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Let’s talk about Grain Distilleries: Girvan Distillery

Grain whisky distilleries don’t get as much coverage and I think it’s quite a shame. There are many exciting innovations that may seem foreign to a traditional pot still Single Malt distillery. Today, I am starting with Girvan!

The grain distillery is situated near the coastal town of Girvan, which it is named after. William Grant & Sons (WGS) owns the Girvan distillery. WGS also own Glenfiddich, Balvenie, Kininvie, Alisa Bay and Hendricks in Scotland. Girvan distillery is in a site just over 1.5 kmsq that also contains Ailsa Bay distillery, Hendrick’s gin distillery, company offices, a cooperage and more than 40 warehouses.

How did Girvan start?

Before Girvan distillery started, the Distillers Company Limited (DCL) was supplying WGS with grain whisky for their Grant’s Blended Scotch. But then, WGS aired an advertisement on the television for their Grant’s Standfast Blended scotch, shown below. DCL saw that move as direct competition and threaten to cut off their supply. Given that this is the mid 20th century, where blends reign supreme. Losing their supply of grain whisky will affect their ability to continue producing Grant’s Blended Scotch.

Grants Stand Fast Whisky. Source

After that dispute, WGS wanted their own supply of grain whisky and they decided to build the Girvan distillery. Within nine months, the construction was complete and the distillery was functional! Charles Gordon, who oversaw the construction of Girvan distillery, had the first spirit distillation run on Christmas day of 1963. This choice of the day pays homage to Charles Gordon’s great grandfather, William Grant and Glenfiddich distillery, which also first ran their stills on Christmas day as well. Today, the distillery operates a continuous process 24/7 and also has a capacity of over 100 million litres of pure alcohol per annum! How does this distillery achieve this feat? Let’s take a look at the production to find out!

Malting and Mashing

Girvan uses approximately 10% Malted Barley and 90% Wheat in the grain bill for several reasons:
1) Scotch Single Grain must have some amount of Malted Barley in it as dictated by the SWA.
2) The enzymes in malted barley to help break down starch into fermentable sugars.
3) Wheat is inexpensive.

Like many grain distilleries, the wheat Girvan distillery uses for grain whisky distillation is unmalted, which saves money and time as there is no malting process for the wheat. The malted barley and wheat go through separate mills and mashes with hot water separately as well. The slurry is then mixed together before the fermentation.

Fermentation

Unlike a traditional pot still distillery, the mash does not go through filtration into a liquid wort before fermentation! Instead, these grain solids, that would have normally been “draff”, mix with the sugary liquid mixture to form a porridge-like slurry.

This mash slurry then ferments in one of 29 fermentation vessels for around 60 hours. After two and a half days, the “wash” slurry is around 10-11% abv. The slurry then enters the column still.

The stills at Girvan

Girvan has a handful of column stills but some of them have been decommissioned. No. 1 Apps (Apps short for Apparatus) was the first Coffey still that was running since the distillery started in 1963, until its decommissioning in 2016. No. 2 Apps and No. 3 Apps are also decommissioned.

Column Stills at Girvan Distillery. Source

The currently running stills are No. 4 Apps and No. 5 Apps, which uses a Multipressure System (MPS) that the distillery started installing in 1992. This MPS technology allows for vacuum distillation, which means the column still is operating under atmospheric pressure. In other words, this lower pressure distillation means that ethanol will boil at a lower temperature, a bit like how water boils below 100°C when one is up high in the mountains where the air pressure is lower. You can see a video about that here!
This MPS vacuum distillation help saves energy as well, as the column operates at a lower temperature!

Distillation

Simplified Diagram of distillation at Girvan. Source

After the fermentation, the slurry enters through the top of the column, as shown in the diagram above. At the bottom of the analyser section, the column is heated by direct steam injection. That is to say, the hot steam interacts and heats the slurry directly, with solids and water flowing to the bottom whilst the alcohol vapours and congeners (flavour compounds) rise to the rectifying section. This separates the grain solids from the alcohol and congeners. To help visualise this process, I recommend the video below from Girvan distillery!

The distillers take precaution to ensure the wash entering the still is approximately 80°C and below 86°C. This tight control on the temperature is due to the compromise of wanting a higher temperature for faster distillation and wanting a temperature below 86°C so that the congeners and grain solids will not burn. This not only ensures a fruiter grain spirit as the congeners do not burn but also ensures process safety!

