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Barrels have a profound impact on whisky maturation. They influence its flavour, aroma, colour, and overall character. It is during maturation that 70-80% of whisky’s flavour is developed, and where the spirit gains 100% of its colour.

Here are some key effects that barrels have on whisky maturation:

1. Flavour Development: Barrels contribute significantly to the flavour profile of whisky during maturation. The wood of the barrel imparts various compounds, such as lignin, tannins, and hemicellulose, which interact with the whisky over time. This interaction can add flavours such as vanilla, caramel, toffee, and spice notes to the whisky.
2. Oak Extractives: Oak, commonly used in whisky barrels, contains compounds like lactones, vanillin, and eugenol, which are extracted into the whisky during maturation. These compounds contribute to the characteristic oak flavours found in matured whisky.
3. Maturation Compounds: As whisky ages in barrels, it undergoes a complex series of chemical reactions. The interaction between the whisky and the wood leads to the extraction of compounds from the wood, including sugars, phenols, and lignin derivatives. These compounds contribute to the development of flavours, adding complexity and depth to the whisky.
4. Oxidation: Barrels allow a controlled amount of oxygen to enter the whisky during maturation. This exposure to oxygen triggers oxidation reactions, which can soften harsh flavours, integrate different components, and promote the development of complex flavours and aromas.
5. Filtration and Clarification: Barrels aid in the clarification of whisky by allowing sediment and certain particles to settle over time. This natural filtration process can result in a clearer and visually appealing product.
6. Maturation Environment: Barrels provide a unique environment for whisky maturation. The porous nature of the wood allows the whisky to breathe, while temperature fluctuations in the storage facility cause expansion and contraction, enabling the whisky to interact with the wood and extract flavours. These environmental factors contribute to the overall maturation process and influence the final product.
7. Previous Contents: The history of the barrel, including its previous contents, can have an impact on whisky maturation. Barrels that previously held other spirits like bourbon, sherry, or wine can impart residual flavours and characteristics to the whisky, adding additional layers of complexity.

Here’s an overview of each method:

Whisky Produced “On the Grain”

Production Process: Whisky produced “on the grain” refers to a production method where the entire mash, including the grain, stays with the product during fermentation and distillation. The grains are milled, mixed with water, and undergo mashing to convert starches into fermentable sugars. The resulting mash, including the solids, is then fermented and distilled. The 24-inch continuous distillation system at Greenbanks is optimised for distilling on the grain.

Flavour Profile: Whisky produced “on the grain” tends to have a fuller and richer flavour profile compared to whisky produced from separated liquid wort. This is because the presence of the grain solids during fermentation and distillation contributes additional flavours, textures, and complexities to the final spirit. The grain solids contain a variety of compounds, including oils, proteins, and husks, which can influence the character of the whisky.

Whisky Produced from Liquid Wort Separated from the Grain

Production Process: In this production method, the mash undergoes a separation process after mashing to separate the liquid wort from the grain solids. The liquid wort, which contains the dissolved sugars from the grain, is then transferred for fermentation and distillation, while the grain solids are discarded or repurposed. This process is most common when pot stills are being used, because of the potential for off-flavours due to Maillard (browning, like during cooking) reactions occurring as heat is applied to the pot during distillation.

Flavour Profile: Whisky produced from separated liquid wort generally has a cleaner and lighter flavour profile compared to whisky produced “on the grain.” The absence of grain solids during fermentation and distillation reduces the presence of certain compounds, such as oils and proteins, that can contribute to a heavier flavour profile. As a result, the whisky produced from separated liquid wort may exhibit more delicate flavours.

It’s important to note that the choice between producing whisky “on the grain” or from separated liquid wort depends on the type of equipment being used and the desired flavour profile and production goals of the distiller. Each method can result in distinct characteristics, and distilleries may choose one over the other to achieve specific flavour profiles or adhere to traditional production practices.

