In my introduction to lacto-fermentation I mentioned the use of live whey from kefir. About one person in a hundred that I know or speak to has heard of kefir, let alone made use of it, so here goes from me.
Kefir is made by fermenting milk using an ongoing culture, known as kefir "grains". According to the enthusiasts, kefir is extremely nutrient dense, full of probiotics, and very, very healthy, as well as having a very small curd that is very easy for lactose-sensitive persons to digest. Kefir is also brimful of vitamins like B12 which can be difficult for vegetarians to obtain in quantity.
Kefir comes in two forms, as "grains", passed from hand to hand privately, and as a commercial product available in New Zealand as "Kefir starter culture".
(Its pronunciation comes in half a dozen forms. I prefer "kuh-feer".)
Kefir 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 or more across.
You cannot make the "home brew" form without the grains, which have been passed on from person to person over hundreds of years. As we feed them daily milk and harvest the kefir, the grains increase in quantity, and we can in turn pass them on to someone else.
At this stage in New Zealand grains are not always easy to come by. They used to be available on TradeMe, but Trademe has now banned their sale unless one can prove they were produced in a kitchen of commercial standard, and comply with all relevant New Zealand government regulations for the production and sale of foodstuffs. This effectively removes kefir as an item that can be listed on Trademe.
Sometimes, your nearest healthfood shop may have a list of local kefir sources.
I tried sending some to a friend in Napier. I put the grains and a supply of milk in a small but sturdy sealed plastic container, inside a sealed plastic bag. I placed the bag in a larger plastic container, packed around with newspaper, and wrapped the larger container in several layers of newspaper before enclosing it all in a sealed plastic bubble bag for the courier. It arrived alive, just, but with the outer and innermost solid plastic containers broken. It's a p.i.t.a. and I no longer try posting it.
Each day, you strain your fermenting kefir, retain the grains, and use the kefir for whatever you have in mind:
- as a drink, either by itself or mixed with milk.
- as an ingredient in breadmaking or baking
- to make a ricotta like soft cheese by straining the whey off the curd
- using the whey as part of a starter solution for sauerkraut or other lacto-fermented products.
- with cream to make something very close to creme fraiche
The grains are added to fresh milk in an opaque, lidded (but not sealed), non-metal container, (E.g., a stoneware 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 (max 1.5-2%) curds and whey combination. (Questions: Was Miss Muffet a kefir fan? Was the prophet (p.b.u.h.) an alcohol fan?) Experiment to get the particular combination you want.
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, sharper and more "cheesy".
I discovered, however, that if I mixed the sharper kefir with straight milk, about 50-50, I was once more getting the milk drink I started out with, still fresh and sharp but nowhere near as intense. Alternatively, strain off the kefir grains as soon as junket stage is reached, before the curds and whey form. In summer in New Zealand this time can be as brief as 3-6 hours after adding fresh milk.
If your kids find milk a trifle fatty or greasy, the slight sharpness from kefir or a kefir blend is something they may go for. It's also more easily digested. It does leave a wonderful white moustache, even better than milk, which 8 year olds will appreciate.
I generally make about half a litre of kefir each day for myself, most of which goes into kefir ricotta or bread. In summer I am more likely to mix it with milk for a refreshing drink. Once it is strained off the grains, I store it in a pottery or glass container in the fridge until needed. It will tend to become slightly sharper over several days of storage.
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, though personally I don't find them especially palatable.
Remember, your kefir grains are alive, a symbiotic (mutually dependent) community of yeast and bacteria, and require to be fed, daily. If they are not fed they will die. If you are going away for up to a fortnight, they can be stored in milk in the fridge, whereupon the whole process goes into a kind of hibernation. When you get back, if it's just been a day or two, strain the grains from the kefir as you would normally. If it's been longer - a week or more - strain off the liquid and discard it. Rinse the grains in preferably non-chlorinated, non-fluoridated water, shake excess water free in a strainer, and return to a washed and dried fermenting container with fresh milk.
It can sometimes take a little time to get your new "grains" into full production. Your starter kit of about a dessertspoon of grains is sufficient initially to ferment about a cup of milk. 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 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. If you like you can dilute the cream with up to one third milk for a slightly thinner result.
Kefir Ricotta: I start with a litre of kefir and generally obtain about 250g ricotta. Start with a large non-metallic bowl, and place inside of that a stainless steel or plastic colander. Line the colander with a double thickness of clean teatowel and pour in your kefir. Cover with a dinner plate and place somewhere cool, not cold. Leave for 18-24 hours, then scrape the ricotta from the teatowel into a lidded non-metallic container and store in the fridge.
In the bottom of the bowl there will be a slightly cloudy whey, which can be discarded, or which can be used as part of a lacto-fermentation process. I make my own sauerkraut and kimchi (nowhere near as blisteringly hot as the genuine article) as well as pickling other vegetables such as carrot, beetroot, etc. The whey can be drunk directly, and is highly nourishing, but I think it is perhaps an acquired taste. It can also be used in making "kvass", or beetroot "kvass", a favourite beverage in Russia and Eastern Europe, also an acquired taste, though not unpleasant.
Sauerkraut or kimchi or other pickles combine well with the ricotta along with a cracker or piece of toast for a healthy snack.
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:
- yeasts, and
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 portion of the last brew to a fresh supply 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.
I have preferred on the whole to stay with the kefir grains, after exploring both, but taste-wise there is little difference, and if you simply can't find the grains, this is at least some of the way towards your goal.
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)
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
[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]
Lb. brevis [Possibly now Lb. kefiri]
Lb. casei subsp. casei
Lb. casei subsp. rhamnosus
Lb. paracasei subsp. paracasei
Lb. delbrueckii subsp. bulgaricus
Lb. delbrueckii subsp. lactis
Lb. helveticus subsp. lactis
Lb. kefiranofaciens subsp. kefirgranum
Lb. kefiranofaciens subsp. kefiranofaciens
St. paracitrovorus ^
Lactococcus lactis subsp. lactis
Lc. lactis subsp. lactis biovar. diacetylactis
Lc. lactis subsp. cremoris
Leuconostoc mesenteroides subsp. cremoris
Leuc. mesenteroides subsp. mesenteroides
Leuc. dextranicum ^
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
Kluyveromyces lactis var. lactis #
Saccharomyces cerevisiae #
Sacc. subsp. torulopsis holmii
Sacc. turicensis sp. nov
Torulaspora delbrueckii t
* Zygosaccharomyces rouxii
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.
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 cup of kefir to replace a half cup of water in the recipe, again with excellent results. The bread is a little softer, and keeps longer. My experiments suggest that the liquid content of a batch of bread dough should be a maximum of 50% kefir, after which I suspect the acidity of the dough increases to a point that slows down fermentation.
Stoneware: Low-fired or earthenware glazes are softer, and more likely to contain toxic ingredients which may leach out with prolonged exposure to even mildly acid food stored in them.
Caring for your new kefir starter
(Click on the heading for a doc file which you can download)