These microorganisms are essential for the product to meet the international definition of kefir established by WHO and FAO.
Around 80% of the products labelled as “kefir” in Spain do not provide information about the presence of yeasts. These microorganisms are necessary for the product to meet the international definition of kefir set by the Codex Alimentarius, prepared jointly by the World Health Organization (WHO) and the Food and Agriculture Organization (FAO). This is the conclusion of a study led by a research team from the Department of Biochemistry and Biotechnology of the Universitat Rovira i Virgili and the Pere Virgili Health Research Institute (IISPV), presented at the latest congress of the Spanish Federation of Nutrition, Food and Dietetic Societies.
Kefir is a fermented dairy food that differs from other similar products, such as yogurt, because of its mixed fermentation, which is the result of the combined action of lactic acid bacteria, acetic acid bacteria and yeasts. In the study, carried out in the summer of 2025, products labelled as “kefir” were analysed in the main supermarkets of the country, selected according to the market share report of Kantar Worldpanel, which includes national and regional chains and covers more than 56.7% of the market. The labelling of 170 drinkable and spoonable kefirs was evaluated, paying special attention to the explicit declaration of yeasts.
The results showed a great variability in the information provided by manufacturers, which, according to the research team, may cause confusion among consumers and make it difficult to correctly identify the product according to international standards. “In many cases, the name ‘kefir’ is used as a commercial claim, even though the products do not meet the international definition, which requires the presence of yeasts,” explain Lucía Iglesias-Vázquez and Nadine Khoury, researchers of the study.
The authors warn that the current European regulation on food information does not require declaring the presence of microorganisms on food labels. Moreover, in some fermented dairy products it even allows the omission of the list of ingredients, which may reduce transparency and contribute to the trivialisation of a food like kefir, which offers many health benefits.
Faced with this situation, the research team suggests that the industry should adopt clearer and more consistent labelling practices, such as explicitly indicating the presence of bacteria and yeasts. “Moving towards a harmonised European regulation that sets minimum microbiological criteria would be essential to protect the authenticity of kefir and strengthen consumer confidence through a clear list of ingredients,” say Nancy Babio and Jordi Salas, professors and researchers from the Department of Biochemistry and Biotechnology of URV, IISPV and CIBEROBN.
Facebook 
Mail 
WhatsApp 