When producing spirit from grain, copper in the still plays the important role of removing sulphur compounds from the distillate vapour. Both pot and column stills produce high quality whiskies, but each type makes spirits with different flavour profiles and have their own specific advantages and disadvantages.

Whisky produced in column stills:

Continuous column stills, like Greenbanks’ Vendome 24-inch continuous system, can be run 24/7. They can also be set up for batch production but are most efficient when set up for continuous double-distillation. Continuous distillation means the still can keep running as long as there is finished ‘beer’ (fermented mash) available to pump to it. Running a continuous column still 24/7 is the best way to keep the column still in equilibrium.

Double distillation means that after the first pass (single distillation of 65% ABV in the beer still), ‘low wine’ flows via a condenser into a doubler (continuous pot still) and is distilled again to around 70% ABV in real time. As long as there is finished beer being pumped to the column, it will continuously produce a consistent quality new make from the doubler, which is then ready to be reduced to barrel strength.

The continuous column still design is very efficient in stripping out almost all the hearts and separating out all the unwanted alcohols, such as foreshots, heads and tails. Like on a pot still, these production parameters are created and set by the distiller, but only at the beginning of distillation until the vapour temperatures required to achieve consistent quality from the still are reached. As long as the incoming finished beer remains consistent, the still parameters (beer feed, steam rate, pressure, etc.) remain the same, thus producing consistent high-quality distillate.

Greenbanks’ 24-inch column still contains 19 perforated plates. Beer is pumped to the still at the 5th plate down from the top and cascades down the stripping plates below to the bottom of the still where it is pumped out to our stillage tank to be delivered to farmers for cattle feed or other agricultural purposes.

Boiling points of volatiles (alcohol, congeners, acids, esters, etc) are all different. They separate at different levels within the column, some at the top, middle or bottom and a portion of some always go over with the ethanol vapour.

The foreshots and heads are separated by venting them away from the still before they condense with the low wine vapour. This is accomplished by keeping the low wine above a certain temperature before it can be condensed and flow into the doubler for its second distillation.

The hearts and tails arrive together in the doubler as a low wine, but the hearts will volatilise at a much lower temperature than the tails, which in the presence of higher alcohol percentages will increase the tails boiling point. The hearts are distilled from the doubler around 87oC producing a ~70% ABV distillate. The tails remain in the doubler liquid and do not come out in the vapour.

Column stills are more efficient, and their design makes them more effective at separating the different alcohols and congeners than pot stills. They tend to produce spirit that is both smoother and higher in purity than that which runs of pot stills.

Whisky produced in pot stills:

Pot still distillation is a ‘batch’ process with slower distillation rates and less overall efficiency. Pot stills are designed such that the distiller ‘charges’ (fills) the still with a single or partial batch of ‘wash’ (fermented wort) then heats it up until the distillation is complete and repeats the process for every batch.

The distiller has a lot of manual control over what ends up in the final spirit. They can make the spirit lighter or heavier in congeners (aroma and flavour compounds) based which fraction of the spirit they collect due to the ‘cuts’ they make during distillation.

Cuts are where the distiller either empirically or by taste chooses to separate the distillate sequentially into foreshots, heads, hearts and tails as the still is heated through a batch distillation run.

1. Foreshots: the first distillate to be produced from the still. These contain low-boiling volatiles like methanol. The distiller may choose to discard this part of the run.
2. Heads: a mixture of more low-boiling volatiles like aldehydes and amyl alcohols, will start coming over next. Heads are collected and will then be recycled back into the next batch to reclaim some of the good ethanol that is smeared in with the heads vapour.
3. Hearts: the quality ethanol the distiller wants to capture. Hearts are collected in the middle of the distillation run and comprise more than half of the volume of distillate.
4. Tails: come off the still towards the end of distillation when the alcohol is almost fully vapourised and the boiling point of the remaining wash is now much higher than at the beginning. This volatilises (turns into vapour) an increasing concentration of congeners (which are very grainy and astringent) along with alcohol as the distillation progresses toward its end where there is no longer enough alcohol remaining in the pot to justify the energy required to distil it. Tails are collected and mixed with heads to be recycled into the next batch.