In the rectifying section, the fusel oils are also taken away, which will
1) Allow the final distillate to be softer.
2) Prevent a build-up of fusel oils in the column to ensure smooth continuous operation
3) Be sold to the cosmetics industry and reduce the waste Girvan produces

The stainless steel columns also have sacrificial copper to help purify the distillate similar to a copper pot still in a single malt distillery. However, the sacrificial copper unit needs to be replaced like a shaving cartridge. Below is a photo of sacrificial copper packings from Chris Burgess, Distilleries Process Leader at WGS.

Sacrificial Copper Packings. Source

Not just a Grain Distillery, but a Green Distillery

Girvan is a prime example of a Green Distillery. Remember all the grain solids that fall to the bottom of the rectifying section? All that biological by-product are used to make biogas, which can then help power the distillery itself. In fact, this process is so efficient that it not only meets the 4.8MW power demand of the distillery but sends the excess 2MW of power back to the power grid to power residential households!! That is truly amazing!

Girvan distillery deserves more attention

Now here’s my biggest issue with Girvan Distillery: No Visitors Centre! >:(
This remarkable eco-friendly distillery which was the first to implement the MPS system back in 1992, truly deserves praise and attention. Furthermore, planning a steady-state continuous distillation requires careful planning to make sure heat and materials (like grain solids and fusel oils) do not accumulate, and everything runs smoothly. This ensures product quality, efficiency and a low carbon footprint!
Now hopefully they release more Girvan, maybe a quarter cask or a sherried octave! <3

Sources:

Girvan Official Website.
Scotch Whisky Cereals Technical Note – 3rd Edition (Scotch Whisky Association)
Girvan Distillery decommissions No.1 Apps (Spirits Business)
Sustainable Planet: Refine Fuel Consumption by Paul Studebaker.
Sustainable Energy using Anaerobic Digestion of By-Products (University of Strathclyde).
How to make greener whisky? Power Grid Internation.
Whiskypedia: Girvan.
Not Backing Down By Gavin Smith (Whisky Magazine).
Tom’s Whisky Reviews – Girvan Distillery Tour.
Distillery Stories: The Girvan Distillery by Greg (Great Drams).
Distillery Visit: Girvan (Whisky for Everyone).
Girvan Distillery (Miss Whisky).

Nantou Distillery (Omar whisky) visit!

Nantou distillery has been making Omar, a Taiwanese whisky, since 2008. The distillery tours there are quite like those of Scotland. The tour guide makes the experience more intimate, more personalised and less commercial. Nantou distillery’s willingness to experiment makes them unique, especially to whisky geeks like myself! I know many of you are more interested in the whisky; so I will leave the technical production details to later in the article!

Omar Whisky

Nantou winery makes different fruit wines and liqueurs which can be used to season casks for unique cask finishes. Omar whisky has released whisky finished in casks of Lychee Liqueur, Plum liqueur, Black-Queen Wine and Orange liqueur.

Batch 4 Lychee Liqueur Cask Finish

This Lychee liqueur finish has a balanced Lychee note that does not overpower the whisky. I enjoyed the tropical fruit notes of pineapple and mango alongside notes of pear drops!

Batch 1 Orange Liqueur Cask Finish

This dram is for the orange lover with notes of orange puree, orange zest, and orange flower water alongside some lovely notes of vanilla and honey from its prior maturation.

I am particularly fond of their bourbon cask strength, both peated and unpeated! But do not fret about the age statements. Due to a higher average temperature, maturation speeds are a lot faster than Scotland. A 3-year-old whisky at Nantou would taste similar to an 8 to 12-year-old whisky matured in Scotland. The 8-year-old cask strength is a special release; it feels like a 15-20-year-old scotch.

Omar 8yo 2009 Cask Strength

This 8yo is very soft and demure, giving notes of old oak, vanilla, pears and mandarin oranges!

Omar 3yo 2014 Peated Cask Strength

The 3-year-old peated cask strength displayed a high calibre of maturation, with the right balance of peat smoke. Water will draw out more smoke for people who love that note! This delicious yet affordable single cask would be good smoky daily dram!

Omar 10yo 2008 PX Sherry Cask

For sherry bomb lovers, this is an absolute sherry nuke or WMD! This is the result of 8 years in sherry hogshead before finishing in a PX cask for two years. This dram holds notes of Christmas cake, cinnamon, chocolate, plums and dried fruit!

