Louis Pasteur seems like he was a sound chap. Granted, he somewhat rudely refused to shake hands and maintained what maybe described as an anti-social distance during conversations. We do however have him to thank for a life unmarred by rabid mouth-foaming, the enjoyment of a bacteria-free glass of ice cold milk, and stamping out several other ghastly maladies. As fans of whisky, we can also be grateful that he took a break from his milk bothering ways in order to study the process of microbial fermentation. His work on aerobic and anaerobic fermentation forms the basis of understanding how many of the tastiest foods are produced and importantly, how alcohol is created in our favourite drams.
What our ancient ancestors knew, long before Louis fired up his bunsen burner, is that fermentation is transformative. It unlocks flavours naturally existing in the substrate of foods and coaxes them out, developing depth and unravelling richness. Tasting grain from the malting floor of the distillery is rather disappointing, but that same grain, once fermented by yeast is transformed and well on its way to becoming tasty whisky.
Since fermentation is also one of the oldest methods of food preservation, it is used throughout the world, with each culture having its own tradition. From tangy Teutonic sauerkraut to the earthy richness of miso, the dark bitterness of coffee, and the breathy esters of certain whiskies, fermented products typically have a strong terroir, a sense of place. The water, the microflora and even the air used in production contribute unique flavour compounds. These fermented foods encapsulate a moment in a season. While in whisky making there are many factors influencing flavour, fermentation with its fruity aromas remains a key building block in the creation of flavour balance.
In my kitchen, I use many fermented ingredients. The most common is local sourdough. In contrast to whisky, with its myriad flavour influences, sourdough’s flavour is predominantly a result of its fermentation and by extension, environment. While the core ingredients are the same, the production differs dramatically and sourdough is a couple of steps closer to the raw materials.
My local bakery, Arun is located in the upper room of a converted church in the old part of Dublin. As you enter, the smell of sweet, fresh flour hangs in the air. There is something else too, a savoury smell, with a hint of ripe fruit and a puff of grainy sweetness. I look around in search of the source and it reveals itself with a gurgle. Nestled in a cool spot in the corner is the constantly fermenting mash that forms the DNA of Arun’s bread. A bubble rises to the surface of the gloomy liquid and Vlad, a Czech master baker, casts an attentive eye over the ‘animal’ which is ‘fed’ daily with water and flour. It is 2pm now; Vlad will be here until 6am tomorrow morning. His bakery ferments long and slow, allowing a depth of flavour to develop in the starter. If rushed, the bread will turn bitter, tasting flat and of sour vinegar.
Vlad speaks about the starter as if it is alive, ‘a member of the family’ and as I watch it warily out of the corner of my eye it does indeed seem sentient. It takes its flavour from the flour, which has a range of bacteria and yeast in it, from the water running through the area’s ancient pipes, and the atmosphere. The bread is very much ‘of the place’. Vlad explains: “If you get a starter off me, in a few weeks, it will be different, the bread won’t taste like it was made here.” These starters are the lifeblood of his bread and he speaks with tenderness about them. “It doesn’t matter how many pages of formulas you read, the mathematics that are applied: you need to have the feeling inside of you, to see when the starter is going well or not. You need to be able to care about it, you can’t do it just by the formula. You need to look after it.”
There is a reason that Malt Mill could never make Laphroaig or that Jim Rutledge protects his five unique yeast strains with such care.
I chat about this with Alex Chasko, the towering, booming voiced Distiller at Teeling Whiskey Company. In his former role as Innovation Manager at Kilbeggan Distillery, true to title, he experimented with all manner of off-the-wall mash bills, yeast strains and even spontaneous fermentation. “It is difficult to capture fermentation flavours in the still” he explains, “and a lot of aggressive fast acting yeast is being used, but when those eatery yeasty compounds come though, they can add real depth of character to a whisky. However there are so many influences on the flavour of whisky: the fermentation, distillation, maturation, even finishing, that the hefty fruit aromas that may come from the yeast are part of a larger flavour profile.”
According to Alex there are so many factors to consider in whisky production, fermentation flavours may not survive distillation, or might be overwhelmed by the cask. He agrees however that similar to a bakery, there is unique microflora in each distillery, especially in those with wooden wash backs. “I love the idea that compounds that exist in the distillery itself contribute flavour to the end product.”
I leave the bakery with a loaf of bread tucked neatly under my arm, still warm from the oven. A horse and trap clops along the cobblestoned street and I instantly recognise the hint of ripe fruit I smelled in the starter and marvel at how slow, careful fermentation has allowed it to amplify and thrive.