The largest and most destructive of the wildfires in California has grown to 140 square miles and fire officials have said the worst may be yet to come.

The 90,000-acre fire burning in Ventura County, northwest of Los Angeles, has swept ridges and canyons to the sea and the winds that drove it are expected to return with a vengeance overnight.

State fire director Ken Pimlott said winds that eased on Wednesday could return with gusts up to 80mph yesterday that would make it impossible to fight the fire.

Dozens of homes have burned since the blaze erupted on Monday. Nearly 1,800 firefighters and a fleet of aircraft are fighting the flames but the blaze is only five per cent contained and an estimated 12,000 buildings are in danger.

Earlier a wildfire in a wealthy western area of Los Angeles reached an estate and winery owned by media mogul Rupert Murdoch.

Roxanne Langer at Moraga Vineyards in Bel Air said a temperature-controlled wine storage shed burned after the fire erupted before dawn, but it was unclear how much wine was lost.

She said firefighters stepped in to douse the flames with the aid of helicopters and that other storage sheds, the winery itself and the estate’s unoccupied house are not damaged.

The winery, bought by Mr Murdoch for about $30 million in 2013, has been evacuated.

Ms Langer said it appeared the seven acres of vines suffered only slight damage and the grapes already had been harvested.