Niklas Ekstedt was on holiday with his family at their summer home on the island of Ingarö. As is the Swedish custom, he gathered birch wood and built a fire pit in preparation for a summer of outdoor cooking. But one day, too impatient to wait for the logs to heat sufficiently, he thrust a cast-iron pan into the flames and cooked his fish. “It tasted amazing,” he recalls.
An idea started to form. Ekstedt was already a successful chef and tv personality in Sweden – along with René Redzepi of Noma in Copenhagen and Magnus Nilsson of Fäviken, he was one of the young chefs redefining the Nordic culinary identity. He was due to open a new restaurant in Stockholm that autumn, but he’d been struggling to think of a fresh approach.
In fire he found his identity. “Cooking over wood is part of Swedish life. Even when we go hunting in the winter we breakfast outside over an open fire and every family has its own special smoker,” he says. His restaurant would rely solely on cooking with wood – on the open flame, in embers, with smoke and ash.
“I realised that, following El Bulli in Spain and Noma in Copenhagen, chefs were using less and less heat in their cooking,” Ekstedt explains. “Techniques such as sous vide cook food at very low temperatures and chefs were using warm oils and delicate raw ingredients to complement it.” Cooking with fire was the opposite.
It was not exactly a new idea. Palaeontologists suspect that Homo erectus was the first hominid to control fire; it is generally accepted that the charred animal bones found in Swartkrans in South Africa, dating between 1m and 1.5m years ago, were cooked. Crucially, cooking with fire allowed Homo erectus to eat and digest tough vegetables and meat, which may have led to the development of our much smaller chewing muscles. Certainly, it later helped Neanderthals and Homo sapiens to adapt to a changeable and harsh climate.
In November 2011, Ekstedt opened his eponymous restaurant to a bemused public. The general view was that a restaurant using fire must serve steak. Instead, customers stepped into a simple room, infused with the smell of the wilderness: birch-wood fires and juniper smoke. Ekstedt’s team sizzled langoustine in cast-iron pans directly over the flames of a fire pit, gently caramelised vegetables on a traditional cast-iron wood-fired stove and smoked bone marrow and tomatoes in its specially designed chimney. Ekstedt built a box-shaped Swedish wood-oven that relied on the stone floor for heat conduction to bake crusty rye bread and knäckebröd – crisp rye biscuits. An ember-filled smoking box soon followed.
“We needed to understand the techniques before we could develop a recipe. Small delicate ingredients that are popular in new Nordic cooking simply disappeared when they were subjected to the extreme heat of our cooking. I needed rougher, bigger things, so I have to order the biggest carrots my supplier can find,” explains Ekstedt. He delved into old cookbooks and watched how the Sami cook with fire. They often add acid to the food in their cast-iron pans, something he had been taught not to do, as it reacts with the metal. “But it really intensifies the flavour of the dish. It takes a while to get used to cooking with fire – but once you do, you don’t want to go back to normal cooking. Cast-iron pans imbue food with a deeper taste – a mixture of fire, treacle and chocolate.”
Bite into Ekstedt’s intensely fresh-tasting blackened leek, served with vendace (a relative of the salmon) roe and charcoal-smoked cream, and you find yourself transported to the countryside. The subtle combination of verdant greens and smoky charred notes sends tingles through your tongue and recalls that sense of excitement you get standing around a barbecue or fire pit.
For the chef, part of the challenge lies in having constantly to react to the changing behaviour of fire. The flames heat their surroundings through convection. With cooler fires, partial combustion of wood generates chemicals that can alter the flavour of ingredients: at around 200˚C/390˚F, wood releases aromatic carbonyls that react with the amino acids and sugars in food to change its colour and generate that smoky flavour; above 300˚C/570˚F the lignin in the wood breaks down to release a range of volatile chemicals. These all have distinctive aromas, reminiscent of flavours such as cloves, caramel or peat, which infuse the food.
Ekstedt aside, in Europe wood-fire cooking is predominantly a Spanish skill, perfected in restaurants such as Asador Etxebarri in Atxondo. In the Americas, though, it has been growing in popularity over the past decade, led by Dan Barber’s griddling and baking on a specially adapted Argentine-style wood-burning grill at Blue Hill at Stone Barns outside New York; and Francis Mallmann, the acknowledged grandfather of new-style fire-cooking, whose books “Seven Fires” and “Mallmann on Fire” have changed the way chefs think about this most ancient of culinary techniques. Most recently, respected chefs like Michael Chiarello (Coqueta in San Francisco) and Danny Meyer (Marta in Manhattan) have introduced wood-burning grills to their restaurants.
Over the years, Mallmann, an elegant, cultured man with a soft voice and shock of grey hair, has developed numerous methods of cooking with fire – both indoors and out. “It’s incredible, even now I feel as though I am just starting to develop new ways of thinking about fire and cooking with it,” he says. He views fire as a magical force. “Fire is fragile and tender. You have to learn how to read all that is fire, from the pit to the ashes. Outside you must read the flames, the wind, the rate of fat dripping and the distances between food and fire.”
He explains that, on a gas griddle, you have an even heat all over so everything cooks in the same way, but with wood, the heat varies across the griddle. While an ordinary bread oven will have maybe three temperatures, in a wood-burning oven there will be 15 different parts – so, as Mallman puts it, “you can caress a little potato on one side and burn a peach on the roof.”
The type of wood needs to be chosen with care. He uses eucalyptus for the griddles and ovens as it has a very good flame, while for the grills he prefers quebracho or coronilla, indigenous heavy woods that are so dense they burn very slowly until they resemble huge red lumps of charcoal.
It’s still early days, but the culinary movement towards a reconnection with nature suggests that Mallmann-inspired dishes such as his succulent five-hour ash-cooked vegetables may well replace the tepid foams and dehydrated, flavoured crumbs found in many restaurants. Mallmann has developed a new system to conserve wood and maximise its heat for his latest restaurant, Los Fuegos, in Miami. Ekstedt, meanwhile, believes that the future for his cooking lies in developing lighter dishes that carry the hint of fire, such as cold-smoked mussels served in their own fragrant juice with salted cucumber and seaweed. It’s a marriage of ancient skills and modern taste, fire and food, nature and civilisation.