Scientists cultivate black truffle on Isle of Bute in potential UK island first

Researchers on the Isle of Bute have reported the cultivation of a black truffle species commonly known as the burgundy or summer truffle (Tuber aestivum), a find they say may be the first recorded cultivated truffle on a UK island.

The 4.45-gram specimen was discovered on July 30 by Professor Paul W. Thomas, an honorary professor at the University of Stirling and founder of Mycorrhizal Systems Ltd, who had planted a small hedge of hazel trees inoculated with truffle fungus five years earlier. Professor Thomas said he found the truffle without the help of a dog after signs of animal activity revealed the fungus material breaking the soil surface; larger and riper truffles are expected to be located in the coming weeks with the aid of Rue, a trained truffle dog.

The cultivated species, Tuber aestivum, is prized in gastronomy and can sell for up to £900 per kilogram. The truffle on Bute was grown using techniques Professor Thomas has developed over more than two decades and is now being advanced in conjunction with Professor Alistair Jump, dean of the Faculty of Natural Sciences at the University of Stirling.

Their collaborative work, published in 2023, examined the potential of tree–fungus systems to deliver both food and environmental benefits. The study estimated that planting fungi with host trees to produce edible mycorrhizal mushrooms could sequester up to 3.5 tonnes of carbon per hectare annually and, when scaled, provide a nutritious food source for millions. Researchers have described the cultivation system as low-input, requiring no irrigation, chemical treatments or fertiliser because tree roots form a symbiotic relationship with the fungi.

Professor Jump said the discovery on Bute strengthens arguments for regenerative land uses in coastal and island locations. "Truffle orchards are long-term, low-maintenance systems that support biodiversity and soil health while offering economic return," he said. Professor Thomas said the development could create new options for land use, economic development and tourism in coastal and rural areas, describing the find as "a landmark moment — not just for science, but for the future of land use in the UK."

Scientists working on the project emphasised that truffle cultivation is a long-term endeavour. Establishing productive truffle-bearing stands typically takes several years from initial inoculation, and yields can increase as trees mature and fungal networks become established. The Bute discovery follows the five-year timeline of the hazel hedge planted and inoculated in Professor Thomas's garden.

Truffles are commonly associated with Mediterranean climates and are traditionally harvested in countries such as Spain and Italy. Researchers say certain species, including Tuber aestivum, can thrive in a wider range of temperate conditions, which has encouraged experimental planting in parts of the United Kingdom and other northern regions.

The research team has framed the project within wider policy debates about sustainable and climate-resilient agriculture. They argue that mycorrhizal cultivation systems could offer diversified income streams for landowners and island communities, and that the low-maintenance nature of these systems may make them particularly suited to marginal or remote landscapes.

Independent experts caution that while the Bute truffle is notable, broader uptake will depend on reproducible yields, market development and support for growers. Truffle orchards require monitoring and time for fungal networks to mature, and commercial viability can vary by species, soil conditions and management practices. The researchers acknowledge these constraints and say further monitoring and trials are planned to document productivity and ecological effects across sites.

The team on Bute intends to continue harvesting and monitoring the site and to expand trials to better understand the ecological and economic potential of truffle cultivation in Scotland. Their work aims to provide data on yield trajectories, soil carbon changes and biodiversity impacts to inform future land-use decisions on islands and coastal regions.