The Otago Daily Times has been told the smoke may have come from tyres being burned but this could not be confirmed yesterday.
The Otago Regional Council has not received any formal complaints regarding the smoke.
ORC compliance manager Martin King said the burning of tyres or any rubber was not allowed under any circumstances.
Burning waste oil or any other fuel burning equipment in a frost pot was a discretionary activity, which required resource consent from the council.
Jones Family Orchard manager Michael Jones said he was flying helicopters over his Ripponvale orchards last Friday night, and when day broke he noticed a thick drift of black smoke.
The smoke was more than what might have been produced from discretionary methods of frost fighting such as burning frost pots.
"You can tell when an orchard is burning diesel and they certainly don't create that much smoke. Whatever was used was not a diesel burner," he said.
Some Central Otago winegrowers lost about 5% of their crop to frost on Saturday morning, but hope a good flowering on vines will compensate.
Quartz Reef Wines owner Rudi Bauer, of Cromwell, said his vines at Bendigo were hit with the worst frost all year, although damage was minimal.
"If you get a good flowering, which is still possible, then we could have a great season. It is the flowering which determines how much yield you get from the crop," he said.
Across the valley at Bannockburn, Felton Road vineyard experienced a minute amount of damage.
Bannockburn's Carrick Winery and Restaurant viticulturist Blair Deaker said staff spent last Wednesday, Thursday, and Friday nights frost fighting, although hardly any damage was recorded.
Frosty temperatures did not affect fruit at Earnscleugh or Alexandra.
