You may have heard earlier this week that the world’s largest truffle (at 3.3 pounds) sold at auction for $330,000—the largest sum ever paid for a single specimen of the rarified fungal delicacy. The auction, which was held simultaneously in London, Florence and Macau, was won by Macau casino magnate Stanley Ho, who outbid luxo-artist Damien Hirst (of multi-million-dollar diamond skull fame), among others. Ho’s plans for the ‘shroom are still unknown.

If you’re quick on your feet, you’ve probably already put that into supermarket terms—an astronomical $100,000 per pound. While the hype value of the “world’s largest” aspect of this auction inflated the price significantly, even at normal market price, truffles are among the most expensive food items on the planet. Why?

Because just about every truffle that lands on your plate has to be not picked but found—underground, mind you—by a human being, usually with the help of a specially trained mushroom-sniffing dog. All species of truffle (in the Tuber genus) are ectomycorrhizal, meaning they require a symbiotic relationship with roots of specific trees to live. The truffles, sprouting underground attached to the roots, get easy access to the nourishing sugars created by the tree during photosynthesis. The tree gets the benefit of increased root surface area with which water and nutrients can be better absorbed.

While it is possible to manually inoculate the roots of young trees with certain species of Tuber fungi, theoretically turning said tree into a truffle factory, the symbiotic relationship relies on numerous variables to thrive, including the presence of other fungi, soil and weather conditions, and specific types of trees. Add to that lag times of up to 20 years before truffles begin to sprout if you’re lucky enough to get them to grow at all, and you’ve got one impossibly finicky plant to cultivate. It hasn’t stopped humans from trying ever since the first proto-gourmand went ga-ga over the rich, earthy goodness of truffles hundreds of years ago. But there’s still quite a long way to go. —John Mahoney