Fungi never tasted this good. At least that’s according to oyster mushroom connoisseurs who have developed a taste for these morsels grown in a unique set: beneath the earth in the dusty caverns of Kimberley’s disused diamond mines.
It is the first time oyster mushrooms have been mined underground for commercial use — and the project has spawned an industry that’s not likely to stop here. Future Barney Barnatos may be in the making, with mushrooms, not diamonds, the route.
Today, nearly two years after the start of Diamond Mushrooms Farms, its products have reached mushroom-lovers based as far afield as Mauritius, Namibia, Botswana and Swaziland — and quite a few local gourmets.
Site manager Peter Jansen relates a favourite anecdote: “A vegetarian doctor orders 5kg of our oyster mushrooms every single week. And, fantastically, he has doubled his time in running marathons. It’s because of the protein contained in these things.”
In comparison to other mushroom species, which have a substantial water base, Jansen says oyster mushrooms contain more than 35%protein and are abundant in minerals.
Oyster mushrooms are so close to the heart — and palate — of academic Albert Eiker that he plunged virtually all of his retirement funds into the company. “Everyone thought we were crazy. But I have been developing and selling mushroom spawn to commercial manufacturers for quite a number of years and I knew that the potential was there.”
Professor of botany at the University of Pretoria and regarded by many mycologists as Africa’s foremost authority on the subject, Eiker says farming ordinary mushrooms in subterranean tunnels is by no means a new development. But mining oyster mushrooms is an entirely different ball game.
They need more light than their button counterparts and a stable, humid climate, which fellow investor Markusllll Reichardt, a 37-year-old environmental manager at AngloGold, discovered in the prime mining conditions of the Big Hole. It was Reichardt’s job to see how redundant infrastructure owned by De Beers could be used efficiently.
“I was tasked with trying to find some kind of attributes that they possessed. Luckily the tunnel I found had just the right conditions” a — complementary combination of the correct temperature, humidity and lighting that was already installed in the mine. Oyster mushrooms are fussy; they refuse to live on compost as other species do. At Diamond Mushrooms they’re grown on a hybrid mix of wheat straw and various mutis, such as lime and gypsum.
The past few months have not been kind to Diamond Mushroom Farms. This year’s bone-dry winter dropped the temperature in the mine to 12C and the mushrooms stopped growing. Meanwhile, the petrol price doubled and trebled. And as if this wasn’t enough, bread mould arrived, growing faster than the mushroom spores.
Then, like an omen, mists of flies appeared like locusts. “There’ve been some tough times,” the professor admits. “Biologically, it was the bread mould and the flies. We couldn’t use insecticide since we were dealing with food. Economically, the petrol was definitely a hindrance to production.”
But he says the company is over the worst of it now — and there’s a whole world of underground farming ahead that could transform the lives of unemployed mineworkers. Eiker also sees a potential for impoverished rural people to farm and harvest their own oyster mushrooms; wheat straw is cheap and available, one must only provide the light and ensure the correct temperature.
And what do you do with oyster mushrooms when you’ve harvested them? Eiker’s favourite is a familiar recipe but just that much better done with oyster mushrooms instead of buttons. “Fry them in a little bit of olive oil,” he says. “Drown them in garlic and sprinkle with lemon juice.” Of course.