Some wine producers in flood-ravaged Tairāwhiti and Hawke's Bay may resort to picking grapes by hand - rather than using mechanical harvesters.
Cyclone Gabrielle resulted in tonnes of silt and mud being deposited across horticultural and pastoral land two weeks ago, just as the harvest was on the cusp of starting.
NZ Winegrowers chief executive Philip Gregan said some growers would not be able to get heavy gear onto the land so manual labour would be needed to get grapes into wineries in the best possible condition.
Growers were looking at whether they could get hand-harvesting crews into vineyards. "That enables them to be quite selective about the grapes they pick, that's one advantage of hand harvesting," he said.
Gregan did not know whether there were enough people around to do the work.
But he said growers were certainly looking around for labour.
Hawke's Bay and Gisborne produce 12 percent of New Zealand's wine between them, and Gregan said it was still not possible to say how much crop would be written off.
"Those growers who have silting and flooding, it is still difficult to work out actual numbers, what percentage of the industry, but it is by no means the majority, so we are still expecting significant vintages out of both regions at this stage," he said.
Some flood hit grapes could be harvested, unlike apples and kiwifruit which could not be picked for health safety reasons.
"We're dealing with a processed product, so it goes through fermentation and it has alcohol as wine, and pH levels, these all make wine very microbiologically safe as a product.
"We are more worried about chemical or physical contamination."