Water Kefir Grains: What Are They Made of?

If you are reading this post right now, you probably know what kefir is and that we use “grains” to make it. But, like me, you want to know more. What are those kefir grains made of? Are they really grains? Don’t worry, I did the research and I will give you the answer in plain English.

So, what are water kefir grains made of? They are made of beneficial bacteria, yeast, and polysaccharide (sugar). They are called grains because of their appearance in clusters that look like grains or crystals but have a gelatinous texture.

Those small and a bit weird-looking “grains” have a great variety of strains of beneficial bacteria and yeast and are capable of fermenting water and turning it into a delicious drink.

Which beneficial bacteria are in the water kefir grains?

If you are looking for the bacteria’s names, below is a quote that lists the main strains of bacteria and yeast found in water kefir grains.

The microflora of sugary kefir grains was principally mesophilic and consisted chiefly of lactic acid bacteria [Lactobacillus casei, Lactobacillus hilgardii (=brevis), Leuconostoc mesenteroides ssp. dextranicum, Streptococcus lactis] and a small proportion of yeasts (Zygosaccharomyces florentinus, Torulospora pretoriensis, Kloeckera apiculata, Candida lambica and C. valida).

Pidoux, M. (1989). The microbial flora of sugary kefir grain 

It is worth reiterating that there are many other strains of lactic acid bacteria in water kefir than mentioned above. The variety is enormous, and every colony has its diversity of bacteria and yeast living in a symbiotic relationship. The ones cited are the most present and represent a higher percentage of the bacteria found in the grains analyzed by Pidoux. If you want to read the study in detail, the link is at the bottom of the quote.

Lactobacillus caseiZygosaccharomyces florentinus
Lactobacillus hilgardiiTorulospora pretoriensis
Leuconostoc mesenteroidesKloeckera apiculata
Streptococcus lactisCandida lambica 
Main bacteria and yeast in Water Kefir Grains (PIDOUX)

You probably noticed that most of the bacteria present in water kefir grains are lactic acid bacteria. Although there is the word lactic in the name, these bacteria are not related to milk.

Lactic Acid Bacteria only have this name because the first one of these bacteria to be identified was found in dairy products. However, they can be seen in different environments, mostly in the ones rich in carbohydrates, like fermented vegetables, plants, humans, animals, kombucha, and kefir.

In addition, these bacteria are essential for the healthy functioning of the gut, being present in the human microbiota. Yes, when you eat yogurt or probiotics, more often than not, you are eating lactobacillus (aka lactic acid bacterias).

In the human and animal bodies, LAB [lactic acid bacteria] are part of the normal microbiota or microflora, the ecosystem that naturally inhabits the gastrointestinal and genitourinary tracts, which is comprised by a large number of different bacterial species with a diverse amount of strains.

Lactic Acid Bacteria as Source of Functional Ingredients
By Panagiota Florou-Paneri, Efterpi Christaki and Eleftherios Bonos

Those lactic acid bacteria are fascinating, and although there is still much to be discovered about them, one thing is certain: they are essential for gut health and should be consumed often.

So, when the “grains” are immersed in sugar and water, the bacteria ferment the sugar, creating lactic acid, ethanol (but just a bit), and carbon dioxide. It is the same process as the one present in vegetable fermentation or kombucha.

From the strains found in water kefir grains listed above, one is quite intriguing. Lactobacillus hilgardii. This strain is the one that produces the substance that makes most of the appearance of the “grains” and pulls everything together.

The gelatinous part of the “grains” are made of polysaccharides produced by one particular strain of bacteria, the Lactobacillus Hilgardii. In other words, this bacteria produces a jelly kind of sugar that attaches the yeast to the bacteria. It is also the polysaccharides that give the format and looks of the grains.

The study quoted before was able to separate the Lactobacillus Hilgardii strain and produce more of this substance that “glues” all the bacteria and yeast.

Observation by scanning electron microscopy revealed that the filamentous yeasts adhered to the bacteria on the periphery of the grain. Lactobacillus hilgardii, the single microorganism isolated which was able to produce a gelling polysaccharide, was important in the biosynthesis of the grain. Pieces of gel produced by this strain, and transferred in a yeast extract-sucrose solution, grew and resembled the household kefir grains.

Pidoux, M. (1989). The microbial flora of sugary kefir grain 

As the lactic acid bacteria ferment the sugary water, the bacteria, and yeast multiply. They then become “glued” together, growing new clusters of bacteria, yeast, and polysaccharides. That is how the “grains” are able to multiply pretty fast, leaving us, kefir enthusiast, with a substantial amount of grains.

Water kefir is both vegan and gluten-free since the grains are made from bacteria, yeast, and polysaccharides. To make the beverage you only need water and sugar to ferment it. Optionally, you can add a few fruits if you want to flavor it.

Where do the grains come from?

The exact history of the grains and where they come from is a bit obscure. But the main version says that they originated in Mexico with the name of tibicos, as some “grains” on the leaf of a cactus called Opuntia. The first documented use of Tibiscos is around 1850, in Mexico.

The Tibis grains are known to originate from a Mexican cactus (Opuntia) where they were taken off the leaves. However, uncertainty remains about the origin of the other grains. Beijerinck (1889) linked the ‘kefir grains’ to the gingerbeer plants that English soldiers brought back from the Crimean war in 1855.

Pidoux, M. (1989). The microbial flora of sugary kefir grain 

Other stories describe the use of grains similar to water kefir grains in Tibet and Ukraine, around the same period. Since each colony of grains has an own variety of bacteria strains and a unique ratio of them, it is not possible to trace it back to its exact origin.

Other Names for Water Kefir Grains

Since its origin is not clear and water kefir grains can be found all over the world, there is a good variety of names from different cultures.

Some of water kefir grains names are:

  • Tibicos
  • California Bees
  • Gingerbeer plant
  • Japanese water crystals
  • Sugar Kefir Grains
  • Australian bees
  • Piltz, in Germany
  • Graines Vivantes, in France
  • Kefir di Frutta, in Italy

Michel Pidoux dedicated part of his scientific career to the study of Kefir grains. Below is a quote from one of his studies where he lists the most referenced names. It is interesting to see that some of his references are from the late 1800s, meaning that scientists from that period were already interested in investigating this marvelous drink.

These grains have been given various names such as Gingerbeer plants (Ward 1892; Hesseltine 1965), California bees (Kleber 1921), Tibis grains or Tibi-complex (Lutz 1899; Horisberger 1969; Moinas et al. 1980).

Pidoux, M. (1989). The microbial flora of sugary kefir grain 

Can you eat the grains?

So, now you know what they are made of, you know how they multiply, and you are probably wondering. If they are made of the same substance present in the drink plus sugar, that means I can eat it, right?

So, the short answer is, you can eat water kefir grains. The logic above is correct, and it is just beneficial bacteria, yeast, and polysaccharides.

You can even find some recipes online. I haven’t eaten them yet, but if I do, I will update it here. My dad loves them sautéed with onions. But, as always, you should listen to your body and your doctor and ease yourself into it.

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