milk kefir: what it is & how to brew it

Milk kefir is, to put it lightly, an acquired taste.   Sour and pungent, milk kefir is a cultured dairy food originally from the Caucuses – the region where Europe meets Asia.   There it has been traditionally heralded as an elixer of long life and health.   It seems that there’s wisdom in this tradition: milk kefir is rich in beneficial bacteria, phosphorus, vitamin K, biotin and folic acid – nutrients that are essential to health and well-being.   A single component of milk kefir – kefiran – may prove particularly beneficial as it successfully protects beneficial bacteria from damage in the hostile environment of the digestive tract¹.

Milk kefir is strongly anti-inflammatory² and may prove helpful in combating   gastro-intestinal distress caused by infections from bacillus cereus³, salmonella, e coli and helictobacter pylori⁴.   Milk kefir is also particularly important in recovering from clostridium difficile infection and associated gastrointestinal discomfort and diarrhea which often accompanies use of antibiotics⁵.   Despite the fact that milk kefir is, itself, a symbiotic colony of bacteria and yeasts (or SCOBY), milk kefir also acts as a powerful antimicrobial food – helping to limit the growth of pathogens while encouraging the proliferation of beneficial bacteria in the intestinal tract.

Milk kefir, like other cultured dairy foods,   may also play a role in the prevention of cancer as it exhibits antitumoural effects⁶.   Cultured dairy foods, including milk kefir, have been found to play a role in the prevention and treatment of bladder cancer⁷, breast cancer⁸ and colon cancer⁹.   Indeed, some researchers have concluded that milk kefir may be one of the most promising foods when it comes to cancer prevention¹⁰.

Milk kefir is cultured from a symbiotic colony of bacteria and yeasts (SCOBY) that is coloquially referred to as kefir grains.   The appearance of these small colonies of bacteria and yeast vaguely resembles that of cottage cheese or even cauliflower.   Milk kefir grains are white, lumpy and gelatinous and are comprised primarily of lactic acid producing bacteria including lactobacillus brevis, streptococcus thermophillus, lactobacillus casei, lactobacillus helveticus, lactobacillus delbrueckii as well as yeasts that include candida maris, candida inconspicua and saccharomyces cerevisiae¹¹.   Though, of course, strains of bacteria present may differ from one culture of grains to another.

Obscure and exotic as it may seem, milk kefir is neither difficult to acquire nor difficult to prepare.   As with many traditional foods, its beauty lies in its simplicity.   It’s easy to begin preparing kefir and incorporating it into your family’s dietary rotation.   Once you’ve acquired a kefir grains, simply mix them in with milk – preferably   raw – and allow it to culture at room   temperature for 24 – 48 hours.   As it cultures at room temperature, the beneficial strains of bacteria and benign natural yeasts will proliferate, metabolize the milk’s lactose and create a sour, thick beverage replete with vitamins, probiotics, kefiran and other nourishing components.   The longer milk kefir cultures the more sour and folate-rich it becomes, but take care not to culture it too long lest it become unpalatable.

prepare milk kefir at home

Preparing milk kefir at home is remarkably easy and quite affordable.   It takes considerably less effort than homemade yogurt and homemade yogurt requires very little effort, indeed.

milk kefir: ingredients

• 1 tablespoon milk kefir (see sources)
• 1 quart fresh raw milk (see sources)

milk kefir: equipment needed

• 2 1-quart Sized Mason Jars with lid and band
• Small, nonmetal sieve or tea strainer
• Wooden Chop Stick or Small Wooden Whisk

milk kefir: instructions

1. Place milk kefir grains in the bottom of a clean mason jar. Cover with 1 quart fresh milk.
2. Very loosely, place the lid and band on the mason jar.   You do not want to tighten it because, as with all fermentation, carbon dioxide is created and needs to escape.  Culture for 24 – 48   hours at room temperature.   For a for a thin, mild kefir you can culture for 12 hours.
3. Once culturing is complete, strain milk kefir into a new mason jar, cap and refrigerate.  Begin reculturing a new batch of kefir, if desired or allow your kefir grains to rest in water in the refrigerator for a few days until you’re ready to make kefir again.

Sources

1. Zhou et al. Assessment of the sequential simulated gastrointestinal tolerance of lactic acid bacteria from kefir grains by response methodology. Journal of Food Science. 2009. August.

2. Rodrigues et al. Anti-inflammatory properties of kefir and its polysaccharide extract. Inflammopharmacology. 2005.

3. Medrano et al. Kefiran protects Caco-2 cells from cytopathic effects induced by Bacillus cereus infection. Antonie von Leeuwenhoek. 2009.

4. Thirabunyanon et al. Probiotic potential of lactic acid bacteria isolated from fermented dairy milks on antiproliferation of colon cancer cells. Biotechnology Letters. 2009. April.

5. Bakken. Resolution of recurrent Clostridium difficile-associated diarrhea using staggered antibiotic-withdrawal and kefir. Minnesota Medicine. 2009. July.

6. Urbanska et al. Estimation of the potential antitumor activity of microencapsulated Lactobacillus acidophilus yogurt formulation in the attenuation of tumorigenesis in Apc(Min/+) mice. 2009. February.

7. Larsson et al. Cultured milk, yogurt and dairy intake in relation to bladder cancer risk in a prospective study of Swedish men and women. American Journal of Clinical Nutrition. 2008. October.

8. Chen et al. Kefir extracts suppress in vitro proliferation of estrogen-dependent human breast cancer cells but not normal mammary epithelial cells. Journal of Medicinal Food. 2007. September.

9. Saikali et al. Fermented milks, probiotic cultures, and colon cancer. Nutrition and Cancer. 2004.

10. Liu et al. Antitumour activity of milk kefir and soy kefir in tumour-bearing mice. Nutrition and Cancer. 2002.

11. Simova et al. Lactic acid bacteria and yeasts in kefir grains and kefir made from them. Jounral of Industrial Microbiology and Biotechnology. 2002. January.