Which? names Tesco kefir top in blind supermarket taste test; M&S product ranks lowest

Consumer watchdog Which? has crowned Tesco Gut Sense Plain Kefir the best supermarket kefir in a blind taste test of seven store-brand and branded products, while M&S’s Good Gut Organic Natural Kefir placed last.

Testers assessed each kefir on cost, texture and tanginess, with the Tesco product praised for its tangy flavour and creamy mouthfeel. The M&S drink was rated the weakest by tasters, who described it as too runny and lacking in both sweetness and creaminess.

Kefir is a fermented milk beverage similar to a thin yoghurt that has been gaining shelf space and consumer attention for its potential gut-health benefits. Which? noted that a 250ml serving typically provides roughly 40% of daily calcium needs, making the drink a source of dietary calcium as well as live cultures.

Which? nutritionist Shefalee Loth cautioned that consumers should remain mindful of total sugar intake but said the sugar present in kefir is predominantly lactose from milk. "While we should all keep an eye on sugar intake, the sugar in kefir is in the form of lactose, so it doesn't have the same negative impact as added sugars and isn't damaging to teeth," she said in comments published alongside the tasting.

The blind taste test aimed to combine sensory evaluation with value for money. Testers assigned scores for texture and tanginess and factored in price to arrive at overall rankings. Tesco’s Gut Sense Plain Kefir scored highly for a balance of tangy flavour and creamy texture, traits often cited by consumers who prefer drinking kefir as an alternative to spoonable yoghurts. The M&S Good Gut Organic Natural Kefir, by contrast, scored lowest because panel members found it too watery and insufficiently rounded in taste.

Kefir's rising popularity has led supermarkets to expand ranges that include plain, flavoured and organic options, as well as products marketed specifically for gut health. Nutritional profiles vary between brands and styles; some flavoured or sweetened kefirs can contain added sugars that change calorie and sugar content compared with plain varieties.

Which? did not recommend a single product over broader dietary guidance, but the test underscores differences in texture, flavour and cost among readily available kefir options. Consumers seeking higher calcium and probiotic content are advised to check labels for sugar, live culture claims and portion sizes when choosing between brands.

Retailers and manufacturers have increased kefir presence on shelves to meet consumer interest in fermented foods, and the Which? tasting provides a comparative snapshot of how mainstream supermarket offerings currently measure up on taste and value.