When you think about grain distillation, what immediately comes to mind?
For me, it is the stills. I automatically think first about the still shape, knowing that the good old fashioned copper pot glories will have been replaced by tall, slimline stills that rise high into the air. This comes before anything else in my mind’s eye – from the type of grain used (in the UK, generally wheat) to the method of distillation. It is an image of those still shapes that bursts forth.
And while I have read and learned much about whisky production, it was not until I headed to the Girvan distillery on the Aryshire coast in late 2013 that I really gained an appreciation for all the major differences that there are between grain and malt distilleries.
In fact, grain distillation is much more complicated than I grasped before my visit and has changed the way I will speak about it for the future – a handy fact since Girvan itself has just launched as a single grain brand (The Girvan Patent Still) and the idea of single grain whisky is becoming more popular (led, partly, to a large output by independent bottlers).
As background, Girvan was founded in 1963 by the William Grant & Sons operation (the family company which also owns The Balvenie, Glenfiddich, Kininvie, Monkey Shoulder, Tullamore Dew and the branding for US craft distiller Hudson). Set up by Charles Gordon as a way to provide the grain component of Grant’s Standfast blend – and due to a falling out with what was DCU (now Diageo) over TV advertising – it was a thoroughly modern distillery at launch.
When the group I was up with arrived on the cold, weather temperamental November afternoon it was immediately clear that the main thing to stand out about a grain distillery is its sheer size. Imagine in your mind a traditional malt distillery, all twee with lots of cute stone buildings, pagoda roofs and pebbled walkways. Now erase that image, multiply everything in size by about 10 and look up – way up – for everything is big and bold.
Despite the size, there is a definite beauty to it all – perhaps well accentuated the afternoon of my visit by the black clouds threatening oncoming sideways rain but through which the winter sun was attempting to stick out of, giving everything an intensity that was illuminating.
But back to the size of everything. Grain distilleries are expansive. Girvan’s annual capacity is currently 103 million litres per annum and that’s running at 50 weeks a year, making it the UK’s largest grain distillery. If there wasn’t a need for a two-week shut down, that could be increased to 117 million. To give you an idea, the big boys of the malt world (think Glenfiddich or The Glenlivet) produce around 12 million litres and 10.5 million litres respectively.
We started our tour inside what would typically be the mill room. For the Girvan process, the team uses a mix of 90% wheat to 10% malted barley (HDU malt which increases the yield lost by the less well-performing wheat) in the mashbill.
In order to get the wheat to its correct usage size, the distillery has a Tietjen hammer mill (rather than a roller mill) which smashes the wheat through a series of screens to give different sizes of grist.
A main differential at this stage is the fact that when wheat is used for the process, the grist is not just run through a mashtun with different temperatures of water to extract the sugars, but is actually cooked. In this case, this is done using pressure cookers, injected with direct steam of around 135 degrees centigrade.
Once it has cooled down to 90 degrees, the milled HDU malt wort (which is processed separately to the wheat) is mixed in on the way to the fermenting vessel (the grain distillery name for a washback). And this is where we get back to the sheer size aspect of things. The fermenting vessels are HUGE – on average, 450,000 litres. We headed outside into the crisp winter air to see these babies puffing away, making for an incredibly beautiful sight. They are gas fired and create huge amounts of steam due to being outside (around 54 tonnes per hour!)
The wash comes out at an average of 10% ABV, so it is higher in alcohol to begin with compared to that in malt whisky production. The team is currently doing around 265 batches per week, getting around 80,000 litres of wash per hour. Again – an incredibly large amount.
Next up, we headed into the monitoring room to watch the team overseeing the stills. While everything is done on computer, it is still an extremely technical job, with more components to look after and numbers to record than one has with a traditional pot still set up.
Girvan uses three stills – one (called #1) is an original Coffey still from 1963, which does about 17% of output. The other two (#4 & #5) cover off the rest and use a multipressure vacuum distillation method. This method was fully implemented in 1992, making it the first grain distillery to use a multipressure method. Because of this aspect, temperatures, pressure and liquid movement has to be rigorously kept track of to ensure the operation is running smoothly.
To begin the process using the multipressure method, the incoming wash is heated to 80 degrees centigrade – there is a very small window, however, of how much it can heat up to (never more than 86 degrees centigrade) because otherwise the proteins can burn. For Girvan, the team is trying to create a fruity spirit, and an additional factor of too much heat would mean losing those fruity esters and making the process less energy efficient. The wash runs through first the analyser (which is under the vacuum pressure) and then the rectifier (which is in a state of over-pressure). The rectifier helps to take off what are called heavy uncondensable particles, such as fusel oils, which are actually recycled by being redistilled to remove any alcohols and sold onto the cosmetics industry. It comes off the still around 94% ABV.
In order to gain a better knowledge of just how big the stills were, we all headed outside and over to them – something I was not expecting as it is rare to be quite so up close and personal to things at a distillery. Rising 95 metres into the air, the stills are monstrous and climbing up and up the steps (in the spitting rain, I might add) meant holding onto my nerves (I’m not a massive fan of heights).
But it was incredible. When you get up to the second or third level, you can see out to the roaring sea and across the dozens of warehouses spread across the nearby fields. The distillery fills around 2.5-3k casks per day of spirit for whisky, most of which (around two-thirds) go to external clients such as Diageo and Chivas for their blending needs. While the Girvan Patent Still grain whisky is, of course, hitting the market I’ve been told there is unlikely to be a decrease in the amount sent to partners due to the sheer size of the blended whisky industry.
When finally we all reached the pinacle, it was just as the sideways rain start to pour down. Even so, it was an extremely memorable sight – and, luckily, I had eight people around to convince me that I had to go back down the ladder (otherwise, I may have stayed stuck on the upper platform for hours).
What surprised me most about Girvan was certainly its size, but equally the fact that it is not such a simple process as I first envisioned. I’d always thought of grain distillation a bit as feeding wash in and letting it come out the other end in a continuous fashion. Which, technically, it is but with many additional factors thrown in. The care and expertise the teams put in matches that of a malt distillery and has made me reevaluate the skill it takes to create, something I shall keep in mind the next time I have a single grain whisky.
After our outdoor adventure, we headed into the warmth where we sampled a range of whiskies – all of which I’ll review in another post coming out Friday.
In conclusion, not only did I discover grain distillation to be complex and fascinating, but I gained a new respect for it. Single grain whisky will no doubt be on the rise as more companies look to expand options for the ever-growing army of global whisky lovers and I look forward to seeing just how companies respond the world over.