The distiller may perform a single, double or triple distillation, but for each distillation the process must start over. The number of casks that can be filled is dependent on the size of the pot still. The consistency of the flavour of pot-distilled whisky depends upon the distiller making consistent cuts and operating the still at consistent temperatures.

The ageing duration for whisky in Tasmania, as in any whisky-producing region, can vary widely depending on several factors. Tasmania has gained recognition for its whisky production in recent years, and its climate plays a unique role in the maturation process.

Here are some considerations for ageing whisky in Tasmania:

1. Climate: Tasmania’s climate is known for its cool and temperate characteristics, somewhat similar to the climate in Scotland. However, it experiences greater temperature variation, with relatively cold winters and warm summers, and has much lower humidity. This climate can accelerate the interaction between the whisky and the wood in the casks, potentially leading to quicker maturation compared to regions with more stable temperatures.
2. Cask Type: The type of cask used for ageing whisky in Tasmania will influence the ageing process. Common cask types include American oak barrels, sherry casks, and wine casks. The choice of cask and its previous use can impact how long the whisky should be aged to achieve the desired flavour profile.
3. Whisky Style: The style of whisky being produced in Tasmania can vary, from single malts to blends and experimental expressions. Each style may have its own ideal ageing duration, which distillers determine based on flavour development and their desired final product.
4. Personal Preferences: The ideal ageing duration for whisky in Tasmania, as in other regions, can also be a matter of personal taste. Some Tasmanian distillers and enthusiasts prefer younger, more vibrant expressions that showcase the influence of the cask and grain, while others may favour longer ageing for increased complexity and depth of flavour.
5. Trial and Error: At Greenbanks, we will experiment with different ageing durations to determine what works best for our specific whiskies. Over time we expect to release a range of expressions with varying ages to highlight the impact of age in Tasmania’s climate and also cater to different consumer preferences.

In summary, there isn’t a fixed rule for how long whisky should be aged in Tasmania. At Greenbanks, like other whisky distilleries around the world, we will take into account our specific goals, climate conditions, cask choices, and flavour objectives when determining the optimal ageing duration for our whisky.

The choice of grains used in whisky production has a profound impact on the flavour and character of the final whisky. Different grains contribute distinct flavours and characteristics to the whisky. Here’s how various grains can influence the flavour of whisky:

Malted Barley:

• Flavour Profile: Malted barley is known for its rich and complex flavour profile. It can contribute notes of malt, honey, toffee, cereal, and nuttiness. The malting process also produces enzymes that convert starches into fermentable sugars, contributing to the sweetness of the whisky.
• Whisky Examples: Single malt Scotch whisky, Irish pot still whiskey, and some American craft whiskies use malted barley as the primary grain. These whiskies often have a full-bodied and malt-forward character.

Corn:

• Flavour Profile: Corn imparts a sweet and mellow flavour to whisky. You can expect notes of caramel, vanilla, toffee, and a creamy sweetness. Corn-based whiskies are often smoother and less spicy compared to those made with other grains.
• Whisky Examples: Bourbon is the most famous whisky style that predominantly uses corn as its main grain (at least 51%). This contributes to bourbon’s sweetness and rich caramel notes.

Rye:

• Flavour Profile: Rye grain adds a spicy and fruity character to whisky. You might notice flavours like black pepper, cinnamon, nutmeg, and sometimes a hint of fruitiness, such as apples or citrus. Rye whiskies can be bold and complex.
• Whisky Examples: Rye whisky, often associated with North America, includes American rye whiskey and Canadian rye whisky. These whiskies are known for their spicy and robust profiles.

