“Culture is not cooked, it is lived, and cooking is the expression of culture,” Rafa Costa e Silva, head chef of La Sai restaurant, Rio de Janeiro, commented at Gastronomica 2025, one of the most important events in the world of food. Sustainability, once a symbol of conscious cuisine, no longer carries the weight of the culinary future. The mission has become bolder: to restore what the world has already lost. Chefs are moving beyond the kitchen, taking on roles as architects of heritage and caretakers of ecosystems as they navigate a planet marked by climate upheaval, vanishing biodiversity and fading traditions.
At the 27th edition of Gastronomica, held from October 6 to 8, 2025, at the Kursaal Congress Center in San Sebastian, Spain, the ocean took center stage, as chefs and researchers alike celebrated “super blue foods” – algae, seaweed and other often overlooked marine species that are nutrient-rich and environmentally gentle. Unlike traditional land-based agriculture, which drains soils and pollutes freshwater with chemical inputs, thoughtfully grown seafood can restore ecosystems, improve water quality and even sequester carbon, offering a blueprint for regenerative nutrition from the ocean.
Fourth-generation seaweed grower Takashi Okui shares the most compelling case study. His family’s company, founded in 1871, has specialized in kombu seaweed for 154 years, and has hosted culinary experts such as Pascal Barbot, René Redzepi and Alain Ducasse. Okui presented kombu as a complete regenerative system. His company uses a technology called kuragakoi Which involves aging kombu for years, sometimes decades, in carefully controlled warehouses. Some of his lists date back to 1889. This extended maturation develops unique flavor compounds, including five special components and elevated glutamic acid not found in fresh kombu.
The parallel to the aging of the wine is intentional. Kyoto chefs call to request specific vintages: 10-year-old kombu, 15-year-old kombu, matching the character of the ingredients to their culinary vision. Hideki Matsuhisa, chef of Barcelona’s Koy Shunka, emphasized the educational challenge: More than 3,000 Japanese restaurants exist in Spain, but most do not make authentic dashi broth. Instead, they rely on instant powder concentrate. The convenience makes sense, but the difference between powdered and properly prepared kombu-katsuobushi dashi is substantial. Its implications extend far beyond Japan. Coastal areas from Kerala to Norway have dramatically different marine ecosystems that remain unexploited and seaweed cultivation remains marginal in most places. If it is practiced, it is primarily for industrial extraction, not for human consumption.
What’s missing is the cultural infrastructure: training, markets, culinary traditions that make these ingredients desirable rather than simply available. Norwegian chef-fisherman-diver Roderick Sloane has pioneered kelp farming in Scandinavian waters, while previously documenting stock recovery in overfished areas, demonstrating that kelp farming can support rather than degrade marine ecosystems. Gastronomica’s agricultural discussions also revealed how deeply regenerative thinking had penetrated European farming, particularly in the Basque region.
Chef Rafa Costa e Silva’s Lasai restaurant maintains a 10,000-square-metre kitchen garden in the mountains, 90 minutes from Rio, which works on a basic principle.
He says, “The product always comes before the menu. We’ve never had a defined menu, which makes no sense to me. Maybe you’re making a turnip dish, but there are no turnips this week. So, what do you do?” This philosophy, revolutionary in its simplicity, overturns traditional restaurant logic. Rather than designing dishes and then gathering ingredients to execute them, Costa e Silva builds his menu based on what the garden provides at peak quality. The Basque Country itself has become Europe’s regenerative agriculture laboratory. Its topography, steep hills, abundant rainfall and relatively small land mass have never been conducive to industrial monoculture. When the wider European agricultural sector adopted mechanization and chemicals in the post-war decades, Basque farmers maintained more diverse, smaller-scale operations out of necessity. Practices include reducing tillage to preserve soil structure, maintaining permanent plant cover to prevent erosion, integrating livestock to cycle nutrients, and actively building organic matter content through composting.
Chef Alejandro Ibáñez of Barahonda in Yecla highlighted the economic dimension. Operating in a winery area, his restaurant focuses on waste reduction, “We’re obsessed with not wasting anything. If we’re using seasonal ingredients, so much the better, because it’s cheaper, but that’s also when it’s at its best.” Ibanez works extensively with wine lees, the yeast sediment typically left over after fermentation, transforming this waste product into an ingredient that adds acidity, complexity, and umami to many dishes. This is regenerative thinking that applies to food systems rather than just farms.
Wine lees, “acidic, with brioche, yeast notes too” add a note of complexity to many of the dishes we cook, he said. Ibáñez also uses potato peels, eel bones and skins, and fig clippings that would otherwise be discarded. But regeneration requires patience and capital that most farmers and fishermen lack.
The most promising models combine tourism and education, premium pricing for regenerative products, and ecosystem service payments that compensate farmers and fishermen for carbon sequestration, water quality improvements, and biodiversity support. Many chefs have become direct investors in regenerative supply chains. Mitsuharu Tsumura of Maido in Lima has funded reforestation projects in the Peruvian Amazon, as well as sourcing indigenous materials that have commercial value only when the forest ecosystem remains intact. Oriol Castro of Disfrutar in Barcelona supports small-scale fishermen practicing selective techniques that preserve marine breeding populations.
Gastronomica 2025 also emphasized the recovery of culinary knowledge erased by industrialization and globalization. Chef Viviana Varese exemplifies this dimension. Working at the 18th-century Villa Passalacqua on Lake Como, home of the composer Vincenzo Bellini, Varese conducted extensive anthropological research into historical cuisine. They learned that Queen Caterina de Medici of France introduced many basic elements into French dining etiquette and cuisine, including the fork, the fragrant tablecloth, separating sweet and savory dishes, and dishes ranging from broccoli and onion soup to macarons and eclairs. Veres believes that “by the 1700s, cuisine had become greatly globalized” as cooks traveled throughout Europe, incorporating ingredients from India, the Americas, and Russia. These included spices, potatoes, tomatoes, chocolate, creating a culinary exchange network that was more sophisticated than many anticipated. Their menu revives these historical preparations, not as museum pieces but as vibrant dishes adapted to contemporary technique and expectations.
This may not be obvious but the parallel to endangered foods around the world is direct. Paolo Loureiro’s demonstration of dried octopus soup is an example of this. This dish, which has “not just gastronomical value, but additional historical value,” was traditionally served on the Basque coast from Zumaia to Mutriku, but is now rarely prepared, “mainly for sanitary reasons,” Loureiro said. “It’s a pity, but it is lost. I don’t think it is served anywhere anymore. It is the older people who cook this recipe at home.” This dish is culturally significant, but potentially dangerous according to modern food safety standards, a reminder, perhaps, that not all traditional preparations are worth revival without adaptation.
Vedehi Geete is an independent journalist.
