MASHING
The grist is pumped from the mill straight into the mash tun, a container equipped with a stirrer and a perforated bottom, like a sieve. The wet grist is then spread in an even layer on the sieve plates. Following a careful blending for 30 minutes, the sparging begins. The solids are separated from the now sugary water, also known as wort. The wort is strained off and cooled prior to being pumped into the washback where the journey towards an alcoholic mash begins.
The conversion of the starch in the malt into sugars is done by the natural enzymes present in the malt. Before the wort is pumped into the washback it is pumped back into the mash tun. This is done so that any solids that may have passed through the sieve plates end up on top of the mash bed, and only the clear, sweet wort passes through the sieve plates.
As the wort is pumped to the washback, it passes a heat exchanger, which cools it from 60°C to around 20°C. The water used for cooling is now warm and is then heated a few more degrees and used for sparging.
Normally, a distillery will add water three times to sparge the sugary wort. We add sparge water seven times, in order to extract all the aromas and sugars from the malt, without compromising on quality. 1350 kilos of malt will yield, once the mashing is completed, 5400 liters of wort.
Once all the wort is drained out of the mash tun, only the solids –called 'draff'- remain. This draff is collected by a farmer and used for animal fodder.
Our mash tun is also manufactured by the German company GEA. It is equipped with the latest technology, and is monitored by an advanced computer programme. Based on the characteristics of the mash bed, it sets the speed and height of the stirrer as well as the flow of the wort, in order to optimize the process. At the end of each run, it automatically expels the draff and initiates a small washing cycle to keep the sieve plates clean for the next batch. From start to finish, each batch takes about six hours.