Wine growers are being advised to curb their production again or risk further eroding their profitability.
The latest report on the industry, by Deloitte and New Zealand Winegrowers, says next year's grape harvest could exceed 300,000 tonnes, up more than 30,000 tonnes on this year.
New Zealand Winegrowers' chief executive Philip Gregan says there is market for only 265,000 tonnes of grapes and an oversupply will further erode grape and wine prices.
Mr Gregan says the financial hardship will continue in the industry for at least another year, with more vineyard and winery receiverships likely.