Ted Smith isn't sure if it's the rich red soil, Robertson's sub-alpine climate or just a little bit of magic in the Illawarra escarpment air that makes his truffle farm so successful - but whatever the secret, it's working.
Late last week, Mr Smith and his wife Barbara unearthed the largest truffle grown in Australia from their Yelverton Truffles property.
Weighing in at 1.172 kilograms, the black Perigord truffle is just 128 grams shy of the world record - a 1.3 kilogram truffle grown in France.
The Smiths have been harvesting from their truffle-inoculated oaks for the past three years, but said the giant specimen was almost double the size of others they have grown.
It was so big it broke their domestic scales, so they had to lug it to Robertson Post Office to be weighed.
"We've had quite a few large ones lately - about 600 grams or so - and I was expecting this one to be quite big too, so at first I didn't get too excited," Mr Smith said.
"It was only when our one-kilo scales wouldn't register that it set off an alarm.
"There was much excitement at the post office, and then we had it verified that we'd broken the Australian record."
Despite widespread interest in the valuable find - which extended to a potential buyer in Asia - Mr Smith decided to sell it locally, to Bowral's Centennial Vineyards Restaurant owner Robin Murray.
Neither man would disclose exactly how much was paid for the huge fungi, with Mr Murray only saying it was "more than $2000 and less than $3000".
The Scottish chef could barely contain his excitement as it was handed over on Monday afternoon.
"It's fantastic, not only for truffle growers in Australia - because the French like to think they're masters of it all - but also for the region here in the Southern Highlands," Mr Murray said.
He planned to use the fresh truffle liberally – making dishes like fresh truffle pasta, butter, scrambled eggs and risotto – and preserve its heady aroma by infusing honey, salt, rice, flour, eggs and master stock for use in the coming months.
He will also let customers and other chefs buy a little piece of the fresh truffle.
‘‘A local can come and buy a gram of it if they want, I’ll shave it onto the scale and they can take as much as they want,’’ he said.
‘‘I’m feeling like a truffle drug dealer here!’’