The 2012 New Zealand grape harvest is down 18 per cent on last year due to a cool spring and summer.
About 269,000 tonnes of grapes were harvested in the 2012 season, down from the record 2011 harvest of 328,000 tonnes, New Zealand Wine Growers said after completing its vintage survey.
The 2012 harvest was expected to be smaller than last year, said Philip Gregan, chief executive of New Zealand Winegrowers.
"The 2012 vintage is very similar in size to 2010, but given sales growth in the past two years, the reduced crop will introduce a new tension to the sectors' supply demand balance," Mr Gregan said.
Earlier wine growers had said one of the worst summers in decades had threatened the harvest in some regions as the grapes were slow to ripen.
Mr Gregan said that while the earlier spring and summer was cool, April was a critical turning point for the vintage.
"Going into harvest the concern among growers and wineries was whether autumn would deliver the weather the grapes needed to ripen fully.
"Fortunately in most of our growing regions April saw excellent vintage conditions with many warm dry days and cool nights."
An over-supply of grapes in recent years has been a problem for the industry and wine exporters have also suffered from the impact of a high New Zealand dollar.
Listed wine company Delegat's Group said in its 2011 annual report that the record 2011 vintage was likely to result in the industry supply imbalance prevailing for at least another two years.
"The supply imbalance has manifested itself in high levels of discounting and the rapid growth
of low price bulk wine exports to 4.8 million cases, accounting for 28 per cent of industry exports by volume," the company said.