Wheat:

• Flavour Profile: Wheat imparts a softer and smoother character to whisky. It can bring flavours of caramel, honey, creaminess, and a gentle sweetness. Wheat-based whiskies are often approachable and less spicy.
• Whisky Examples: Wheat is commonly used in the production of wheat whisky, which is less common than other styles but known for its mild and easy-drinking profile.

Barley (Non-Malted):

• Flavour Profile: Non-malted barley, when used alongside other grains, contributes a different set of flavours. It can add a nutty and cereal-like character with a subtle sweetness.
• Whisky Examples: Some blended Scotch whiskies and certain Irish whiskey blends may include non-malted barley as part of their grain composition.

Other Grains (Rice, Oats, etc.):

• Flavour Profile: Other grains can be used in whisky production, though less commonly. Rice can add a clean and neutral character, while oats can contribute a creamy and oatmeal-like quality. The impact on flavour varies depending on the grain and its proportion in the mash bill.
• Whisky Examples: Some experimental and craft distilleries may use alternative grains to create unique flavour profiles.

In summary, the choice of grains is a fundamental factor in shaping the flavour of whisky. Each type of grain brings its own set of flavours and characteristics, and the combination of grains in the mash bill can result in a wide range of flavour profiles, from sweet and smooth to spicy and bold. Additionally, the distillation and ageing processes further influence how these grain-derived flavours evolve in the whisky over time.

The key difference between malted grain and unmalted grain lies in the process of malting. Malting is a crucial step in the production of many types of alcoholic beverages, including whisky.

Here’s how malted grain and unmalted grain differ:

Malted Grain:

1. Malting Process: Malted grain, typically barley, goes through a malting process. During malting, barley grains are soaked in water to allow them to germinate. After a few days, germination is halted by drying the grains in a kiln.
2. Enzyme Development: During germination, enzymes are activated within the barley grain. These enzymes, particularly amylase and protease, convert starches in the grain into fermentable sugars. This enzymatic activity is crucial for the fermentation process in brewing and whisky production.
3. Flavour Development: Malting also contributes to the development of various flavours and compounds in the grain. The kilning process can influence the colour and flavour of the malted barley, contributing to the malt’s character.
4. Whisky Production: In whisky production, malted barley is often used to make single malt whisky. The malted barley is mashed and fermented to create a wort, which is then distilled to produce whisky. Single malt whisky is known for its complex and often fruity or malty flavours, partly due to the malting process.

Unmalted Grain:

1. Absence of Malting: Unmalted grain, such as corn, wheat, rye, or barley, does not undergo the malting process. Instead, it is used in its raw grain form.
2. Starch Source: Unmalted grain primarily serves as a source of starch in the production of whisky. These grains have not undergone the enzymatic changes that occur during malting.
3. Flavour Profile: Unmalted grains tend to contribute different flavours to the final product. For example, corn is known for its sweetness, while rye can add spiciness.
4. Whisky Production: Unmalted grains are commonly used in the production of various types of whisky, including bourbon (which uses corn), rye whisky (which uses rye), and some blended Scotch whiskies (which can include unmalted barley or other grains). These grains are typically mashed, fermented, and distilled to create the base spirit.

In summary, the main difference between malted grain and unmalted grain is the malting process. Malted grain undergoes germination and enzymatic changes, resulting in the development of sugars and complex flavours. Unmalted grain is used in its raw form and primarily provides starch for fermentation, contributing different flavour characteristics to the final product. The choice of grain, malted or unmalted, plays a significant role in shaping the flavour and character of whisky.

Yeast plays a crucial role in whisky production and can have a significant impact on the final flavour and aroma of the whisky.

