As one of the world's most revered gourmet foods, some truffles can sell for more than €1,000 per kilogram, making cultivation a lucrative business. However, the industry remains unpredictable, with some trees capable of producing a valuable harvest—while others that are seemingly similar are not. New research from the University of Stirling has revealed that growing truffles depends not just on soil conditions, but on a complex underground ecosystem that the truffles may help engineer themselves.