SCOTCH WHISKY

All Scotch (and Irish) whisk(e)y is produced by first grinding the particular cereal grain(s) to a coarse flour and then sweeping this in hot water in a mash tun. The resultant liquid, called wort, is then cooled to between 22 and 24 degrees centigrade and run back into a wash back. Yeast is then added. Once the yeast has been fermented out, a strong ale called pot ale remains, which is about 9% alcohol by volume. This pot ale is then distilled by heating it in cooper stills, either in a continuous still, called a Coffey still, for Grain whisky or twice in the case of Malt whisky using a pair or a Pot stills. Thre stills are used for Irish whiskey and the Scottish malts Auchentoshan, Benrinnes and Rosebank, these all being tripled distilled. Pot stills are usually onion-shaped, with tall, tapering swan necks designed to held the alcohols condense, after which they are collected, cooled and put into casks.

The whisky year

Many distilleries began their lives on farms. The distilling season began after the harvest and continued until late April. Until modern times this cycle was followed by all distilleries and even now there is a 'silent season', usually in August when many distilleries are closed.

The malting process

The process of malting converts the plain barley grain into malted barley and by so doing greatly changes its chemical makeup. The barley first soaked for between 48 and 72 hours in tanks or 'steeps' and allowed to germinate. Germination releases heat which has to be controlled in order to keep the temperature around 16 deg C and avoid the barley killing itself from its own generated heat. Traditionally the malting barley was drained and spread out over a large floor then turned regularly by hand with rakes or shovels. This was repetitious and arduous work, leading sometimes to a repetitive-strain called 'monkey shoulder'.

The Malt Kiln

The fully germinated malt is next transferred to the kiln for drying on a mesh over a fire containing a certain amount of peat, thus contributing to the peaty taste evident in many malt whiskies. Traditional malt kilns draw the hot air from the peat furnace through the malt by way of a chimney effect generated by characteristic steep roofs and pagoda heads of many Scottish distilleries. The pagoda roof was introduced around the 1890s as it offered an improved air draught, fanning the peat furnace to core temperatures which can reach between 800 and 1200 deg C. In most cases, where most distilleries buy in their malt they have mostly lost their function other than a piece of visual identity. The malt is dried and roasted in the peat reek at 60 deg C for two days and then ready for the next stage.

Dressing

The malt contains much detritus or 'combings', principally rootlets. These are removed and used as cattle food. The malt is then coarsley ground and becomes known as 'malt grist'.

Mashing and brewing

The malt grist is fed into the 'mash tun' where it is combined with a carefully measured quantity of hot water. This completes the conversion of dextrin into maltose and produces a fermentable solution of malt sugars called 'wort' or 'worts'. Again, after several washings to draw out the malt, the solid residue or 'draff' is removed and sold as cattle food. The worts are held in a receiver called an 'underback'. This must be cooled to prevent unwanted decomposition of the maltose and to allow yeast to be introduced. The cooled worts are injected with yeast and the fermented in a further tank or tanks called 'washbacks'. Thirty-six hours or thereabouts ofsometimes violent fermentation produces a weakly alcoholic (10 degrees or thereabouts) clear liquid called 'wash', which will now be distilled.