(ABC) - The wine grape harvest is underway in the Upper Hunter with Two Rivers at Denman reporting a positive start to picking.

Sparkling grapes have been first off the vines, while a test run of the company's whites has returned good results.

James Estate at Baerami expects harvesting of its crop will commence this weekend.

Brett Keeping from Two Rivers said after a challenging growing season, December rainfall has filled out the fruit.

"Surprisingly the tonnages look to be well up," he said.

"It's early days and we've only gone into a couple of blocks, but after the spring we had we were all expecting the berry size to be small and our bunch counts were actually down a bit on last year, but the crops seem to holding up well.

"I think that last rain we've had has filled things out nicely.

"Hopefully it's early enough in the season, if it dries up now we should get a clear run."

Mr Keeping said a run of dry weather will ensure a flavoursome crop.

"The first comments from when we started sampling from all the winemakers was, 'wow, there's lots of flavour this year'," he said.

"Which is a great sign, it means we can actually get in a bit earlier.

"If those flavours do come in and start accumulating early in the berries, that's a really positive thing for us.