Kefir is a yoghurt-like drink made by fermenting milk. According to the enthusiasts, it is extremely nutrient dense, full of probiotics, and very, very healthy, as well as being very easy for lactose-sensitive persons to digest. It is also brimful of vitamins like B12 which can be difficult for vegetarians to obtain in quantity.
It comes in two forms, as "grains", and as a commercial product or starter culture.
(Its pronunciation comes in half a dozen forms. I prefer "kuh-feer".)
Grains
The grains originate from Muslim communities in the Caucasus. Their origin is uncertain, but legend maintains they were a gift from the prophet himself (p.b.u.h.). The grains are alive, a symbiotic combination of yeasts and lactic acid bacteria, and they feed off the lactose in the milk. They resemble rubbery cauliflower florets, up to an inch across
First you need to obtain your grains. At this stage in New Zealand they are not easy to come by, but they are often available on Trade Me. You cannot make the "home brew" form without the grains, which have been passed on from person to person over hundreds of years. (An email to me will tell you whether I currently have spare grains available.)
Each day, you strain your fermenting kefir, retain the grains, and drink the liquid, or use it in any of a number of ways that yoghurt enthusuasts will recognise. The grains are added to fresh milk in an opaque, lidded non-metal container, (E.g., a pottery casserole) and here's where it begins to get a little complicated.
Depending on the ratio of grains to milk, the temperature of fermentation, and the time allowed you can get anything from a slightly spritzig junket to a sharp, cheesy, effervescent and mildly alcoholic curds and whey combination. (Question: Was Miss Muffet a kefir fan?)
I described kefir as a "drink" earlier, and yes, that was the case with the kefir I made over the winter, but as the weather became warmer, and my kefir grains increased in quantity, the kefir became somewhat less palatable, and I mainly used it as an ingredient in my daily bread-baking.
I discovered, however, that if I placed the kefir grains and milk in the fridge, increased the milk content a little, and left them for several days, I was once more getting the refreshing "junket"-like drink I started with in the late winter.
With each successive brew the grains grow slightly, and in time, you have enough to increase the amount of kefir you brew, or you can pass the extra grains on to somebody else, a bit like the traditional ginger beer plant. You can also eat the grains, if you wish.
It can sometimes take a little time to get your new "grains" into full production. My grains were bought off Trade Me, and it took about a month to grow them to useful volume. The early samples of kefir I have obtained from them have been delicious, though without the smooth creaminess of the commercial form. (But much better for me, so my sources tell me.)
| Creme Fraiche: For a much cheaper home-made and delicious creme fraiche, add about a tablespoon of "grains" to 300ml of cream, and place them in the fridge in a lidded, opaque non-metal container for several days. The cream will semi-solidify into creme fraiche, and when it has, simply return the grains to your milk culture until needed once more for higher purposes. I have used this also as a sour cream substitute in making quiches and various egg and cheese dishes. |
Research suggests that "grain" kefir cultures contain a wide variety of organisms, and vary somewhat from one culture to another.
Typically, "grain" kefir will contain organisms from four different groups:
- Streptococci/lactococci,
- lactobacilli,
- yeasts, and
- acetobacter.
The commercial culture below contains only organisms from the streptococci/lactococci group
Commercial Kefir or Kefir Starter Culture
In a nutshell, the commercial version is a compromise,
Unfortunately, according to the home brew enthusiasts, in the process of getting it on to supermarket shelves in standardised form, or preparing commercial starter cultures to the same end, many of the health benefits accruing from the original multi-organism "home-brewed" kefir are sacrificed.
There are in fact a number of commercial versions. At present, as far as I know, it is not possible to purchase kefir from a supermarket in New Zealand, but a commercial starter culture, XPL-1, can be ordered from Curds and Whey, an online business in Auckland specialising in cheese-making supplies.
This culture is extremely concentrated, and though a packet of the culture plus shipping in New Zealand come to just under $50, the several teaspoons of granules - a bit like powdered milk granules in appearance - are sufficient to culture 250-500 litres of kefir.
These granules have a fridge life of around two years. Not only that, but if you add a cup of the last brew to a couple of litres of milk, 24 hours later you have a fresh brew of "commercial" kefir for the cost of the milk, and requiring no extra granules. I am presently (3 November 2009) on my 30th or thereabouts generation of "commercial" kefir from the original 4 or 5 granules, with no deterioration in flavour or texture.
(This is a bit of a plus compared with supermarket yoghurt cultures like EZI-YO or Hansell's, which rapidly become sharper and thinner if you use some of the product to start the next batch.)
This XPL-1 product generates no "grains", yet obviously is sufficiently "alive" to grow new batches. With a lid on, it also becomes slightly effervescent. So we are not, here, dealing with the gas-free commercial product found in supermarkets overseas, but neither are we dealing with the grain-producing "home brew" form, or as its enthusiasts refer to it, "real kefir".
