Mashing Islay Barley

IN The Distillery 19th July 2016/by Jane Carswell

We are now Mashing Islay Barley in order to distill some of the unpeated grain grown on Islay last summer.

Mashmen Graham Hayes, Graham Kirk, and Robert McEachern are watching over the milling, soaking, and careful draining of the grist – processes all designed to maximise the extraction of its natural sugars – before initiating fermentation through in the tun room. It’s a delicate balance of volumes and timing, requiring patience and relying on the mashman’s knowledge and experience; the quantity of water entering the mashtun is measured in inches (186 litres an inch) and the barley can behave differently with each batch.

The creation of the wash, a sort of beer or proto-whisky, is continually monitored through the liberal use of thermometers, hydrometers, and dipsticks, and calls for the mechanics of pumps, valves, taps and heat exchangers but famously not computers.

The dry grain absorbs a proportion of the ‘first water’, so the mashman must correctly judge how much to add into the mashtun in the ‘second water’ so as to achieve the anticipated combined drainage of 35,000 litres at the best concentration of sugars. Graham Kirk finds, ‘This barley holds onto a lot of water.’ The mashmen agree that the grain is bulky, as do the hauliers who struggle to fit the regular 28 tonne delivery from the maltsters into the trucks.

The only real proof of whether everything has gone to plan is, primarily, whether the correct space is left above the liquid after it has been mixed with yeast in each of the individually calibrated 6m tall washbacks of oregon pine. The washback dipstick is in cm; the target on washback 2 is a watermark at 154. Of course, if the liquid heats up its volume changes, so keeping the temperature low as the washback is filling is a particular challenge at this time of year.

Ultimately, the results of the mashman’s endeavour is shown in the alcohol yields at distillation. And in the drinking of what will become Bruichladdich Islay Barley 2016.