About nine cubic metres of garlic bread have been destroyed in a fire which burnt for several hours at a factory at Capalaba, south of Brisbane.

The blaze ignited in the cold room of the Australian Garlic Bread Company about 2:00am, taking 45 firefighters to bring it under control.

Queensland Fire and Emergency Service Area Commander Inspector Simon Evans said the building was heavily smoke logged, which initially slowed efforts to find the source of the fire.

"We've got a large amount of product, which is garlic bread in aluminium foil wrapping that's inside boxes," he said.

"That's collapsed into a great big pile, and at the moment firefighters are using hand tools, shovels, pulling the product out, wetting it down and trying to get to the seat of the actual fire.

"It's a particularly difficult job because we're working inside a cold room.

"It's obviously not cold in there at the moment, but it's confined.

"It's difficult to see, and because the product has collapsed, and obviously cardboard boxes when they get wet, they collapse, it's ended up in a great big pile on the floor."

About nine cubic metres of garlic bread has been destroyed, four in the fire and five in the boxes that got wet.

Inspector Evans said surrounding properties were not threatened and there were no injuries.

"No-one was hurt, and it was fortunate the factory had a brigade alarm so we were notified and were able to get onto it really quickly," he said.

He said once the source of the fire was found and stemmed, he expected the factory could start operating again.