distillation,” says Diageo’s Douglas Murray.The second distillation comprises three phases. Foreshots and feints, the initial and final stages of the distillation run, are of an unsuitable quality as they contain various impurities. Consequently, foreshots and feints are collected to be redistilled with the next batch of low wines.In between the end of the foreshots and the beginning of the feints, the spirit cut is collected as new make spirit, with a diverse range of flavours produced during that period.Combining low wines with foreshots and feints, by using a system of ‘balanced’ or ‘phased’ distillation, is standard practice. How it’s done varies among distilleries, with one method being to ‘match up’ consecutive stages of the production process.“Balanced distillation gives you great consistency and allows you to pick up any issues very quickly. At Glenmorangie the contents of one washback provides enough wash to fill four wash stills once, which produces enough low wines to charge each of four spirit stills, which means that we always get the same, consistent strength and quality of spirit,” says Glenmorangie’s Dr Bill Lumsden.Alternatively, using two separate vessels, in the form of a low wines receiver and a feints and foreshots receiver, enables the distiller to maintain consistency by blending a specific volume of low wines, feints and foreshots, within a low wines and feints charger (vessel).As the parameters of the spirit cut are based on alcoholic strength, this incorporates quality control as well as determining the flavour profile. Atypical spirit cut averages out at 70% abv. In terms of the flavour profile, a guideline is that fruity esters are more evident in spirit collected at 72-68% abv, with the spirit cut also influencing the intensity and range of phenolic character.“Where you come on and off spirit gives you the range of flavours. Fruity esters tend to be at the beginning, and cut points are usually set in stone,” says Douglas Murray.Even though various distilleries may take a similar spirit cut, this doesn’t of course mean uniformity in their new make spirit as various other factors also influence the character.The degree of reflux (condensation) is one factor, stemming from the size and shape of the still, with longer necks promoting a greater degree of reflux.This is because heavier, denser, oilier flavour compounds have a higher boiling point than lighter flavour compounds, and as they rise up the still the temperature becomes relatively cooler. This causes them to condense and begin their journey back towards the boil pot (base), whereas lighter flavour compounds proceed to the condenser.Meanwhile, the length of the neck is only one way of increasing the degree of reflux, with accessories such as a boil bowl (a bulbous section between the boil pot and neck) also increasing reflux. The boil bowl can vary from being mildly to acutely convex (the more convex, the more reflux). When vapours carrying heavier flavour compounds expand into this larger, relatively cooler area, they condense and return to the boil pot.“We have a boil bowl on the neck of the spirit still to give a little bit of reflux, and promote some fruity character but also balance, as we were looking for a fuller spirit with a degree of elegance,” says Gordon & MacPhail’s Ewen Mackintosh.Another consideration is the progress of phenolic compounds during distillation. The peating levels quoted by distilleries (in terms of ppm, parts per million phenol) refer to the beginning of the production process.However, phenolic levels reduce during the production process, possibly by up to 40 per cent, depending on factors such as the degree of reflux and the spirit cut.Meanwhile, any changes in peating levels can also affect the spirit cut.“During our initial trials at Benromach with lightly peated malt, the cut point to feints was evident with the build up of pungent wet mash and wet cardboard aromas. However, we quickly realised that lightly peated malt did not deliver the new make character we desired, so we increased the peating levels and reviewed the cut points. We found that the peat smoke character developed later in the distillation process, and so we could take slightly more feints to give us the required peat characteristic - without the same pungent wet mash notes,” says Ewen Mackintosh.The temperature at which new make spirit is collected is another significant factor, as this determines the amount of interaction between the spirit and copper (or ‘the copper conversation’) within the condensers.Interaction with copper is more intense when the spirit is in the vapour phase, and significantly less when it has condensed into liquid. It’s the temperature of the cooling water in the condensers that influences how quickly the vapours condense.“The temperature of the cooling water increases or decreases the amount of copper conversation. If the temperature is hotter there is more conversation and this promotes a lighter spirit, while a colder temperature promotes a richer spirit. The volume and temperature of the cooling water can be adjusted to cater for seasonal factors, like a higher ambient temperature in the summer,” says Douglas Murray.The spirit cut can be less than 20 per cent of the total distillation run, though this depends of course on the house style, and flavour profile required.“In Glenmorangie’s new make spirit I’m looking for beautiful, soft floral and fruity notes, particularly pears and apples. In Ardbeg I’m looking for a pungent, tarry smokiness interwoven with ripe berry fruit, while Glen Moray has a combination of fruit, more berry fruit, spice and maltyness,” says Dr Bill Lumsden.Ewen Mackintosh adds: “Benromach’s new make spirit has a floral note, with a peaty, smoked ham aroma, below which is an estery fruitiness with green apples and ripe bananas.” As a typical spirit cut averages out at around 70% abv, this still means that around 30 per cent of the new make spirit is essentially water, accompanied by various other flavour congeners, such as esters.This raises the question of whether any volatile flavours from the process water survive double distillation, and contribute any character to the new make spirit. Minerals are not volatile, so that rules them out, but even if any flavours do make it through the stills, the influence would be minimal compared to the flavours resulting from the malt, yeast and the effect of distillation. Whether this water can contribute any characteristics or texture is debatable, but it can’t be ruled out.
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