Kefir

From Wikipedia, the free encyclopedia

Kefir (alternately kephir, kewra, talai, mudu kekiya, waterkefir, milkkefir, búlgaros) is a fermented milk drink originating in the Caucasus.

This drink is prepared by inoculating cow's or goat's milk with the grains - or "beads" - of previous kefir batches. Kefir grains are a combination of bacteria and yeasts in a matrix of proteins, lipids and sugars. Lactobacillus acidophilus and Saccharomyces kefir are widely used, though the exact combination of bacteria and yeasts vary between cultures. The milk is incubated at room temperature for a day or more, during which the lactose is fermented. The resulting beverage is a sour, carbonated, slightly alcoholic drink. The consistency is similar to thin yoghurt. In fact, most commercially available American "kefir" lacks both carbonation and alcohol and is nothing more than liquid yogurt. Other places may have both alcoholic and non-alcoholic kefir.

Variations that thrive in various other liquids exist. They may vary markedly from kefir in both appearance and microbial composition. Water kefir (or kefir d'acqua) is grown in water with sugar, dry fruit such as figs and lemon juice for a day or more at room temperature.

Because of the small amount of alcohol in kefir, some believe that it is a hangover cure in the style of "hair of the dog".

1 Making Kefir
2 Health Benefits
3 Drinking Kefir
4 Different milk types
5 Bibliography
6 External links

[edit] Making Kefir

Image:Kefir-grains-90grams.jpg

Making kefir requires a live culture of bacteria and yeasts. This culture can be bought in the form of a starter kit or can be acquired as a "chunk" from another culture. This bacterial culture forms a rubbery feeling lump that can look like a small floret of cauliflower and ranges in size from a small kernel of corn to a small plum. As you make more kefir, this culture will grow in size. Eventually, you will be able to split the culture in two. It is then possible to make two batches at once, dehydrate one portion for storage, or give it to a friend. Commercially available, bottled kefir and powdered starter cultures containing some of the bacteria and yeasts isolated from the kefir lump, or "mother grain", will not spontaneously generate lumps or "mother grains". The lumps will only multiply from existing lumps. Kefir grains will exude a clear or pale yellow gel called kefiran at certain stages of growth which is normal and contributes to kefir's organoleptic (mouthfeel) properties.

The kefir lump tends to float in your fermented milk and can be scooped from the surface before drinking the kefir and making a new batch. It is okay to transfer some of the fermented milk to the next batch of kefir. Wash out your kefir-making container between batches. Washing the kefir culture, especially in normal tap water, is not recommended.

Many variations of the simple method exist. Different individuals will assert that one way is better than another; however, different bacterial cultures are present in different quantities during the fermentation of the milk. For this reason there is no "correct" method of making kefir so long as the culture is kept alive.

Depending on the volume of milk and the size of your kefir culture, your milk will ferment into a jelly or thin yoghurt over the course of 12-36 hours. More bacteria and less milk tend to make this fermentation happen faster. Kefir separates into lumps (cheese curds)and a thin straw colored liquid (whey) when left for long durations. This is not ideal for drinking but it is possible to form a soft cheese with it.

Room temperature or slightly warmer is ideal for making kefir. Making kefir in an old jam jar or pickle jar works well. Fermentation creates carbon dioxide and as a result, a tight fitting lid can cause a buildup of pressure. Keep your kefir out of direct sunlight. The top of a warm refrigerator or a cupboard above the stove are ideal places to keep it. Keeping your culture out of contact with metal utensils is also recommended. Otherwise, the acidity of a kefir culture can allow metal residues to get into your body. Stainless steel is unlikely to cause any trouble but glass and plastic are preferable. In warm to hot climates, it is best to put the culture into the refrigerator during the day and on the counter top at night, to help regulate the temperature.

Taking a break from making kefir is easily done. Instead of leaving the culture at room temperature, put it in the refrigerator before it is allowed to begin fermenting. When ready to make kefir again, remove it from the refrigerator and your culture will begin to grow. This will not work indefinitely. For longer storage or to create a backup supply of kefir, the lumps can be washed in preboiled cold water, dehydrated at room temperature for a few days and then stored in an airtight bag in the refrigerator. These dehydrated grains will be yellow in color and can be stored for many months. Reactivating dehydrated kefir is done by starting to make kefir using the normal method. This will not produce normal kefir for a few days. Cycle the milk every day but don't drink this kefir until it looks and smells like normal. This re-growth stage is required to re-establish the correct bacterial balance within the culture.

See also: kumis, ayran, lassi, tibicos, kombucha and other dairy products.

[edit] Health Benefits

Kneifel and Mayer (1991) found that appreciable amounts of pyridoxine, vitamin B12, folic acid and biotin were synthesized during kefir production, depending on the source of kefir grains used, while thiamine and riboflavin levels were reduced. These results contrast with Alm (1982b) who reported decreases in biotin, vitamin B12 and pyridoxine, and significant increases in folic acid, as compared to non-fermented milk. Kefir has had a long history of being beneficial to health in Eastern European countries, where it is associated with general wellbeing. It is easily digested (Alm 1982c) and is often the first weaning food received by babies. Many of the studies regarding health benefits of kefir have been published in Russian and Eastern European journals and therefore are not easily accessible to Western science (Batinkov 1971; Ormisson and Soo 1976; Evenshtein 1978; Safonova et al. 1979; Ivanova et al. 1981; Sukhov et al. 1986; Besednova et al. 1997; Oleinichenko et al. 1999). However, the health benefits of kefir were demonstrated in Canada as early as 1932 (Rosell 1932).

[edit] Drinking Kefir

While some drink kefir straight, many find it too sour on its own and prefer to add fruits, honey, maple syrup or other flavors or sweeteners. Frozen bananas, strawberries, blueberries or other fruits can be mixed with kefir in a blender to make a smoothie.

[edit] Different milk types

Kefir grains will successfully ferment the milk from most mammals, and will continue to grow in such milk. Typical milks used include cow, goat, and sheep, each with varying organoleptic and nutritional qualities.

In addition, kefir grains will ferment non-mammal "milks" such as soy milk, rice milk, and coconut milk, as well as other sugary liquids including fruit juice, coconut water, beer worts and ginger beer. However, the kefir grains generally cease growing in these liquids, so it is best to only use excess kefir grains for these ferments.

Soy milk is an exception - kefir grains will reportedly [1] continue growing in soy milk, but will turn a pale yellow and reduce to the size of a pea.