What exactly gives each different Scotch Malt its distinctive aroma and taste is shrouded in mystery, indeed the process has been described as a “wild, weird alchemy”.
This is the first stage in the process. The barley is harvested in the field and then taken to the maltings. Here it is steeped in water and then spread out on malting floors, (or in the more modern industrial environment, in large drums), to germinate. It is turned regularly to prevent the build up of heat.
After about a week of germination the barley goes to the kiln for drying. This halts the germination. Peat is often added to the fire to impart flavour to the barley from the smoke, this is a common process on the island of Islay.
The dried malt is ground into a coarse flour or grist, which is mixed with hot water in a large vessel known as the mash tun.
Soft pure Scottish water is used in this part of the process and this contributes greatly to the quality of the final product. The mash is stirred in the mash tun and this converts the starch in the barley into a sugary liquid called wort. The spent grains, called the draff, are processed into cattle feed.
The wort is cooled and pumped into washbacks, where yeast is added and fermentation begins. The living yeast feeds on the sugars, producing crude alcohol which is similar in aroma and taste to sour beer. Small quantities of other compounds known as congeners, which contribute to the flavour of the whisky are also produced. The alcohol combined with the congeners is known as wash. After about 2 days the fermentation dies down and the wash contains 6-8% alcohol by volume.
This is the part of the process where the magic starts. Each distillery has a different shape and size of pot still and this is crucial to the individual character of each whisky. The pot stills are made of copper and are a distinctive swan-necked shape. This is a batch distillation process.
Malt whisky is distilled twice, the first distillation taking place in a larger wash still, and the second in a slightly smaller low-wines or spirit still. The Stills are heated to just below the boiling point of water and the alcohol and other compounds vaporize and pass over the neck of the still into either a condenser or a worm, a large copper coil immersed in cold running water, where the vapour is condensed into a liquid.
The distillate from the wash still, known as low wines, goes to the spirit still for the second distillation. The stillman exercises much more control in the second distillation as only the “heart of the run”, or “middle cut”, of the spirit flow will be collected as new spirit. This takes place as the spirit flows through a spirit safe, where the stillman can observe, assess and measure it. The first runnings from the still (foreshots) and tails (feints) are returned for redistillation with the next batch of low wines. The “heart of the run” is collected by the stillman, only when he is personally satisfied that it has reached a high enough standard.
THE MAKING OF GRAIN WHISKY
Grain whisky is usually made from a combination of malted barley and either maize or wheat. The starch in the non-malted cereals is released by pre-cooking and converted into fermentable sugars. The mashing and fermentation processes are similar to those used for malt whisky.
The wash is distilled in a Coffey or Patent Still, named after its inventor Aeneas Coffey. It has two tall columns – a rectifier and an analyser. Cold wash is pumped in at the top of the rectifier and meets steam. The alcohol is cooled, condenses and flows away as Scotch grain spirit. The distilled grain spirit is lighter in character and aroma than most malt whiskies and therefore requires rather less time to mature. The vast majority of matured grain whisky is used for blending.
Grain whisky is produced in a continuous process as distinct from the batch distillation for Malt Whisky.
THE MATURATION PROCESS
Once distilled the whisky (both grain and malt) is run into casks for the maturation process. The quality of the casks is very important as the new spirit will gain character, flavour and colour from the wood and this will subtly enhance the liquids characteristics. Many casks will previously have been used to store other spirits such as fino or amontillado sherries or bourbon.
By legal definition, Scotch Whisky must be distilled in Scotland and left to mature there for a minimum of 3 years before it can be called “Scotch Whisky”. The majority of Scotch Whisky matures for much longer – from five to fifteen, twenty, even twenty five years or longer. This is a vital part of the process and it’s this prolonged period, during which the microclimate around each distillery works its magic on the marriage of the porous wood and the whisky, where the individual and distinctive character of each whisky is created.
Around 2% of the whisky in each cask evaporates annually and is lost to the heavens. This is known as the “angels’ share” and it means that the air around the distilleries is nice and healthy!
It should also be remembered that, unlike wine, whisky does not mature further once it is in the bottle. So if someone gives you a nice gift of a 25 year old malt you’re better drinking it than leaving it sitting in your drinks cabinet!
THE ART OF BLENDING
Whilst Single Malts are becoming increasingly popular around the world, due in part to the consumer becoming more educated, over 90% of Scotch whisky sold worldwide is in blended form. Blending was invented in 1853 by Andrew Usher and at the dawn of the 20th Century blended whisky took the world by storm.
The Master Blender is entrusted with the complex task of creating a marriage of Single Malt and Single Grain whiskies to make a blended whisky.
The Art of Blending can be described in many different ways, from painting a picture or hosting a dinner party to conducting an orchestra. Essentially what the Blender is doing is bringing together lots of different individual component parts and combining them in a harmonious manner.
The technique the Blender uses is known as “nosing”. He does this in a tulip shaped glass which is designed to maximise the aroma of the whiskies. He then brings together up to 40 or 50 different whiskies – from the numerous Highland and Speyside malts to the strongly flavoured and peaty Island malts, and the softer and lighter Lowland malts. A blend of a range of malt whiskies, with no grain whisky included, is known as a vatted malt. However, these vatted malts are usually combined with grain whiskies – usually 60-80% grain whiskies to 20-40% malt whiskies, and are then left to ‘marry’ in casks for a further 6 to 8 months to make blended whisky.