People may think of a chocolate treat when they hear the word truffle. Georgie Patterson grows a different type of truffle on her Trentham farm and she trains dogs to sniff them out.

A truffle is an edible underground fungus which grows in a symbiotic relationship with certain tree roots.

Georgie grows four different varieties of truffles on her Trentham property - the Perigord black truffle (tuber melanosporum), summer or burgundy truffle (tuber aestivum), small Italian white truffle (tuber borchii) and some of the large Italian white truffle (tuber magnatum).

"We've got some tuber magnatum in, which is the most expensive truffle in the world."

It's a high end product.

Chefs use truffle shavings in a variety of dishes such as pastas, soups, eggs and potatoes.

Georgie says the most common truffle - the tuber melanosporum - will cost about $2,000 per kilogram when it comes into season shortly.

"Your trees start off producing a minimal amount, and that really depends on the area.

"It is an expensive crop to grow, and it depends a lot on the soil science and there's still a lot we don't know about it."

She says truffle growing is becoming more common around the region.

"I think this region will become... a region that's known for its truffle."

Truffle harvesting involves recognising the truffle scent and identifying whether or not the fungus is ripe enough to pick.

Georgie uses dogs to sniff out the truffles.

"You want the dog to fairly much pinpoint where the truffle perfume is, you could do it yourself if you wanted to get around on your hands and knees but it's much easier with a dog."

Payment of a small meaty treat is enough incentive for these working dogs.

Georgie is running demonstrations as part of the Daylesford Macedon Produce Harvest Week Festival.