Mouse droppings, dirty surfaces, and mould inside bread-making equipment were uncovered by hygiene inspectors during a visit to a bakery.
Owners of Bloomers Bakery Ltd were ordered to pay fines and costs totalling £8,595 when they appeared at Croydon Magistrates Court on Monday.
Derek Carpenter and his wife Emma Carpenter had previously admitted seven charges for offences that took place in June and July 2014.
Croydon Council food safety officers visited the company’s shop in Lower Addiscombe Road, Addiscombe in June 2014.
An inspection of the main bakery premises in Tait Road, Selhurst a few days later revealed evidence of a mouse infestation and dirty conditions in a number of areas.
This led to a voluntary closure notice being served, which required all the prepared food on the premises be thrown away or destroyed.
District Judge Andrew Sweet said he could not stress the seriousness of the mouse infestation at Bloomers Bakery, which also has branches in South Croydon and Redhill.
But he acknowledged the immediate steps taken by the bakery, including pest-proofing, which had allowed the bakery to re-open soon after being served the voluntary closure notice.
On Tuesday Mr Carpenter told the Croydon Guardian he had been suffering from health problems and had been in and out of hospital at the time of the offences, leading him to take his “eye off the ball” at the bakery.
He stressed that the bakery had co-operated fully with the council and introduced new food safety measures.
He said: “I can assure all our customers that there was no risk to them, and this was the only time that we have had this problem, which within 18 hours was corrected.”