Tasmanian Whisky Academy Intro to Distilling – Part Three

After leaving Moo Brew Brewery, the Intro to Distilling course enjoyed a lunch of beautiful local Tasmanian produce at Frogmore Creek Winery in the Coal River Valley. Just beyond the manicured gardens and fields of grapes sits an unassuming tin shed; many a tourist would sip their wine admiring the view without realising the tin shed is where Bill Lark’s famous award-winning Lark whisky is aged.

It was only a short trip from Frogmore Creek to the Cambridge-based Sullivans Cove Distillery. We were greeted at the distillery by Sullivans Cove Head Distillery, Pat Maguire, who wasted no time showing us where the whisky wash (from either Moo Brew or Cascade breweries in Sullivans Cove’s case) is pumped into the distillery. Sullivans Cove is set up to receive 12,000L of whisky wash at a time, although the distillery only operates a single 2,400L pot still. The whisky wash is transferred to a storage tank on the outside of the distillery to be pumped, when required, to the pot still inside. The distillery is open to the public for tours and cellar door sales throughout the business week and has a viewing platform overlooking the copper pot still, tucked away in a corner of the bond store. From 1996 – 2003, Sullivans Cove distillery occupied the old gas works site in Hobart and employed two people; the distillery was then sold and moved to Cambridge in 2004 where it now employs 12 people.

The distilling setup at Sullivans cove consists of a single 2,400L French designed (originally for brandy distillation) copper pot still, connected to a condenser via a lyne arm with a swan’s neck kink at the still end and six spirit collection tanks. The first step in the distilling process is to create 'low wine', which is what you are left with after the wash run or initial pass through the still. Whisky wash is pumped into the pot still from the wash receiving tank outside. Since Sullivans Cove start with 12,000L of whisky wash and only have a 2,400L still, they need to do five wash runs to process all the whisky wash. The still is filled and heated to 81˚C causing the alcohol to boil off but leaving most of the water behind. The vapour rises up the still and into the lyne arm where it partially condenses. So much of the distilling equipment is made of copper because copper chemically reacts with the condensing vapour. This property of copper was a serendipitous discovery, much like the effects of ageing spirit in wooden barrels. The copper reacts with sulphur in the vapour to form copper sulphate and draws unpleasant compounds and oils out of the spirit.

Next the spirit reaches the vertical column shaped condenser, where as the name suggests, the vapour is cooled and condensed into a liquid. The low wine is collected in the various storage tanks until all the whisky wash has gone through the pot still. At this point, the low wine is at about 25% ABV and is ready for the first of two spirit runs which will eventually become Sullivans Cove’s double-distilled newmake spirit. After the first spirit run, the spirit is transfer back into the still and the process begins again. This time the liquid that leaves the condenser is of a much higher alcohol concentration (around 71% ABV) and the copper strips away more unwanted compounds.

It is not a simple matter of just collecting all the liquid that comes out of the condenser however; more than one type of alcohol is distilled and not all alcohol is safe to consume. The first liquid distilled in a spirit run is mostly methanol, a strong smelling and poisonous alcohol. The distiller must separate this and other unwanted components in order to capture the ‘heart’ of the spirit run which is mostly ethanol. To achieve this, the distilled spirit is diverted at the beginning and end of each spirit run into a separate storage tank. The point when the spirit is diverted is called a cut and the first portion of cut spirit the ‘foreshots’ and the last portion the ‘faints’. The ‘fores & faints’ are not wasted, but rather added to the next spirit run since they still contain a portion of usable alcohol. Cutting the spirit can be an automated process or done manually as is the case at Sullivans Cove. You can smell, taste and sometimes see when the spirit run changes from mostly methanol to ethanol and a distiller uses all these indicators and their own experience to decide when to cut the spirit.

During those two or more years, the spirit and wood undergo an almost magical metamorphosis where the wood releases organic chemical compounds into the spirit that introduce new colour, flavours and aromas. 

The spirit that is produced from the distillation process is not yet whisky. In order to be legally labelled as Whisky, the freshly distilled newmake, must be aged in wooden barrels for a minimum of two years (in Tasmania) or three years (in Scotland). During those two or more years, the spirit and wood undergo an almost magical metamorphosis where the wood releases organic chemical compounds into the spirit that introduce new colour, flavours and aromas. Sullivans Cove do not print age statements on their bottles, but they do list the distillation and bottling dates so you can work out the age of the whisky for yourself; often around 10 years which makes it some of the oldest Tasmanian whisky available.

The final process is to bottle the aged whisky, but once again it is not as simple as syphoning the whisky straight from the barrel and into a bottle. The compounds released by the wood that impart so much flavour and aromas to the whisky have varying solubility depending on alcohol concentration and temperature. This means, that they will tend to solidify and clump together over time. There is nothing wrong with this other than the cosmetic effect of having a cloudy whisky or seeing sediment in the bottom of your bottle. For this reason, most whisky bottled under 46% ABV has undergone some form of filtration. Chill-filtration is a fast, industrialised process where the whisky is chilled to force the wood compounds to solidify so they can be removed from the whisky. This will produce the clearest whisky and is common where whisky is produced on a massive scale. The other method is called flocking. Flock is the name given to the solidified wood compounds that accumulate over time and Sullivans Cove employ the flocking method since they bottle their whisky at 40% ABV and in relatively small quantities; flocking requires a lot of time and space.

The barrelled whisky is poured into plastic containers and filtered water is added to bring the alcohol concentration down to a bottling level of 40% ABV. The diluted whisky is then left to sit for months at a time. As the whisky rests, the heaviest and least soluble wood compounds clump together and settle on the bottom of the containers. The whisky above the flock, is drawn off and placed into another plastic container so that the process can be repeated and the whisky drawn off again. I have been told that the whisky flock is quite delicious and is highly sought after for culinary purposes. Once the distiller is happy with the clarity of the whisky, it is bottled, labelled and ready for sale.

Having followed the whisky making process from malt to bottle, the Intro to Distilling course returned to Hobart. A lucky few who did not have to dash away, were met at Hadley’s Orient Hotel by none other than Bill and Lyn Lark and shared a dram or two with the first-family of Tasmania Whisky.

This concludes the three-part feature on the Introduction to Distilling Course but check back soon for an interview with Anne Gigney, Director of the Tasmanian Whisky Academy.