New Zealand's grape harvest is 9 per cent down on last year's, mostly due to bad weather, NZ Winegrowers said.
The 2017 Vintage Survey showed the harvest totalled 396,000 tonnes.
"Given strong demand in overseas markets, wineries had been looking forward to a larger harvest this year," NZ Winegrowers chief executive Philip Gregan said.
"With the smaller vintage however, export volume growth is likely to be more muted in the year ahead," he said in a statement.
Generally summer weather was very positive but there were some challenges as the season progressed, Gregan said.