Cooks are getting into pretty pickles these days, and for good reason.
It gives bubbly its fizz, stilton its funk, Sauternes its noble sweetness.
It instils umami in soya sauce and suavity in the tobacco of your postprandial cigar. It raises bread, knits tempeh together, detoxifies buah keluak, and exalts your cup of tea, coffee or cocoa far beyond muddy brown water. It also happens inside you – in fact, you wouldn’t be able to live a normal life without it.
We’re talking about fermentation, of course. As global gastronomy trends continue their current swing towards sustainably and traditionally produced foods, home and restaurant cooks are readopting and retooling ancient culinary practices – and prime among these, for age, diversity and sheer effectiveness, is microbial fermentation.
Cooks mostly work at a macro level, herding and kludging handfuls of ingredients into submission.
The modernist kitchen, with its thermometers and centrifuges, allows a tad more precision. In comparison, microbes employ enzymes to manipulate flavour and texture on a far more complex and fine-grained level, needing no extreme temperatures or conditions – just time. It’s no wonder cooks have befriended them since antiquity.
It is these millennia of coexistence and co-evolution with humans and their culinary activity that have led – science is not yet sure how – friendly microbes to “turn off ” the genes coding for lethal toxins, unlike their genetically very close cousins which still give us food poisoning. A few hundred species have become so “domesticated” that they live and thrive inside us, composing what doctors call the gut microbiome. Though far from giving us a final map of the microbiome, research heavily implicates it as having far-reaching influences on our immune system, metabolism, longevity and even brain functions.
Fermentation unlocks flavours, aromas and nutritive compounds otherwise inaccessible. Indeed, noted French chef Yannick Alleno believes that terroir – the rootedness of flavour in geographical and cultural origin – is most profoundly expressed by fermentation. In their recent book Terroirs: Reflections of a Chef, Alleno and co-author Marie-Claire Frederic, a fermentation expert, point out that many French foods depend on microbial action for their terroir-specific signature flavours: wines, cheeses, cured meats, sourdough breads.
Alleno ferments vegetables, cooks them sous vide, then concentrates their juices with various lowtemperature methods, obtaining essences with extended “caudalie” – the persistent duration of aroma on the palate – and what he calls “wavelength”, an extra depth and resonance of flavour. In his view, fermentation “reveals all the textures and tastes of a terroir’s living material”, providing “nouns” acted on by the “verbs” of precise cooking.
Among the most ubiquitous and industrious “noun” generators are the lactobacillus species, found naturally in or on many ingredients. They add zip to everything from lambic beers and Shaoxing wine to cacao, yogurt and the It garnishes of the moment: kimchi and other lacto-fermented pickles now starring at a restaurant near you. Lactobacilli create an acidic, anaerobic environment hostile to “bad” microbes but favourable to friendly species, for the net result of shelf-stable pickles playing bright and sustained chords of sourness.
Another microbe, Aspergillus oryzae, is grown on cooked rice to make koji, the traditional starter for many Asian rice and legume ferments. Over the past decade, a salted koji slurry called shio koji has become hugely popular among Japanese cooks: it tenderises, deeply seasons and bestows umami on whatever it touches, as its enzymes break down proteins, carbs and fats to respectively liberate amino acids, sugars and fatty acids.
Many chefs are capitalising on koji’s power in intriguing ways.
Momofuku’s David Chang uses it to make nut- and lentil-based miso analogues he has christened (and trademarked) “hozon”. Ohio chef Jeremy Umansky grows ghostlywhite koji crusts on meat and seafood cuts, which attain charcuterie-like tenderness and taste intensity in just days. Other pioneers are using koji to transform protein sources such as cheese and eggs into wholly new foods and condiments.