Experience and evidence have taught distillers that the environment around a barrel impacts how its contents age, how it interacts with wood from the barrel and how much evaporation takes place.
In theory, when the temperature rises, the whiskey expands, penetrating the cask more (and the thirstier the angel’s share^ becomes). As the spirit seeps into the pores of the barrel, it reacts with oak to extract colour, character and aroma. When the temperature cools, the whiskey shrinks, and flows back out of the wood along with the extracted compounds from the barrel. The swing from hot to cold is called a ‘heat cycle’ and allows the whiskey to develop its sweet, oaky flavours.
Whisk(e)y producing regions around the world have different climates. Melbourne is deemed to have an extreme climate when compared to other whisk(e)y regions such as Scotland and the United States. Our Master Distiller, Ian Thorn, analysed the climatic data.
The seasonal temperature fluctuation of Kentucky, USA (Fig 9) has greater swings when compared to Scotland (Fig 10), which has steadier weather and year-round climate consistency^^. However, compare both Kentucky and Scotland to Melbourne, and you can see Melbourne naturally has a more extreme maturation climate, with a greater temperature range and higher maximum temperature.
Figure 9 compares Melbourne (Bureau of Meteorology, 2020) in blue to Louisville in the United States (National Weather Service, 2020) in orange over 30 years of data.
Figure 10 compares Melbourne (Bureau of Meteorology, 2020) in blue to Perth in the highlands of Scotland (Met Office, 2020) in orange over 30 years of data.
To everyday Melbournians it seems impossible to decode the mystery of the sky, notoriously and often colloquial referred to as having ‘four seasons in a day’. This is due to Melbourne sitting within a temperate zone (between tropics and polar regions), not unlike two great weather gods at war. We see the semi-arid heat coming down from the warmer regions to the north in summer, and the cool Antarctic oceanic winds from the south during winter. This fluctuating climate is the result of some interesting geographical aspects at play.
We keep our warehouse in Brunswick, Melbourne at ambient temperature, allowing the whiskey to succumb to the impulses of the weather. When compared to Kentucky and Scotland, this results in whiskey with stronger oak influence and oak extractive characters. The liquid will be considerably different to whisky from Scotland, presenting as a lot bolder with more colour and sweetness.
How and where the barrels are stored also play a role on the spirit. In 1879, Frederick Stitzel invented the modern style of barrel warehousing - storing barrels on thin planks rather than solid wooden platforms - allowing the entire exterior surface of the barrel to be exposed to the elements. As for the internal location within the warehouse, temperature, airflow, humidity and other factors, can all impart unique characteristics to the liquid (barrels at the top of the warehouse generally experience higher temperatures than those at the bottom, and therefore age more rapidly). It could be said that every area of the warehouse has its own personality, if you will.
Using Melbourne’s unpredictable and varied weather to our advantage, we are able to create our distinctly flavourful spirit with its rye spice. It’s a true Melbourne whiskey that reflects the city of where it has been made.
Weather is just one element that influences our rye. Our team is fanatical about researching and delving into what makes our product unique. As we continue to uncover and share these stories with you, hopefully you discover something new.
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^During maturation a small amount whiskey evaporates through the wood and into the atmosphere, known as the giving the angels their share. In Melbourne we see the same Angel's share after 2-3 years maturation, as roughly 12-15 years in Scotland.
^^Interestingly, Masataka Taketsuru, founder of Japan's Nikka Whisky, chose the location of his Yoichi distillery in Hokkaido because of the region's similar weather conditions to Scotland. Meanwhile, due to their hot, humid climate, Taiwan's Kavalan ages its whiskies for a fraction of the period that traditional Scottish whiskies do, and are gaining a cult following around the world. Armut in India also use its extreme maturation climate to their advantage. Bangalore, where the distillery is located, experiences a tropical savanna climate with winter temperatures rarely dropping below 12C and summer temperatures rarely exceeding 35C.