Here’s how yeast influences the flavour profile of whisky:

• Fermentation: Yeast is responsible for fermenting the sugars in the mash into alcohol and carbon dioxide during the fermentation process. As yeast consumes the sugars, it produces various by-products, including alcohol, heat, and a wide range of flavour compounds known as congeners. These congeners contribute to the flavour and aroma of the whisky.
• Esters: Yeast produces esters during fermentation, which are responsible for fruity and floral notes in whisky. The specific esters produced depend on the yeast strain used and fermentation conditions. For example, some yeast strains might produce esters with apple, pear, or citrus-like aromas.
• Fusel Alcohols: Yeast can also produce fusel alcohols during fermentation. These higher alcohols can have a strong, sometimes pungent, aroma and taste. While in excess, fusel alcohols can be undesirable, in controlled amounts, they can add complexity to the whisky’s flavour.
• Phenols: In some whisky styles, particularly peated whiskies like Islay Scotch, yeast is exposed to phenolic compounds from the peat during fermentation. This results in the formation of smoky and medicinal notes in the final whisky’s flavour.
• Temperature and Fermentation Time: The temperature at which fermentation occurs and the duration of fermentation can also influence the flavour. Cooler fermentations may lead to cleaner and fruitier flavours, while warmer fermentations can produce more complex and ester-rich profiles.
• Yeast Strain: Different yeast strains have unique characteristics and can produce various flavour compounds. Distilleries often have proprietary yeast strains that contribute to the distinctiveness of their whisky.
• Yeast Health and Viability: The health and viability of the yeast cells also play a role. Healthy yeast cells are more efficient at fermentation and can contribute to a cleaner and more predictable flavour profile.
• Yeast Reuse: Some distilleries reuse yeast from previous fermentations, a process known as “backset.” This can lead to consistency in flavour over time and may also introduce subtle nuances.
• Distillation and Maturation: While yeast primarily impacts the flavour during fermentation, some compounds produced by yeast can carry over into distillation and maturation. The interaction between yeast-derived compounds and the wood of the ageing barrels can further influence the whisky’s flavour.

In summary, yeast is a critical element in the whisky-making process that contributes to the development of a wide range of flavour and aroma compounds. Distillers carefully select yeast strains and control fermentation conditions to achieve their desired flavour profiles, making yeast management a key factor in the production of unique and distinctive whiskies.

Tasmanian whisky has gained recognition and acclaim in the whisky world for several unique characteristics and qualities that set it apart. Here are some of the key factors that make Tasmanian whisky unique:

• Climate: Tasmania’s cool, maritime climate is conducive to whisky ageing. The island experiences significant temperature variations, with cool winters, warm summers and relatively low humidity. These temperature fluctuations accelerate the interaction between the whisky and the oak casks, leading to quicker and more dynamic maturation. This can result in well-balanced and flavourful whiskies in a shorter time compared to regions with more stable climates.
• Pure Water: Tasmania boasts some of the purest and cleanest water sources in the world, a crucial ingredient in whisky production. High-quality water is used for mashing, fermentation, and dilution, contributing to the overall character of Tasmanian whisky.
• Local Ingredients: Tasmanian distilleries often use locally sourced barley and other grains, which can impart unique regional characteristics to the whisky. The island’s agricultural diversity allows for experimentation with different grain varieties and flavours.
• Craftsmanship: Many Tasmanian distilleries are small, boutique operations, emphasizing craftsmanship and attention to detail. This artisanal approach allows for experimentation and innovation, resulting in a wide range of whisky styles and expressions.
• Innovation: Tasmanian whisky makers have been known for their innovative approaches to whisky production. They have embraced experimentation with different cask types, including ex-sherry, ex-port, and wine casks, which can impart distinctive flavours to the whisky.
• Environmental Considerations: Tasmanian distilleries often prioritize sustainability and environmental consciousness in their production processes. This commitment to sustainability can extend to using renewable energy sources, managing water resources responsibly, and employing eco-friendly practices.
• Award-Winning Quality: Tasmanian whiskies have received numerous awards and accolades on the international stage, attesting to their quality and appeal to whisky enthusiasts worldwide.
• Distinctive Flavour Profiles: Tasmanian whiskies are known for their complex and unique flavour profiles. They can exhibit a wide range of characteristics, from fruity and floral notes to hints of spice, honey, and oak. The shorter ageing periods in Tasmania, influenced by the climate, can result in whiskies that are vibrant and full of flavour.
• Collaboration: Tasmanian whisky makers often collaborate with other distilleries and wineries, sharing casks and expertise. This cross-pollination of knowledge between the wine and whisky industries can lead to innovative and unique expressions.

