The substance in Liqui Fruit 330ml red grape juice that was previously identified as “shards of glass” has just been identified as crystals of a naturally occurring substance in products of grapes called potassium bitartrate.

On Saturday 5 September, Pioneer Foods issued a national recall of a single batch of product, based on the likelihood that the substance found in the juice by three consumers were shards of glass.

“Following extensive elemental testing at separate specialist laboratories, we have since received confirmation that the glass-like crystals seen in the Liqui Fruit 330ml red grape juice is in fact the crystalline form of a substance that is commonly found in high concentrations in grapes and products of grapes,” Tertius Carstens, CEO of Pioneer Foods explained.

“The initial visual assessment by a laboratory of the sample as provided by a consumer indicated the matter to be glass. We opted to trigger the recall whilst we awaited the outcome of the technical analysis of the matter given the health and safety risk associated with the potential presence of glass in the product,” states Carstens.

Grapes naturally contain both tartaric acid and potassium. When these two elements bind together under chilly conditions, they form potassium bitartrate crystals that present as glass- like particles.  Potassium Bitartrate is a natural occurring material and non-toxic and commonly known as cream of tartar when used as a cooking aid.

Given the presence of the crystals the recall is continuing, and consumers are urged not to consume or dispose of the product but to return it for a full refund.