Barley

TTL buys barley in bulk from multiple maltsters. Most of the unpeated barley is from maltsters in England, while most of the peated barley at 35ppm is from maltsters based in Scotland. The moisture content is also similar to specifications required in Scottish distilleries, around 4%.

Milling & Mashing

The barley is milled into grist with the standard ratio of 70% grist, 20% barley husk and 10% flour. Distilleries maintain specific ratios to assist in the filtration of wort and to prevent choking in the pipes. The grist is sent to a German semi-lauter mash tun with a charge of 120000L. Hot water is added three times; the first and second streams form the wort. The third stream, called the sparge, picks up the remaining sugars, but it is low in sugar. The sparge is not mixed with the first 2 streams, but to maximise sugar recovery. This is done by reusing the sparge for the first stream to be added to the next batch of grist.

Fermentation

The wort goes into one of the stainless steel washbacks to undergo fermentation, turning it into a strong beer called wash. In this stage, the yeast will start eating the sugar in the wort and produce carbon dioxide and alcohol. For Omar whisky, this fermentation process takes an average of 72 hours using French distiller’s yeast. This is slightly longer than the 48 hours of fermentation in most modern Scottish distilleries. The wash from Omar is around 7-8% alcohol by volume (abv).

Distillation

Pot stills

The wash goes into one of 2 wash stills to be distilled into low wines. This distillation removes the barley solids leaving mostly ethanol, water and aromatic compounds. The low wines are pipped into the spirit still for its second distillation to reduce water content. Nantou Distillery currently has 2 Wash Stills and 2 Spirit Stills. One spirit still is different, as it, strangely enough, has a window. The stills are of varying sizes, one at 7000L, two at 5000L and the last one at 2000L.

Cut of the Heart

There are three components in the spirit still distillate. The head comes first at a high abv, followed by the heart, which is what goes into the barrels, and lastly comes the tail which has a lower abv. The cut of the heart affects the new make spirit and how the whisky tastes. If the cut starts at a higher abv, the new make spirit gets lighter, fruity notes, but also more undesirable flavours from the heads. If the cut ends too low, it gets heavier flavours but risk lowering the final abv.

The master distiller decides how to balance these two points. For Omar, the cut of the heart is somewhere between 73% and 64%. This means that the stillmen sends distillate above 73% (heads) and below 64% (tails) into a tank to be redistilled. The heart that is within the range will go into barrels for maturation. Due to Taiwan’s legislation, Nantou Distillery reduces the strength of their new make spirit to just below 60% abv before filling in casks.

Maturation

Cask Management

Nantou distillery receives the sherry and bourbon casks whole so that the cask maintains its inherent quality. Nantou distillery uses ex-bourbon casks up to 3 times. As for Sherry casks, there is no fixed numerical limit. Craftsmen will keep utilising the sherry cask until they deem it to be too exhausted to provide flavour. According to the tour guide, the sherry casks usually provides stronger flavours in Nantou’s climate, therefore using refill would give a more balanced dram.

 

3rd and 4th fill Bourbon casks are usually used for seasoning with wines or liqueurs. This is extraordinarily creative, because a 3rd or 4th fill cask may not provide as much cask influence, but they can act as a sponge to soak up the previous liquid. This means that such a seasoned cask would deliver the flavours of the previous content without over-oaking the product. These seasoned casks are used for the various Omar whisky finishes.

Warehouse

Most of Nantou distillery’s warehouses are racked for easy access to the individual cask. Amongst the racked warehouses, Nantou distillery also has a specially designed warehouse with space for future tasting events. This warehouse has an architecture heavily influenced by the sherry bodegas in Spain. The casks stacked up to three high and is a mimic of the solera system in a sherry bodega. Though the ceiling is lower, the arcs near the ceiling are similar to Bodegas in Spain. As a comparison, these are some pictures of the bodegas I visited in Jerez de la Frontera. On the left is Bodega Diez Merito, on the right is Bodega Fundador.

 

Distillery Expansion

Omar is looking to expand its production capacity by adding 3 more pairs of wash and spirit stills! The distillery is also undergoing renovation to accommodate larger tour crowds. In addition, Omar is continuing to experiment with new and different finishes! It is an exciting time ahead for Omar whisky and Nantou distillery is a must go on your Taiwan trip!

 

Special thanks to Nantou Distillery, Chairman Chung, and Ben for this enjoyable experience!