The CHR-HANSEN website appears to be constructed by PR and marketing people whose purpose is not to inform so much as it is to create an "ambience", and detailed information on organisms present in the culture was not directly available. However an email to the company returned a prompt reply. (See below.)
The product is simple to prepare, delicious, and, as with grains, about a quarter to a third the price of commercial yoghurt. Once you have the culture, the cost is simply whatever you pay for the milk you use. I suspect you could probably safely split the cost of a sachet between 2-3 people, and still have plenty of culture to start with and also for insurance purposes.
Information
Once you start looking there are dozens of internet sites ranging from downright precious right through polysyllabic academic. Library books are fairly sparse when it comes to information on the subject. Even Auckland Public Library boasts only two books, and neither is specifically devoted to kefir.
It's got a way to go before it gets to be as mainstream as yoghurt.
I'd check out the Wikipedia page for possibly the best straightforward account, and from there a number of links are provided to other information sources, both technical and evangelical. Another excellent site is http://www.kefir.biz.
For an enthusiast's site, check out Dominic's comprehensive (and how) site at http://users.chariot.net.au/~dna/kefirpage.html
There are also a couple of other related products, kombucha and water-kefir, which I will write about when I have got my head around this lot.
Microorganisms present in CHR Hansen culture XPL-1 (email from CHR Hansen)
Streptococcus thermophilus
Leuconostoc species
Lactococcus lactis subsp. lactis biovar diacetylactis
Lactococcus lactis subsp. lactis
Lactococcus lactis subsp. cremoris
Microorganisms Found in Different Batches of Milk Kefir-Grains and Kefir
from http://users.chariot.net.au/~dna/kefirpage.html#composition-of-KG
[Note: By no means all of these organisms are present in any given "grain" culture kefir. DCW]
Divided into Four Genus Groups [with revised nomenclature]
LACTOBACILLI
Lactobacillus acidophilus
Lb. brevis [Possibly now Lb. kefiri]
Lb. casei subsp. casei
Lb. casei subsp. rhamnosus
Lb. paracasei subsp. paracasei
Lb. fermentum
Lb. cellobiosus
Lb. delbrueckii subsp. bulgaricus
Lb. delbrueckii subsp. lactis
Lb. fructivorans
Lb. helveticus subsp. lactis
Lb. hilgardii
Lb. helveticus
Lb. kefiri
Lb. kefiranofaciens subsp. kefirgranum
Lb. kefiranofaciens subsp. kefiranofaciens
Lb. parakefiri
Lb. plantarum
STREPTOCOCCI/LACTOCOCCI
Streptococcus thermophilus
St. paracitrovorus ^
Lactococcus lactis subsp. lactis
Lc. lactis subsp. lactis biovar. diacetylactis
Lc. lactis subsp. cremoris
Enterococcus durans
Leuconostoc mesenteroides subsp. cremoris
Leuc. mesenteroides subsp. mesenteroides
Leuc. dextranicum ^
YEASTS
Dekkera anomala t/ Brettanomyces anomalus a
Kluyveromyces marxianus t/ Candida kefyr a#
Pichia fermentans t/ C. firmetaria a
Yarrowia lipolytica t/ C. lipolytica a
Debaryomyces hansenii t/ C. famata a#
Deb. [Schwanniomyces] occidentalis
Issatchenkia orientalis t/ C. krusei a
Galactomyces geotrichum t/ Geotrichum candidum a
C. friedrichii
C. rancens
C. tenuis
C. humilis
C. inconspicua
C. maris
Cryptococcus humicolus
Kluyveromyces lactis var. lactis #
Kluyv. bulgaricus
Kluyv. lodderae
Saccharomyces cerevisiae #
Sacc. subsp. torulopsis holmii
Sacc. pastorianus
Sacc. humaticus
Sacc. unisporus
Sacc. exiguus
Sacc. turicensis sp. nov
Torulaspora delbrueckii t
* Zygosaccharomyces rouxii
ACETOBACTER
Acetobacter aceti
Acetobacter rasens
Legend
t Teleomorph. Sexual reproductive stage. Yeast form pseudo-mycelium as in Flowers of Kefir.
a Anamorph. Asexual reproductive stage. Reproduce by budding or forming spores or cell splitting [fission].
# Can utilize lactose or lactate.
^ Aroma forming.
subsp. Sub specie type.
sp. Specie type.
sp. nov. New strain or new specie strain type.
biovar. Biological variation strain type.
var. Variety type. |
Recipes
Cream Kefir: What happens if you put some commercial culture kefir (see above) into a pot of cream? [Whoops. I've just reinvented creme fraiche. True. Except the recipes tell you to use buttermilk, not kefir. DCW]
Velvet Salad: Now that I've got some fermented cream, what are the possibilities?
Breadmaking:
I'm currently experimenting with using kefir in breadmaking. So far, wherever a recipe has called for yoghurt or milk to be added to the dough, I have added kefir for excellent results. In other loaves, I have added about 1.5 cups of kefir to replace a cup of water in the recipe, again with excellent results. The bread is a little softer, and keeps longer.
