Fire response teams from across the region descended on Masterton company Breadcraft on Saturday after a freezer unit caught fire, with crews "prepared for the worst" with highly flammable materials on site.
Masterton Fire Station officer Doug Flowerday said seven fire crews - consisting of five Wairarapa crews and two specialist crews from the Hutt Valley - responded to the call-out to the artisan bread company on Pragnell St just before 1pm.
The fire is thought to have been caused by an electrical fault behind one of the commercial freezers at the plant.
The freezer was "smouldering" when fire crews arrived and was put out quickly, according to Mr Flowerday.
As it stands the damage was contained to the freezer unit and its contents but Mr Flowerday said it could have been much worse.
"It had the potential to be a very large fire."
"The polystyrene panels at the back of the freezer unit could have caused it to spread much further which is why we were prepared for the worst."
He said the polystyrene catching fire had created a lot of smoke and the specialist breathing apparatus and command team took some time to ventilate the building after the fire was contained.
Breadcraft director Peter Rewi said he was "extremely grateful" that firefighters responded so quickly after smoke coming from the plant was noticed by a neighbouring business.
"It could have been so much worse. The firefighters were amazing.
"They were prepared for the worst and did a brilliant job in the end."
Breadcraft managers, including Mr Rewi, had come down to the scene of the blaze on Saturday afternoon to show firefighters the wiring and set-up of the freezers once the blaze was put out.
Mr Rewi said Breadcraft was "very lucky" that no one was working or inside the plant at the time of the fire. I'm very thankful no one was there and no one was hurt."
Breadcraft will have a better idea of the cost of the damage in the next few days.
The products inside the freezer were destroyed in the blaze and the freezer itself will require significant repairs or will need to be replaced.