The company, which is also the maker of Irn-Bru, is recalling four batches of Rubicon Sparkling Mango two litre soft drink because yeast fermentation has resulted in the products becoming unfit for human consumption and liable to potentially explode. Fermentation is a metabolic process that converts sugar to acids, gases, or alcohol. The company was unable to confirm reports that some of the product had already turned to alcohol. A G Barr released a safety notice saying: "As a precautionary measure A.G. Barr is withdrawing four batches of its Rubicon Sparkling Mango two litre soft drink from the market because of signs of fermentation and the possibility that increased pressure caused by this fermentation may cause the bottle to burst. "If drunk, whilst the liquid may be unpleasant in taste or odour, it is not harmful to health. "No other batches of Rubicon Mango, or any other flavours, are known to be affected."