Hello, Roberto here, giving you a little insight into a day in the life distilling at Nc’nean as a Distillery Operator.
The stillhouse is the heart of the whisky distillery. It holds the beautiful copper pot stills that turn our amber, fermented wash into the crystal-clear spirit that becomes our single malt whisky. Crucial as they are, no alcohol is produced in the stills. Through distillation, we simply concentrate the alcohol we created during fermentation. So how does it work? What decisions do we make as distillers to ensure our whisky is consistent, delicious, and, well, consistently delicious! Let’s follow a day in the life of a Nc’nean distiller and reveal the secrets of the intriguing art of distillation.
MORNING:
The distiller’s day starts before the rest of the team. Our biomass boiler needs to spring into action after its nightly slumber. A flick of a switch begins an automated process which feeds wood chip from a store into the furnace, and with a little encouragement in the form of a small box of kindling, the fire begins to roar, heating up a tank of water to produce steam.
After a coffee and a chat, we’re up to 5.5 bar of steam pressure and can begin charging the stills. We’ll pump the 5000 litres of ’wash’ (the fermented liquid produced from mashing) into the Wash Still, and the 3500 litres of ’low wines and feints’ (we’ll get into that) into the Spirit Still. Inside each still is a huge coil of stainless steel through which our steam will pass. Once the liquid covers these coils, we close the still door and crank up the steam.
As the steam heats the liquid in the stills, vapour rises to the top and flows down the angled tube called a lyne arm to the condensers. This is where our hot vapour is cooled and becomes liquid once again. As alcohol vaporises more readily than water, our cooled distillate is stronger than the liquid it arose from. This, in a nutshell, is distillation.
Our condensers use around 120 litres of water per minute for cooling, and there’s two of them. Multiply that by the minutes in a day, five days a week, 50 weeks per year, and you’ve got.....well, it’s a lot of water! Here, Nc’nean has a neat trick for reducing water use in the form of a large pond. Cold water feeds into the pond from the hills and is pumped through our condensers. Warm water comes out the other end and goes back into the pond where it cools down again and the cycle continues.
Back to the stills. The Wash Still doesn’t need much attention. For the first hour we keep an eye on the sight-glass because the liquid itself starts to rise, like a pan of pasta boiling over. We can’t let the wash rise up and over the top of the still, so we adjust the steam down. At about 95°C, liquid begins to run into the ‘spirit safe’ (the copper cabinet of bowls and hydrometers you’ll find in every whisky distillery).
The 8% ABV wash we started with has become ‘Low Wines’, a distillate of about 25% ABV. The still will bubble away for the rest of the day, with the output collected in the ‘Low Wines & Feints’ tank. The Spirit Still, being the smaller of the two, actually heats up faster and requires a bit more attention than the Wash Still.
Once at 85°C, liquid will start to trickle into the spirit safe. This first run, known as the ‘foreshots’ or ‘heads’, will be cloudy and contains unwanted compounds such as acetone and methanol. Unwanted, but not wasted - we’ll direct this into the Low Wines & Feints tank too. Once the cloudy run has passed, we set a timer for ten minutes and turn down the steam so the temperature holds at around 86°C.
The timer beeps and we test the strength of the liquid with a hydrometer – it should be 75% ABV, our first ‘cut point’. We’ll now direct the liquid into the spirit receiving vat with the turn of a handle. This is the ‘hearts’, the part of the spirit run that will go into cask to become whisky. We keep the steam low – a gentle flow preserves the bright, fruity character of our spirit.
LUNCHTIME:
After a couple of hours, we’ll test the strength of the spirit again. The ABV of our distillate reduces throughout distillation, leaving an ever-weaker solution in the still. At 69.5% ABV, we’ll make our second cut, directing the liquid back to the Low Wines & Feints tank. This is the ‘feints’ or ‘tails’. Again, it’s not wasted, but we don’t want to put it into cask as it is. The low wines, foreshots and feints will all be pumped into the spirit still tomorrow morning, ready to do it all over again! The heart of our spirit, between 75% and 69.5% ABV, is all we’ll put to cask - that’s around two-and-a-half hours of spirit run per day. It’s deliciously light, very fruity and is chosen because it retains freshness and develops complexity and intensity with a relatively short maturation time. For six weeks per year, we shift these cut points to 72%-66% ABV, giving us a weightier spirit, more suited to long maturation (so long we haven’t bottled any yet!).
AFTERNOON:
Now we’ll leave the stills to do their thing and it’s out in the tractor (we’re all tractor drivers here at Nc’nean, even us townies!) The bio-mass boiler has an insatiable appetite for wood chip, the pot-ale needs spreading on the local fields, and casks need filling.
At the end of the day we’ll return to check the strengths again. Once the still contents reach 1% ABV, there is little to be gained by distilling further – lots of energy used for very little alcohol – so we’ll switch off the steam and pump the remains out to the pot-ale tank, ready to be disposed of tomorrow. Then, a bit of cleaning here and there and the day is done. Time for a dram!
