Updated: Mar 6
What is Kefir? I’m hoping that you’ve heard of kefir and some of you may even have tried the Nettlebed Creamery kefir. Kefir is fermented milk; fermentation is basically the conversion of sugars into something else by the action of microorganisms. This can be alcoholic fermentation, where glucose is fermented by yeasts to make alcohol, or it can be lactic acid fermentation where lactose is fermented by bacteria to make lactic acid. Both of these types of fermentation form a method of food preservation, as the presence of alcohol or the lower pH generated by the production of lactic acid, as well as competition for nutrients, makes it harder for disease-causing microorganisms to grow.
Milk can be fermented in slightly different ways to produce very different results; cheese is a form of fermented milk, as is yogurt, and of course kefir. Kefir tends to contain a much wider array of microorganisms than either cheese or yogurt due to the starter cultures that make it, and it is this collection of microorganisms that not only create lactic acid but produce various enzymes, vitamins, and flavour compounds that give kefir its unique taste and texture. If you haven’t tried kefir before, it is halfway between the consistency of milk and yogurt, it can have a slight fizziness, a sharpness that you do not get in yogurt, and some of the fresh sourness that you do get in yogurt.
Where did Kefir come from?
Photo Credit: Cultured Food Life!
Kefir is thought to originate from the Caucasus mountains and was made by the nomadic mountain people who lived there as a way of preserving milk. It is made by incubating milk with kefir grains; these grains look nothing like the wheat or barley that might come to mind, but instead more closely resemble pieces of cauliflower. These grains are composed of a complex network of different species of bacteria and yeasts all trapped in a matrix of protein and sugars called kefiran which ferment the milk, as can be seen in figure 1 (1).
These grains formed naturally, and whilst many have tried, no one has managed to create a successful artificial replica (although you can buy a powdered collection of many of the bacteria and yeasts in the grains made in a lab); their creation occurred so spontaneously and apparently miraculously that many believed they were a gift from the prophet Mohammed. Another belief was that kefir grains are in fact the manna that God gave to feed the Israelites whilst they wandered the desert for 40 years. These days the leading theory is that the grains came about by fermenting milk in sheep and goat skin bags which provided the right environment for the bacteria and yeasts we see in kefir to team together and produce enough kefiran (this is produced by one species of Lactobacillus, but its formation is egged on by another yeast) to stick them all together (1). Photo credit: Revolutionfermentation.com (Nomadic women pouring milk in a goat skin)
The grains became a highly guarded secret in the communities that used them; whilst visitors were permitted to drink kefir, none could know the method of making kefir nor given the grains. This secret became highly coveted by members of the Russian medical community when it came to light that kefir drinkers in the Caucasus region had (and still have) very long lifespans, often living well into their hundreds, which even then was attributed to improved digestion (2) (perhaps the gut microbiome isn’t such a hot new idea!). Many people offered large amounts of money to buy kefir grains off the people of the Caucasus Mountains, but they would not give in.
Eventually, the Blandov brothers, who owned a cheese-making factory in Russia came up with a plan. They sent Irina Sakharov, one of their employees, to Bek-Mirza Barchorov, a prince of one of the Caucasus Mountains tribes, with the aim to court him and convince him to give up some grains. While the prince was very taken with Irina, he would not give up the grains, and so Irina left to return home. On her way back however, she was kidnapped by the prince who wanted to force her into marriage. The Blandov brothers rescued her and took her to the Russian court of Czar Nicholas II so that she could raise a complaint against the prince. The Czar ordered the prince to make reparations to Irina for her mistreatment, and no matter what riches he offered her, Irina refused anything but the kefir grains until he had no choice but to give them up (3). The Blandovs began making and selling kefir in Russia in 1908, and it quickly spread across Russia and is still very popular there today. In 1973 the Russian government sent a letter to Irina to thank her for her “heroic” efforts in obtaining this most precious thing.
Why should I drink Kefir?
Apart from the enjoyable taste of kefir, part of the reason it is so popular is its health benefits.
Due to the diversity of the microorganisms in the grains, kefir contains a wide range of microbes many of which have probiotic properties. Research has found that consumption of kefir can change the gut microbiome and preliminary results suggest that it can improve bowel symptoms of patients with functional constipation and it is effective at eradicating the bacterium associated with stomach ulcers, however further research into how kefir can help with different gut disorders will further elucidate what this drink can do (4–6). Further to the direct effect on gut health, kefir also has evidence showing it can modulate the immune system, metabolise cholesterol, help with wound healing, and it has anti-carcinogenic, anti-allergenic, and antimicrobial properties, all of which I will delve further into in a future article (7).
Until then, if you’d like to see what all the fuss is about pop by the Cheese Shed and either pick up a bottle of kefir to drink on its own or pour over fruit or cereal, or try one of our kefir smoothies.
Figure 1 – Scanning electron microscopy images of a kefir grain and all the microbes present. A, C, and E show the outer part of the grain, and B, D, and F show the inner portion. In A, the arrow indicates a cocci cell, which is a bacterium that is round in shape. In D, the arrow indicates fibrous material, this is the kefiran. In E, the arrows indicate 1: coagulated protein, 2: different species of yeast. (8)
1. Prado MR, Blandón LM, Vandenberghe LPS, Rodrigues C, Castro GR, Thomaz-Soccol V, et al. Milk kefir: composition, microbial cultures, biological activities, and related products. Front Microbiol [Internet]. 2015 [cited 2023 Jan 27];6(OCT). Available from: /pmc/articles/PMC4626640/
2. Kefir: A Wonder Beverage from the Ancient World [Internet]. [cited 2023 Jan 27]. Available from: https://www.healthygutbugs.com/kefir-wonder-beverage-ancient-world/
3. Shavit E. Renewed Interest in Kefir, the Ancient Elixir of Longevity. 2008;
4. Kim DH, Jeong D, Kim H, Seo KH. Modern perspectives on the health benefits of kefir in next generation sequencing era: Improvement of the host gut microbiota. https://doi.org/101080/1040839820181428168 [Internet]. 2018 Jun 17 [cited 2023 Jan 27];59(11):1782–93. Available from: https://www.tandfonline.com/doi/abs/10.1080/10408398.2018.1428168
5. Bekar O, Yilmaz Y, Gulten M. Kefir improves the efficacy and tolerability of triple therapy in eradicating Helicobacter pylori. J Med Food. 2011 Apr 1;14(4):344–7.
6. Turan İ, Dedeli O, Bor S, Gastroenterol Tİ-TJ, 2014 undefined. Effects of a kefir supplement on symptoms, colonic transit, and bowel satisfaction score in patients with chronic constipation: a pilot study. Citeseer [Internet]. 2014 [cited 2023 Jan 27];25(6):650–6. Available from: https://citeseerx.ist.psu.edu/document?repid=rep1&type=pdf&doi=80916df706e984efe10ae452e6d31342c1e3af70
7. Bourrie BCT, Willing BP, Cotter PD. The Microbiota and Health Promoting Characteristics of the Fermented Beverage Kefir. Front Microbiol [Internet]. 2016 [cited 2023 Jan 27];7(MAY). Available from: /pmc/articles/PMC4854945/
8. Leite AM de O, Miguel MAL, Peixoto RS, Rosado AS, Silva JT, Paschoalin VMF. Microbiological, technological and therapeutic properties of kefir: a natural probiotic beverage. Brazilian J Microbiol [Internet]. 2013 Jan 1 [cited 2023 Jan 27];44(2):341–9. Available from: http://www.scielo.br/j/bjm/a/j7s8Vnc9qz6FkQKCjrNDGPb/abstract/?lang=en