Shares in Dairy Crest fell 24 pence, around three per cent, throughout Tuesday after the group confirmed it was recalling all sizes of Clover with a best before date of 10 August. The recall is expected to cost the firm £1m after insurance, and the incident serves as a reminder to food firms of how faults in the production line can quickly escalate. Dairy Crest, which has stopped Clover production at its Shropshire plant, said Tuesday the source of the contamination was still not clear. It said in a statement that affected products may "develop an unpleasant taste before the end of [their] shelf life due to the development of a mould most commonly found in blue cheeses". As well as the added costs, Dairy Crest may wince at the bad timing of the Clover recall, after recently announcing its intention to launch a 'lighter' version of the spread brand later this year. But the group has moved quickly to tackle consumer concerns, apologising to customers on its website and offering refunds for suspect products. 'Sorry' is the crucial word for firms attempting to retain consumer trust, according to a recent survey by the British Standards Institute. More than a third of consumers asked said they would not have defected to a rival brand or service if they had received "a simple apology". Openness and swift action are key to handling a recall, according to Jeremy Moore, a leading risk assessment specialist working for risk consulting practice, Marsh.