Michelin-starred restaurant bids $170000 top white truffle

White truffles are the world's most expensive ingredient. Photo / Giorgio Perottino, Supplied

An enormous, white truffle weighing 900g has dug up a frenzy of international bids, selling for little over $170,000 at auction.

The top truffle went to buyer Umberto Bombana of Hong Kong where it will become a prize ingredient at the restaurant 8½ Otto e Mezzo.

The massive mushroom auction took place in Piedmont northern Italy, during the international Alba White Truffle Fair. Held at the Castle Grinzane Cavour the prize truffle saw bids from truffle fanciers in Dubai, Singapore and Moscow. The charity sale finally ended in favour of Bombana, last week, paying $188 per gram of truffle.

Large white truffles can fetch hundreds of thousands of dollars at auction. Photo / Supplied, Tartifo Bianco d'Alba

One of the most expensive ingredients in the world, Tuber magnatum Pico is only found in a few parts of southern Europe. Their rarity comes from the difficulty of locating the mushrooms, which grow underground and the fact that - unlike black truffles - they cannot be farmed. They must be rooted out by well-trained truffle hunting dogs or pigs.

White gold: The White truffle cannot be farmed. Photo / Supplied

However the charity auction drove the prices even higher, with proceeds going to the Hong Kong charity Mother's Choice.

Piedmont is visited by around 100,000 mushroom-mad visitors from around the world every year for the autumn festival which finishes on 5 December.

100,000 mushroom mad visitors arrive in Piedmont every Autumn. Photo / Supplied, Tartifo Bianco d'Alba

The annual festival is fuelled by a love for the ingredient which grows naturally in the area, also known for Barolo and Barbaresco wines.

Over $780,000 were raised for charity during this year's festival, according to the organisers.

Top truffle records

The White Alba truffle was a star lot at the auction, however it isn't the largest ever seen by the festival.

In 2007 the largest known white truffle weighing 1.496kg was sold at auction for $474,000 to Stanley Ho, the Casino Mogul from Macau.

That's $316 per gram of mushroom.

The largest ever black truffle, meanwhile, sold at auction weighed 1.887kg and was bought by an anonymous bidder at Southerby's in 2014 for a mere $88,075.