Fermentation is the visually unimpressive part of making whisky. But it is the most important – and mysterious – of all: sugars, dissolved from malted barley grist into Islay water, are consumed by yeast giving birth to over 100 different flavour compounds. It is here that a single malt whisky becomes the most flavour complex spirit known to man.
Many of the spirit’s complex flavours are created during fermentation, consequently, like winemakers, we believe the slower and more gentle, the purer and better – as long as nature decides, for we are in no hurry; what’s a few extra days out of 15 years? It is these flavours, supplemented by flavours from the oak casks, which will be developed by micro-oxygenation during the long years of maturation.
Stainless steel vats are of course cheaper to buy, easier to clean and simpler to maintain than wooden ones. But this efficiency was rejected by the great wineries of the world who have returned to wood because of its thermal qualities: fermentation generates heat, and by absorbing and redistributing it, the fermentation can be naturally extended to achieve extra purity and flavour. The ancient wood pores retain yeast traces that influence the added cultures, providing a calm, smooth, gentle simmer as they go about their bespoke business.
It is in the still house, where the “weight” of the spirit is created, and there that we have our experienced stillmen: there is no formula, no software that decides the all-important middle cut. In our view there are simply too many variables and idiosyncrasies to defer the art of distillation to a microchip. The stillman’s knowledge, acquired over decades, of each still’s peculiar ways allows the distillation to be finely balanced, like a surfer riding the crest of a wave, with the heat sensitively controlled to slow the spirit run to a gentle gurgle, a trickle distillation.
We have the time, the inclination, and the stubbornness, to be totally uncompromising.