An Irish cheese manufacturer that supplies Tesco and Asda among others, has claimed it is facing losses of more than €10m because of an allegedly defective ingredient that gave its product "a soapy aftertaste and an off-flavour".

Carbery, of County Cork, is suing food ingredients suppliers Carbon Chemicals Group and Netherlands-based DSM Food Specialities in a case due to be heard in the Irish Commercial Court.

In its claim, Carbery said it had reached agreement with Carbon Chemicals in March last year to purchase rennet manufactured by DSM under the brand name Fromase 220XL.

It alleged certain batches of the ingredient subsequently supplied were defective, having been contaminated with an excessive level of the enzyme lipase. Cheese made using contaminated batches had an "off-flavour and a soapy aftertaste" and was unfit to be supplied, according to Carbery, which claimed a "very significant" quantity of the product had been affected. In September last year it was notified by Carbon Chemicals of "a possible issue" with certain batches of Fromase 220XL.

Carbery said it feared that because of the contamination, the Irish Dairy Board, which purchases its cheese, would not pay for product already supplied.

It claimed it had been the exclusive supplier of low-fat cheese to the Dairy Board and that as a result of the contamination this arrangement had been lost.

The company also expressed concern that cheese sold under the Tesco Carbery sub-brand would lose market share. A sub-brand just launched with Asda would also suffer, it claimed.

In an initial ruling, Mr Justice Peter Kelly agreed the action should be heard in the Commercial Court. The issue, he said, was whether rennet supplied to Carbery was defective.

Carbery, formerly known as Carbery Milk Products, produces a range of cheeses, food ingredients, flavours and alcohol. It supplies food manufacturers and foodservice as well as retail outlets.