Spare a thought for ferment­ation. Without it, we wouldn’t have soy sauce, beer, cheese, wine, chocolate, sake, miso, yogurt, fish sauce, kimchi, vinegar and many other foods and drinks we take
for granted.

René Redzepi and David Zilber have thought long and hard about fermentation, as indicated by their new cookbook, The Noma Guide to Fermentation. Foodies will know of Redzepi as the chef-owner of Noma, in Copenhagen, Denmark; Zilber, a Canadian, is in charge of the restaurant’s fermentation lab.

As you’d expect from a chef whose name is practically synonymous with foraging, Redzepi isn’t the type to call the nearest restaurant supplier when he needs ingredients. In the introduction, he writes, “In the very early years of Noma, we were caught up in a search for ingredients, looking to stock our larder with things that could keep our cooking interesting through the colder months of the year.”

They began to experiment with ways to preserve ingredients, starting with ramson buds. “If you’d asked us what we thought was happening to the tiny garlicky orbs as they sat in a jar packed with salt, we would have described it as ‘curing’ or ‘maturing’. If you’d mentioned the concept of lactic acid fermentation, we would have cocked our heads and looked at you quizzically.

“The ramson capers were a revelation. Suddenly we had this ingredient at our disposal that could bring little bursts of acidity and saltiness and pungency to any dish. And we didn’t have to import it [...] It had grown in our own backyard and become something more, merely through the addition of salt.”

They didn’t realise that this was the start of something big. “I regret not taking more notes in those early days. Every week held a revelation of some sort, reached by the same basic train of thought: We need more things to cook with. We have these seasonal ingredients. What can we do to make them better? What can we do to make them last? At first, we had no idea how fermentation worked […] But year by year, as more ideas worked out and more smart people came into our orbit, we learned how to talk about what we were doing, and began to see the larger tradition we were part of.”

The book is not for those in search of a foolproof recipe for, say, kimchi or sauer­kraut. But you will find plenty of information to use in your own fermentation experi­ments, including backslopping (“the idea is basically to give the substance you intend to ferment a boost of beneficial microbes by adding a dose from a previous batch of that same ferment”) and how to build a fermentation chamber to control temperature and humidity.

Film review – Noma: My Perfect Storm is food porn for gastro-nerds

The chapters include lacto-fermented fruit and vegetables (lacto mango-scented honey; lacto green gooseberries); various types of kombucha; vinegars (black garlic balsamic; whiskey); miso, peaso (using the same technique as when making miso, but substituting peas), ryeso (using rye bread); and shoyu (soy sauce).