One staff member has suffered burns after a blaze gutted a winery's storage facility on the Mornington Peninsula, south of Melbourne.

The facility adjoining the restaurant and cellar door at the Ten Minutes By Tractor winery at Main Ridge was engulfed in flames at 3:30pm on Sunday, sending thick smoke across the area.

The facility, an old apple shed containing vintage trucks and wine as well as stock, was gutted by the fire.

Twelve trucks fought the fire, with the shed fully engulfed when crews arrived. Gas cannisters were exploding, and it took two hours for firefighters to control the blaze.

Forty diners and staff evacuated the facility, but a chef suffered burns to the face and arms.

Restaurant owner Martin Spedding estimated about half a million dollars worth of wine had been destroyed.

"It's quite devastating what we've lost inside the shed but it's not going to impact on the business in any bad way," he said.

"We should be able to reopen again hopefully in a reasonable time frame."

The Country Fire Authority's Darrel Setter said the cause of the fire is unknown at this stage.

"The smoke was billowing high in the air and flames were probably 20 or 30 feet high," he said.

"We just could not bring it under control. In the end it just burnt itself."

Kitchen worker Colleen Lewis said restaurant chefs lost a lot of possessions.

"We both raced out into the back room where the fire was happening and everything was just red with flames. It was really devastating," she said.

"We lost our car keys. We lost our house keys but everyone's alive, everyone's fine. One of the chefs got burnt on the face and arm but he's fine.

"All we were more worried about was lives being saved and once we got everybody out we were fine with that."

"It escalated quite quickly," restaurant patron Dorinda Mercier said.

"It was, by the look of it, quite an old building that contained a lot of documentation, wine, olive oil and that, so all their stock, there was a lot of vintage wines stored there. It was quite a high-end restaurant."