Kefir is a traditional
fermented dairy product of the northern Caucasus. It is produced by fermenting
milk with kefir grains, which are a mixture of yeasts and lactic acid bacteria.
As a result, ethanol, lactic acid and carbon dioxide are also components of the
final kefir product. In its traditional state, it is a highly viscous beverage.
In this study, we were successful in our goal of producing a smoother,
easier-drinking kefir by reducing viscosity. Three methods were useful in this
pursuit: enzymolysis, the addition of whey before
fermentation, and, most effective of the three, fermentation combined with a
mixing action. In the last of these methods, milk was fermented using kefir
grains (10% of the milk by volume) for a period of 5 hours. During that time,
the fermenting mixture was maintained at a constant 20'C and agitated by
revolving it at 120 rpm. After that, the kefir grains were sieved out. The
remaining milk was allowed to ferment at 15'C for a further 18 hours in a
static state. The result was a new, low-viscosity kefir product of about 60cP.
Although smoother and readily drinkable, this new product did not suffer any
loss of kefir flavor. As an additional benefit, the filtered kefir grains were
reusable and remained effective in fermenting additional milk even after 10
uses.