Spain’s kefir boom exposes regulatory gap over yeast-free products
Kefir consumption in Spain has grown 324% since 2020, with sales reaching €128 million in 2024. The absence of a specific national definition allows products made without yeast to use the same name as traditionally fermented kefir.
Sales rise as kefir enters the mainstream
Spain’s kefir market is expanding rapidly, but regulation has not kept pace with the category’s growth. According to market-research company IRI data cited by AENOR, consumption increased by 324% from 2020, while sales reached €128 million and the product attracted more than 11.9 million consumers in Spain in 2024.
The expansion has moved kefir from a specialist fermented food into a mainstream supermarket category. Producers ranging from large dairy groups to organic and artisanal operators now compete for buyers interested in fermented foods. Yet products sold under the same name can be made using materially different cultures and processes, complicating comparisons for consumers and competition among manufacturers.
One name covers two different products
The central issue is yeast. Traditional kefir is produced by fermenting milk with a community of lactic-acid bacteria and yeasts found in kefir grains. The Codex Alimentarius standard CXS 243-2003, developed through the FAO and WHO, defines kefir by this combination. Yeast activity also contributes to its characteristic acidity and slight effervescence.
Spanish food rules mention kefir as fermented milk but do not provide a specific, harmonised definition or dedicated quality parameters. The Madrid regional government says the market consequently includes both traditional kefir made with bacteria and yeast and products fermented only with lactic cultures. The second group may have a similar flavour and texture, but it does not correspond to the traditional form described by the Codex standard.
Labels do not always resolve the difference
European Union food-information rules do not generally require manufacturers to identify every microbial species used in fermented milk. In some cases, fermented dairy products also need no ingredients list when nothing beyond dairy ingredients, enzymes and essential microbial cultures has been added. The absence of yeast from a label therefore does not necessarily prove that the product contains none, but it makes verification difficult for buyers.
A 2025 study by researchers from Universitat Rovira i Virgili and the Pere Virgili Health Research Institute examined 170 products from 46 brands sold as kefir. The sample covered supermarkets representing about 60% of the market, and around 80% of the products did not state whether yeast was present. Separately, Servimedia reported that a 40dB study found seven in ten consumers were buying products regarded as not authentic kefir, while nine in ten wanted clearer regulation.
Definition could reshape competition
The regulatory question affects product development, labelling and production costs. A rule reserving the word kefir for fermentation involving both bacteria and yeast would give traditional producers a clearer point of differentiation. Manufacturers using only lactic cultures could need a different product name or an explicit qualifier, as occurs in markets that distinguish traditional kefir from milder versions.
There has already been movement on advertising claims. AENOR reported that Spain’s advertising self-regulatory body AUTOCONTROL ruled in July 2025 that describing yeast-free products as kefir could mislead consumers and breach advertising-truthfulness requirements. That decision does not itself create a national food standard, leaving producers, retailers and regulators with a fast-growing category whose commercial name remains more precise internationally than it is under Spanish rules.
