The fire, which broke out last Thursday night, gutted one of the factory’s two cookrooms where the crisps are fried, said a spokeswoman.
“We are still assessing the damage, but should be back up and running from the other cookroom shortly.
“It is too early to say when the other one will be operational again.”
In the meantime, there was still several days’ stock held at a separate facility, she added.
Customers were being updated regularly on the supply position, she added.