Kefir Grains

Water Kefir Grains are supposed to have originated in Mexico and are used to provide an alternative probiotic drink for people who cannot tolerate dairy.

The best explanation of Milk Kefir Grains I can find is shown below. If you want to learn more about the topic, as well as learn about Water Kefir Grains, visit the websites shown at the bottom of the page.

"[Milk] Kefir grains are a biological mass synthesized [created] by colonies of micro organisms living together [symbiotically] to form a polysaccharide mass, which form into lumps similar in appearance to cauliflower rosettes. Grain size varies from the size of wheat kernels to that of a golf ball or larger. Once placed in fresh milk, the grains [also referred to as a natural starter-culture or starter-culture], transform the milk into kefir within app. 24 hours. The same grains (or culture) are used for the next batch, to continue the ongoing process.

The grains originated in the Northern Caucasus Mountain region, where local people have been using the culture for centuries – perhaps for up to one and half to two thousand years. It is said that the people of this region were gifted kefir grains from Allah, or God. At the beginning of the 20th century, Russian nobel prize winner E. Mechnikov investigated the grain’s health promoting properties. This initially brought much interest in the product to the people of former USSR, which followed on to the the rest of the world."

Source:
http://www.gapsaustralia.com.au/kefir/
http://www.gapsaustralia.com.au/kefir-2/
[these two webpages are an excellent overview of kefir and it's importance for us humans]