Malo sam kopala po internetu: nasi izvori kažu da se ispiraju, a strani da se ne ispiraju. Go figure!
Ovaj sajt mi deluje dobro potkovan istrazivanjima:
http://users.sa.chariot.net.au/~dna/kefir-faq.html#rinsing
Ukratko: ne treba ispirati jer se time remeti ritam mikroflore na povrsini gljivica.
DO I NEED TO RINSE KEFIR GRAINS OR FAST THEM IN WATER. WHAT'S BEST?
Under most circumstances kefir grains do not need to be rinsed with water [or fresh milk] between each milk change, or fasted in fresh cold water either. If you ever do rinse your grains with water, just be sure to use non chlorinated, sterile, COLD water [The water should first be boiled then cooled to room temperature]. Using fresh milk instead of water to rinse the grains should also be avoided, if the rinsing-milk is going to be discarded.
The rinsing of kefir grains has came about after the mother-culture was introduced to the western world, possibly in the belief that rinsing inhibits or removes weed microorganisms from the surface of the grains [this is modern-day microbe-phobia]. Rinsing the grains has been found to upset the rhythm of the microflora found on the surface of the grains. This is because of the fashion in which the organisms are arranged over the surface of the grain. With the use of clean, fresh milk to prepare kefir, there is very little risk in culturing weed microorganisms.
As far as I understand, where kefir originated, the people of Northern Caucasus did not rinse their kefir grains. These folks practiced the art of continuous fermentation. The kefir grains were constantly left in the same goatskin bag, and as portions of kefir was poured out from the bag daily, the bag was replenished with fresh milk. The milk they used came fresh from their milking animals, which went directly into preparing kefir [the milk was as fresh as you can get].
Any amount of curd which initially forms around each grain during the culture-cycle, forms a protective barrier around each grain. This may in fact help to inhibit weed microorganisms from propagating quite effectively than if rinsing the grains, which removes the protective acid-curd. When doing so the grains are exposed to the environment. The grains need a few hours to rebuild this curd, which once again will initially form around each grain. If one removes this curd on a daily basis through rinsing, then the chances of contamination becomes greater than if leaving an acid-curd protective-barrier around each grain at all times.
Rinsing kefir grains removes many important friendly microbes and yeasts from the surface of the grain, and possibly also removes certain protective compounds or mechanisms not yet discovered [or not well understood]. Such factors could be essential in maintaining a balance between the microflora and may inhibit weed organisms. Not to mention that removing friendly organisms from the surface of the grains reduces their counts, making conditions more favourable for weed organisms to thrive, due to less competition.
If you must rinse your grains due to habit, I suggest fasting your kefir grains by soaking the grains in pre-boiled, cold fresh water for 12 - 24 hours instead. This may be performed weekly, fortnightly or monthly instead or rinsing on a daily basis. Fasting kefir grains in water can be performed at room temperature or in the refrigerator. Although, this is not essential to perform either, but my own personal preferred method in an attempt to wean rinsing-addicts from rinsing their grains between each milk change. To perform the water-fast, use about 1 part grains to 3 parts water by volume [use pre-boiled then cooled good quality water, boiled without a lid on the pot to evaporate any chlorine found in tap water]. After a 12 - 24 hour water-fast, strain the grains and then use them for preparing kefir per usual. The strained-water is quite slippery, due to the soluble polysaccharide, kefiran. I've named this compound solution, Kefiraride. [Please see next FAQ for tips and recipes for using kefiraride as a natural healing-promoting agent, and more].
The Exception to the No-Rinsing Rule
Viili Cross-contamination. Milk kefir-grains easily become cross-contaminated if the grains come in contact with Viili [Piima]; a Nordic or Scandinavian ropy culture milk-product. If culturing Viili in close proximity to kefir, kefir grains may begin producing a kefir with a ropy consistency, making it next to impossible to strain the culture-milk through a sieve. Kefir grains readily adopt the Lactococcus lactis subsp. cremoris SBT 1275 organism, a specific type-strain responsible for the blob-like or ropy consistency of Viili. One only needs to use the same spoon to stir or scoop Viili, which later comes in contact with kefir grains, for cross-contamination of kefir grains. Even if days later the same spoon comes in contact with kefir grains, the grains will end up producing a cross between kefir and Viili [Kefiili] within a short period. To remedy this problem, water-fast pre-rinsed kefir grains in fresh, clean water for 24 to 48 hours, resting the grains in the refrigerator during the water fast. Strain the grains through a sterile sieve, rinse the grains with cold sterile water and then culture in fresh milk per usual [making certain to sterilise the jar and lid first]. The rinsing and fasting of Viili cross-contaminated kefir grains may need to be performed more than once, and possibly up to 3 times.
Non homogenized, but pasteurised full cream cow's milk may cause problems to kefir grains, after time. This is due to the denaturing of milk-fat through the pasteurisation of non homogenized whole cow's milk. In this case, the milk-fat becomes similar to butterfat, which could readily adhere to the surface of kefir grains that come in contact with the milk-fat during fermentation, especially during warmer conditions where the milk fat is an oily state. Such grains will end up with fat deposits [yellow milk-fat], partially covering the surface of any effected grain. Such grains will have mottled or patches of yellow milk fat. This milk-fat may suffocate the grains in this case, if the fat is left adhered to any grain over a length of time. To remedy this problem, place the grains in a bowl filled with luke warm water, no hotter than body temperature, and remove any adhered yellow milk-fat from the surface of kefir grains, with a gentle rubbing action between two clean fingers.
When dehydrating kefir grains, it is recommended to first rinse the grains with fresh, clean cold water to remove proteins [kefir] adhered to the surface of the grains before drying.
