25 November 2010 § 4 Comments
I got my milk kefir grains on 4 Nov 2010 from one source and on 11 Nov 2010 from another source. They came from sources in Belgium, Australia and Spain, but have been cultured in Belgium for a while. My milk kefir grains are growing relatively fast. I already gave half of them away to a colleague. If I find a way to send them I’ll send some to friends.
At the moment I make 500 ml each day, but if they keep growing I need more than ½ litre or have shorter milk changes. At the moment I am trying to have a rotation of 2 kefir containers going: I take half of the kefir out of each and refill with fresh milk every other day on alternate days, so far I have been using organic cow’s milk, either raw or pasteurised and either full or half fat, depending on what kind of milk I find. My method of making kefir still has to be improved, though.
At the moment I am experimenting with hermetically closing my container, last week I left it open, and it seems that it does not make a huge difference. If I want to stick to my half litre measure, I will have to give away or eat half of my grains every week, so that I have a nice not too fermented kefir after 24 hours.
Filtering the kefir grains is not easy because of the curd substance adhering to the grains, so if a strainer is used it has to be shaken quite vigourously, or a wooden spoon or your hand has to be used to stir the grains in the strainer. Shaking the container with the kefir before straining helps, too. There are lots of videos on youtube explaining this.
UPDATE spring 2012
Of course this first batch died in the summer 2011 because of my carelessness, but meanwhile, over Christmas 2011, I got new grains from Canada, that were bought in Germany and I improved my kefir making method: Now I am making a small amount of kefir (100 to 200 ml) for 24 hours outside the fridge with the kefir grains and 24 hours inside the fridge without the grains. I have the kefir jars always closed, never open. I never shake the glass jars. This gives a well tasting kefir. I don’t strain the kefir anymore, I stir and then I just take out the largest kefir grain and re-use it. The smaller pieces that stay I drink with the liquid. At one point I only had 12 very small pieces. Then I used a colander with 4 mm sized holes to strain the kefir.
24 November 2010 § 1 Comment
The origin of milk kefir is described in the paper by M. Motaghi, M. Mazaheri, N. Moazami, A. Farkhondeh, M.H. Fooladi and E.M. Goltapeh, Short Communication: Kefir production in Iran (World Journal of Microbiology & Biotechnology vol. 13 pp. 579-581, 1997):
“A goat-hide bag (4-l capacity) obtained from Pariz and Babak villages in Kerman (Southwest Iran) was washed several times with sterile water, filled with pasteurized milk and intestinal flora from sheep. It was kept at 24 to 26°C for 48 h and shaken hourly. When the milk was coagulated, 75% was replaced with fresh milk. This procedure was repeated for 12 weeks. Gradually a polysaccharide layer (spongy form) appeared on the surface ofthe hide. The layer was removed aseptically from the hides and propagated in pasteurized cow’s milk. Kefir grains of variable size (0.5±3.2 cm in diameter) were added several times to the fresh cow’s milk.”
and also by Semih Otles and Ozlem Cagindi in the paper “Kefir: A Probiotic Dairy-Composition, Nutritional and Therapeutic Aspects” (Pakistan Journal of Nutrition 2 (2): 54-59, 2003):
“Kefir grains are prepared in a goat-hide bag fill[ed](ing) with pasteurized milk inoculated with sheep intestinal flora, followed by culture of the surface layer in milk. Gradually a polysaccharide layer appears on the surface of the hide. The layer is removed from the hides and propagated in pasteurized milk. Kefir grains appear [as] pieces of coral or small clumps of cauliflower florets or pop corn and range from 3 to 20 mm in diameter…”
This kefir has to be distinguished from the sugar water kefir (tibi).
The matrix in which the symbiosis of fungi and bacteria grow has been identified as being dextran for the sugar water kefir, whereas for the milk kefir it is kefiran which is made by different kinds of bacteria than those present in the sugar water kefir.
The following summary is from the sugar water kefir page where links to the references are present:
Sugar-water kefir (tibi) forms on the leaves of the Opuntia cactus (orig. Mexico) as hard granules (Lutz, L.: Recherches biologiques sur la constitution du Tibi. Bull. Soc. Mycol. France 15, 68-72 (1899), and Stacey M. and Youd, F.R.: A note on the dextran produced from sucrose by Betacoccus arabinosaceous haemolyticus Biochem J. 1938 November; 32(11): 1943–1945.
These two references seem to be the only ones referring to the origin of the sugar water kefir (tibi) grains which seems a bit strange given the age of the publications. I cannot recall seeing tibi on my grandmother’s Opuntia when it was still living (1990s), but I did not really look for them either.
These sugar water grains have also been identified with the ginger beer plant in other scientific articles (M. Pidoux
(The microbial flora of sugary kefir grain (the gingerbeer plant): biosynthesis of the grain from Lactobacillus hilgardii producing a polysaccharide gel, World Journal of Microbiology and Biotechnology, Springer Netherlands, pp. 223-238, vol 5(2), http://dx.doi.org/10.1007/BF01741847, 1989).)
There has certainly occurred cross-contamination of the two so that even in scientific studies the naming/distinction of the two can differ. I also wonder if different ingredients can change the fungal and bacteriological composition leading to the different names of the sugar water kefir that is tibi, tibicos, water kefir grains, sugar kefir grains, Japanese water crystals, California Bee (from wikipedia) and in older literature also known as Bébées, African bees, Ale nuts, Australian bees, Balm of Gilead, Beer seeds, Beer plant, Bees, Ginger Beer plant, Ginger bees, Japanese Beer seeds and Vinegar bees from Kebler (1921)).
[Kebler, Lyman F. (1921) “California bees.”, J. Pharm. Sci., vol. 10(12), pp. 939-943, http://dx.doi.org/10.1002/jps.3080101206