Wine producer Delegat's Group says it has harvested 28,884 tonnes of grapes in the 2013 vintage, an improvement of 42% on last season.
The company says the harvest has delivered on target yields and ideal weather conditions have produced a fruit of exceptional quality.
Managing director Jim Delegat says the grape growth was good at the company's vineyards in both the North and South islands.
Mr Delegat says the improved harvest has allowed the company to rebuild its depleted inventories.
"We do need this increased productivity because we have been running very, very low inventories, so our chardonnay, pinot noir and merlot inventories, which require some age in barrel and extra maturing time, have been run at very low levels."
He says strong international demand for Marlborough sauvignon blanc is helping to strengthen the New Zealand wine industry as a whole.