How is Bruichladdich Islay single malt Scotch whisky made

1. Ingredients

We distil Bruichladdich Islay single malt Scotch whisky using Scottish barley, yeast and local water from An Torran Reservoir, above the distillery.  A quarter of our barley is grown on Islay itself by local farmers; we also use organic and heritage varieties such as the ancient landrace, bere barley.  Peat is arguably a fourth ingredient. 

While other distillers also often add E150 caramel food colouring, Bruichladdich is always natural whisky, non-chill filtered and colouring free.


2. Malting

Prior to distillation, barley is subjected to a process called malting. Malting entails soaking the barley in water for two or three days to encourage germination, developing enzymes which convert the starches into sugars needed for fermentation. Growth is then arrested by drying the grain in a kiln. Nowadays it is common to use large, hot air dryers, which speed up the process and increase efficiency.

Traditionally distilleries would use whatever fuel sources were available locally to power their kilns – be that wood, coal or, as was common on Islay, peat. The smoke or 'reek' from the fuel-source inveigles itself into the grain and has a tangible impact on its  flavour. The difference between peated whisky and unpeated whisky is therefore a function of the fuel source that has been used in drying the malted the barley. 

We distill whisky using barley that has been peated to three different levels. Bruichladdich whiskies are unpeated. Port Charlotte whiskies are heavily peated and the experimental Octomore expressions are in a category of their own, the most heavily peated whiskies in the world.

Tracing the origin of our malting barley is vitally important to us and often involves small batch sizes sourced from individual farms or even fields. This commitment to provenance and traceablility combined with the complexity of our different peating levels demands very specialised handling by our maltsters. We are fortunate to enjoy a long-term relationship with Bairds of Inverness who have the expertise and patience to deliver to our exacting requirements.


3. Milling And Mashing

Malted barley is delivered to the distillery from Bairds by truck and stored in one of six individually accessible bins, enabling us to store different varieties or batches from different farms at the same time. The malt is mechanically dressed, weighed and then ground in the Boby Mill, dating from 1913.

Malted Barley arrivingThe grading of the resulting coarse flour or 'grist' is checked manually, before it is mixed with hot water and poured into our open-topped mash tun. After steeping to dissolve the sugars, the sweet liquid is drained off and sent forward to the washbacks for fermentation. To increase sugar extraction a second water is then added to the mash tun, which is again drained off to go forward to the washbacks. Water is then added a third and fourth time, with each retained to become the first and second waters of the subsequent mash.

After the fourth water has been drained off, we are left with a high-protein, low-carbohydrate porridge called 'draff', which is fed to Islay's cattle, part of what we like to call "the virtuous circle".

Bairds malt our barley using a saladin box, in which the malting and drying take place in the same container over a period averaging five days. In the case of peated barley for Port Charlotte and Octomore the peat is absorbed into the grain slowly during the whole period, rather than for an initial intense burst, which is often the case using hot air method.


4. Fermenting

The sugars in the sweet 'wort' then need to be converted into alcohol; this happens in the tun room, in huge vessels called washbacks. At Bruichladdich we still use wooden washbacks of Douglas Fir (sometimes known as Oregon Pine). Unlike the majority of Scotch whisky makers, we have not converted to stainless steel, preferring to adhere to traditional methods.

Fermenting process in whisky making

Our mash men use two different strains of distillers yeast, 'Mauri' and 'Kerry', which act at different rates at different temperatures. The yeast converts the sugars in the wort to alcohol, producing a sort of barley beer called 'wash'. Once the 'abv' reaches around 7%, the yeasts will stop working and the wash can go forward into the still house for distillation.

The careful control of fermentation is vital as it plays a key role in determining the character and flavours in the spirit to come.


5. The Wash Still

The Wash StillThe wash is first distilled in the two wash stills, traditionally made of copper because it is an excellent conductor of heat and because it is effective at neutralising impurities and thereby eliminating some of the less agreeable ethanol notes, sulphurous ones in particular. It is now mandatory for all single malt Scotch whisky to be distilled in copper pot stills.

Each wash still is charged with wash from the washbacks and gently heated using steam coils that sit in the body of the still. The control of the distillation is vital, sufficient heat being applied to vaporise the alcohol without the vessel boiling over. The vapour evaporated in the wash still is converted back to liquid via a water cooled condenser and is known as 'low wines' at approximately 20% abv.

The wash still at Bruichladdich


6. The Spirit Still

The low wines are further distilled in spirit stills with only the 'heart of the run' or 'middle cut' deemed fit for casking. 

When distillation in the spirit still begins, the high alcohol liquids that evaporate in advance of the middle cut are called 'the heads' or 'foreshots', and contain compounds which are undesirable in the finished spirit. As distillation progresses, the stillman makes a judgement on when to switch from the foreshot to the middle cut based on hydrometer measurements, a misting test with water and nosing the spirit.

The Spirit Still.  Part of the whisky making process here at Bruichladdich

The middle cut is then collected for maturation in casks.

When the abv. of the middle cut drops below the middle cut range the liquids that follow it are 'the tails', which also contain unwanted compounds. Collectively the heads and tails are called 'the feints' and they will be re-distilled along with the next batch of low wines. The residue left behind following the distillation, called 'pot ale', is primarily water and spent yeast with traces of copper. This is harmlessly dispersed at sea. 

Finding the right balance of flavour and alcohol is key to the distiller's art. Each distillery will select its own middle cut, appropriate to the whisky it is distilling. At Bruichladdich this middle cut differs for each spirit, each barley type, each peating level; it is judged carefully by taste and can vary from year to year as the stillman judges the essential quality of that particular spirit run. Results are recorded by hand in a book. For many distillers this process has become computerised, but at Bruichladdich each stage of the production is manually controlled. The stills at Bruichladdich are tall and narrow, designed by the Harvey Brothers in 1881 to produce a light, elegant and floral spirit. 

Bruichladdich's spirit still's are tall

7. Maturation

By law, single malt Scotch whisky must be matured in Scotland in oak casks, not exceeding 700 litres in capacity, for no less than three years. However, maturation does not necessarily need to be at the distillery where the spirit was created and much of the spirit on Islay is shipped to large warehousing complexes on the mainland close to bottling plants and the facilities major cities provide. At Bruichladdich all of our spirit is matured for all its life on Islay because we believe that our salt laden marine environment plays a vital part in forming its character

Muration of the whisky

Age is not the only factor in determining character and quality during the maturation of single malt Scotch whiskies. The quality, provenance, history and style of cask used is of fundamental importance. Oak is low in resins but rich in organic chemicals, which over time impart their own flavours to the whisky, but the rate at which the wood imparts these flavours varies significantly. The alcohol content of the whisky falls over time, losing about 2% of its strength per year. This loss is known as the angel's share. It must still contain 40% 'abv' at the time of bottling in order to qualify as Scotch whisky. This is one reason why very old whiskies are so rare. 

Most Scotch whisky is matured in American oak casks which were originally created for maturing Bourbon. This is partly because U.S. law forbids Bourbon makers from using casks more than once and for historical reasons of availability. The majority of Bruichladdich is matured in ex-Bourbon barrels, but we have over 200 different cask types maturing in our warehouses here, including sherry, rum, rare wine and fresh oak casks from all over the world. 

Muration of Bruichladdich's whiskies on Islay

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