In summary, Tasmanian whisky is unique due to its climate, local ingredients, craft approach, innovation, and distinctive flavour profiles. It has gained a reputation for quality and continues to be an exciting and evolving part of the global whisky landscape.

Whisky (or whiskey) is a distilled spirit that comes in various styles, each with its own unique characteristics and production methods.

Here at Greenbanks we’ve built our unique distillery with features that provide both the ability and flexibility to make whisky from any grain, in any style. We have the specialised equipment and knowledge that enables us to work with our contract partners to produce their desired whisky profile; from R&D to full scale production, from handling and milling of grain, through to mashing, fermentation, distillation and maturation.

The main types or styles of whisky made around the world include:

1. Scotch Whisky:

• Single Malt Scotch: Made from 100% malted barley at a single distillery and distilled in pot stills. It’s known for its diverse flavour profiles, often influenced by the region in Scotland where it’s produced (e.g., Islay, Speyside, Highland).
• Blended Scotch: Combines single malt and grain whiskies from multiple distilleries. Blended Scotch is often smoother and more approachable than single malts.

2. Irish Whiskey:

• Irish Pot Still Whiskey: Made from a mixture of malted and unmalted barley and distilled in pot stills. It has a creamy, fruity, and slightly spicy character.
• Irish Malt Whiskey: Made from 100% malted barley and distilled in pot stills or column stills. It’s typically smoother and lighter than pot still whiskey.
• Blended Irish Whiskey: Combines various types of Irish whiskey, including malt and grain whiskies, for a balanced and approachable flavour.

3. American Whiskey:

• Bourbon: Primarily made from at least 51% corn and aged in new charred oak barrels. It has a sweet and full-bodied flavour with notes of caramel, vanilla, and oak.
• Rye Whiskey: Made from at least 51% rye grain. Rye whiskey tends to be spicier and more robust than bourbon.
• Tennessee Whiskey: Similar to bourbon but filtered through sugar maple charcoal before aging, known as the Lincoln County Process.
• Corn Whiskey: Made from at least 80% corn and often has a sweet and mild flavour. It’s less common than bourbon and rye.

4. Canadian Whisky:

• Typically made from a blend of grains, including corn, rye, wheat, and barley. Canadian whisky is known for its smooth and light profile, with a hint of sweetness.

5. Japanese Whisky:

• Modelled after Scotch whisky production techniques, Japanese whisky has gained international acclaim for its quality and craftsmanship. It comes in various styles, from light and floral to rich and peaty.

6. Other Whiskies:

• There are many other types of whiskies produced in different countries, including Welsh whisky, Indian whisky, and of course Australian whisky. Each has its own unique characteristics and production methods.

7. Specialty Whiskies:

• Some distilleries produce specialty whiskies, such as cask-strength, single cask, or limited-edition releases. These offer unique and sometimes rare flavour experiences.

It’s worth noting that terms like ‘Scotch’ and ‘Bourbon’ are protected by geographical indications (GI) that dictate, among many other details, where they are to be made – Scotland in the case of Scotch, and USA in the case of Bourbon. This means that, while Greenbanks can make products that are similar, we cannot make a product that can be called any name protected by a GI.

Each type of whisky is influenced by factors like ingredients, production methods and aging process, leading to a wide range of flavours and styles for whisky enthusiasts to explore and enjoy.

Contact our team to see how we can help you bring your whisky vision to life.