The success of the season still hangs in the balance, with the heatwave threatening to derail what was expected to be a bumper year.

Chris Pfeiffer, senior winemaker at Pfeiffer Wines and chairman of the Victorian Wine Industry Association, said conditions to January had been the best the North East had seen in 10 years.

“Everything was lining up for what I would have considered to be one of the great years,” he said.

“I had my fingers crossed — you don’t get great years very often.”

But Mr Pfeiffer said the scorching temperatures could play havoc with the fruit if left unchecked.

“You just have to watch your sugar levels in the grapes because they can bolt in this sort of weather,” he said.

“You can get massive increases of sugar in a very short period of time.

“I’ve never picked grapes in Rutherglen in January before, I’ve never ever picked them this early.”

Mr Pfeiffer said winemakers were now engaged in a balancing act, needing to give the grapes time to reach optimal flavour without allowing them to spoil in the heat.

“If this hot weather keeps going, unfortunately we’ll just end up with an average season,” he said.

“But in today’s environment, we’ve got to make every post a winner because there’s surplus wine out there.

“To sell it you need to actually be up there in the quality stakes.”

Rutherglen Estates viticulturalist Matt Partridge said his team of nine had started picking at 3am yesterday, the same date the winery’s harvest began last year.

Grapes for white wines will be picked again tomorrow, with reds being left on the vine until the second week of February.

“The remainder of the vintage will actually be moved forward because of the hot weather,” Mr Partridge said.

“We’ll just have to wait and see. It’s just a matter of holding on.

“If we can use our water properly, we should be able to get through.”