During mashing, hot water is mixed with the ‘grist’, enabling the starches present in the ‘grist’ to be converted into sugars, by the enzymes released during the malting process. The sugars, once soluble, dissolve in the hot water and are extracted as sweet ‘worts’, which are vital for fermenting into alcohol. The sweet ‘wort’ consists of sugars, amino acids, vitamins, acids and minerals and has a pH of 5.4. The ‘wort’ is drained through sieves on the floor of the mash tun, leaving behind the ‘draff’, or spent grain, which provides local farmers with a highly nutritious feed for their cattle. The impressive semi-Lauter mash tun, at Glenfarclas, measures 10 metres wide and with a 16.5 tonne capacity, is one of the largest mash tuns in the industry.
Three waters are used, each hotter than the previous. The first two waters go to be fermented, and the third water is called the ‘sparge’. The ‘sparge’ does not contain enough sugar to produce the required alcohol content during fermentation, so it is saved and becomes the first water of the next batch.
|Temp.||Volume||Draining time||Wort extracted|
|1st Water||64C||64000 litres||3 ½ hrs||58,000|
|2nd Water||78C||28000 litres||1 ¾ hrs||25,000|
|3rd Water||80C||62000 litres||2hrs -|
Time to remove ‘draff’ ½ an hour. (16 tonnes)
Total cycle time for 1 mash, approximately 11 to 12 hours, including cleaning.