Mechanical failure in one of the furnaces has been blamed for the fire, which led to hundreds of workers being evacuated and one treated in hospital for smoke inhalation. Firefighters spent three hours tackling the blaze.
Molten glass spilled out of the furnace, and will now have to be painstakingly chipped away while technicians assess the scale of the damage. Two of the five furnaces are currently out of action.
Gallo produces 2.5 million bottles a day at the Modesto plant, for its own products as well as other producers. The facility is said to be the biggest single-site bottle-producing plant in the world, but has a history of problems: two fires broke out in 2008, injuring four people, and in 2006 there was a molten glass spillage.