Meet the Team – Mike Duncan
Hello, I’m Mike, and I’m a distiller working for Mr Billy Walker! I don’t pretend to know it all and what I think I know is probably not 100% accurate. I’ve only been a distiller for six years. In this time, I’ve achieved a General Certificate in Distilling; I’m two-thirds of the way into gaining a Diploma in Distilling; and none of the spirit I’ve distilled has ever been sold in a bottle!
A few Instagram followers have been in touch and asked me some intriguing questions: @jon_bing_ham, if I was important enough to hire anyone, it would be you!
Q. How many tonnes of Scottish malted barley do you mash every week and are there any challenges with the process? @jamiehume94 and @donald.corbett.336
A. We mash 37.6 tonnes of Scottish malted barley every week (4x 9.4 Tonne mashes) and have two different malt suppliers. From my point of view, if we know the equipment adjustments (milling and mashing) needed to process malt from at least two suppliers, then we shouldn’t have any major issues with malt processing, quality, or supply. For a few weeks every year we throw peated malt into the mix which can bring its own processing challenges!
Mike with the mash ton
Q. How many litres of whisky have you distilled in your life? @whisky_travel_beard
A. Well, I started out my whisky apprenticeship running the mashing side at Ballindalloch Distillery and after six months, I moved onto the stills. That’s 2 years distilling at Ballindalloch (about 100,000 LPA/Yr) and 3.5 years distilling at GlenAllachie (averaging 550,000 LPA/yr). Let’s say I’ve distilled about 2.5million litres of spirit so far. And like I said, none of it has ever been sold in a bottle. I do wonder whether Ballindalloch or GlenAllachie will be the first distillery to sell a bottle of whisky that I’ve made…?
Q. Since the distilling process takes such a long time, what gives you instant gratification in your job? @kennyburns1971
A. When it comes to making spirit, GlenAllachie is a very efficient distillery. We regularly achieve 5-15 litres of alcohol more per tonne of malted barley than our Predicted Spirit Yield (PSY) says we should. That’s more to do with our process than any of my skills but I enjoy getting these positive results every week. Maybe because we’re performing so well, I don’t feel a great pressure around production volume. Of course, Billy’s always checking the quality of our spirit, but the whole ethos at GlenAllachie over the past 3 years has been to slow things down to generate more complex flavours in the wash and in the final spirit. I really appreciate working in this environment.
Q. Why have GlenAllachie doubled the fermentation time to 163 hours and what difference does this make to the spirit? @ffc1997
A. Well, the fermentation process produces many different chemical compounds as the yeast metabolises the sugars from the malted barley. At GlenAllachie we like to give the alcohols a lot of time to react and combine with the natural acids to form fruity esters. This probably reduces the alcohol content but adds more to the flavour profile. We then distil the stuff twice, so the more flavours we have before distillation, the better the chance we have of keeping those flavours in the final spirit and in the final whisky.
Q. How do the shape of our stills and the way we run them affect the flavour profile of our whisky? @jorn__veenstra, @whiskyspore and @lt3golfgti
A. For distillation to work, the alcohols and other chemical compounds in the Wash and Low Wines/Feints must have different levels of volatility: they need different amounts of energy (heat) to vaporise. At GlenAllachie, we’ve increased our distillation times by about 20mins. This means we’re choosing to apply that energy a bit slower by reducing the amount of steam that goes through the heating coils. I suppose we’re giving the chemical compounds less of a push on their way up the still. The result is that less of the heavy, lower-volatility compounds and more of the light, higher-volatility compounds make it into the final spirit. This can give a lighter, more fresh, floral, or fruity spirit character.
Copper contact via reflux also affects our spirit character. Our stills are lamp-glass shaped, which gives them a large, wide surface area of copper. As the alcohol vapour condenses against this copper surface, a chemical reaction takes place that removes sulphur compounds. As sulphur off-notes are removed, many of the other flavours and aromas become more prominent. Again, the slower distillation provides more time for these reactions to take place.
Q. Do the stills have names? @papa_dram
A. I can confirm that I’ve called the stills many names, especially Wash Still #2!
Phew! This light-hearted little blog post got a bit scientific at the end there, which is not what my job is like day-to-day. Mostly I look at volumes and timings on my four computer screens, but it does help to have some idea of what is going on chemically. If you have any questions for me, or maybe you’d like to hear from my Brewer (Production Manager), Phillip, then please send in your questions via social media. We’ll put another blog post out at some point and maybe give you a shout-out too.
Mike Duncan with our Brewer, Philip Murray
Thanks for now,
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