Farm grows mushrooms using spent coffee grounds

Roy Cox, managing director for Estates at Blenheim Palace, said it was "incredible" to see mushrooms grown using the estate's own organic waste

What are thought to be the first gourmet mushrooms grown from coffee grounds have been harvested.

Lion's Mane, blue-grey, golden, and pink oyster mushrooms have been grown on a surface created from sawdust and recycled coffee grounds from the 440,000 cups of coffee sold every year at Blenheim Palace in Woodstock, Oxfordshire.

When running at full capacity, the farm based in Combe, will be sending 15kg a week to the Palace kitchens.

The remaining 85kg of its produce will be distributed through the non-profit group OxFarmToFork, farmers' markets and to local pubs and restaurants.

The farm consists of three units for preparation of the substrate and its inoculation with mushroom spawn, incubation and fruiting.

It is the latest stage in the Blenheim's collaboration with circular bioeconomy company Tumblebug.

The project unlocks the value of Blenheim's organic waste, such as food, coffee and sheep wool.

Once harvested, the spent substrate from the mushroom growing is converted to biochar compost.

Combining biochar, substrate, sheep wool, horse manure and green waste from the gardens the Estate's organic resources are used to enrich its soil.

The compost is then used in the Palace's walled garden to grow more produce.

Lion's Mane and golden King Oyster mushrooms are some of the types grown from sawdust and the recycled coffee grounds from the 440,000 cups of coffee sold every year at Blenheim Palace

Roy Cox, managing director for estates at Blenheim Palace, said it was "incredible" to see mushrooms grown using its own organic waste.

"The mushroom harvest is the final piece of the puzzle, which completes this self-sustaining circular ecosystem," he said.

It received a five-star food safety hygiene rating from West Oxfordshire District Council.

When running at full capacity, the farm will be selling 85kg of its produce through local farmers' markets and the OxFarmToFork project