Ian A Reid, (NAGA member since 1991)
Kefir is a slightly effervescent acidulous beverage made mostly from cow’s milk and kefir grains (a yeast/bacterial fermentation starter). Much has been written about kefir. References are provided at the end of the article, in case you want to research the subject in more detail. One reference states that kefir grains involve a community of 30 different types of microbes, including common food fermentation favorites, such as actobacilli, leuconostoc, acetobacter and saccharomyces. So far, nobody has been able to reproduce kefir in the laboratory. Most kefir grains prepared commercially in the US are not made with traditional kefir grains. Instead they are made using starter cultures consisting of some, but not all, known organisms that are part of the traditional kefir symbiosis. Powdered starters approximating kefir are not limited to large scale producers. Several powdered kefir starters are available for small scale home production. Buyers beware. If you want genuine kefir grains, do your research. The laboratory produced starter cultures not only taste good but are beneficial to health. They are not, however, genuine kefir. I’ll list companies that, hopefully, sell genuine kefir grains at the end of this article. It is thought that kefir grains originated in the Caucasus Mountains centuries years ago some say 9000 years ago. Kefir is made today by adding kefir grains to cow, goat or sheep milk.
I use the following utensils: Two one liter bottles, labelled ‘A’ and ‘B’, one strainer, one 2-liter glass container, a couple of spoons and a chop stick. Some authors use wooden spoons and plastic strainers instead of metal ones. I feel that the metal strainer is OK because the kefir is in contact with the metal for such a short period of time.
The picture to the left shows: one fermenting bottle of kefir, utensils (glass bowl, strainer, funnel, chop stick), and half a bottle of ready kefir, half consumed. The picture on the right shows a close up view of fermenting kefir in the left bottle.
When you receive the starter culture follow the instructions to the letter. Raw fresh milk is considered to be the best by some. If you use raw milk; make sure you know the conditions of the source. Raw milk could contain bad bacteria and dirt. Make sure the milk you use isn’t ultra-pasteurized or lactose free. The next best milk is whole milk followed by 2% then skim. When using powered skim milk, be sure to mix it with chlorine free water (boiling water will remove chlorine). For the first week, I use whole milk to get the grains growing. Grains under optimum conditions double in size about every ten days. After a week or so after starting a new batch I switch to powdered skim milk, which I buy wholesale. Skim milk powder has fewer calories than whole milk and seems to work fine. If I see degradation in the kefir quality, I’ll switch back to whole milk for a while.
Steps for Making Kefir
Make sure your two bottles, ‘A’ and ‘B’, and clean and dry.
1. Place a little more than one table spoon of kefir grains into bottle ‘A’, then add the milk to within one inch (2.5 cm) of the top. Give the bottle a shake, then cover the top of the bottle with cheese cloth, or something similar, to let the culture breathe. Place it in a dark corner for 24 hours. Sometime during the day give the bottle another shake to expose fresh milk around the grains.
Tip: Temperature affects the speed of fermentation. A warm environment speeds up the rate of fermentation while a cooler environment slows down the rate of fermentation (It does not matter if your temperature varies during fermentation time between 18C and 30C which gives a wider spectrum of bacterial and yeast growth. A fermentation of a constant 18o C or constant 30o C is not recommended. - source).
2. After the 24 hours, strain the kefir into the glass bowl. Ladle (spoon) the kefir grains left in the strainer into a clean bottle ‘B’ and fill it to within one inch of its top with milk and set it aside for 24 hours. Then pour the strained kefir from the bowl into the first liter bottle, bottle ‘A’. Bottle ‘A’ is kefir that is now ready to drink (sometimes I put some on my fermented cooked steel cut oats to which is added a little turmeric, cinnamon and ginger).
Tip: Often, just before straining the kefir, I notice whey in the bottom third of the bottle. I simply use a chopstick to stir the milk before straining. (After the grains are producing well you could experiment with soy, almond or coconut milk.)
3. The next day, repeat the process for straining, with bottle ‘B.’ Re-use bottle ‘A’ to take the new strained kefir (if you are done with bottle ‘A’), or use a new clean bottle.
Making kefir is a daily chore. Kefir contains large amounts of good bacteria as well as being slightly acid. It’s probably a good idea to consume a small glass at first to see how your body reacts to kefir. When your body reacts favorably increase your daily consumption to say one glass a day. If you need to go away for a few days or weeks, here is what you can do.
Freezing is the best for medium to long term storage of kefir. To freeze, rinse the grains with water and pat dry with a paper towel. Roll them in a bowl of powdered milk. Partly fill a freezer bag with powdered milk and bury the powered milk covered grains into a freezer bag. These grains should last in good condition for six months or more. Another option is to place the grains into a small bottle with a lid and place it in the freezer. I stored mine this way for about 6 months without problems. To store grains for only a day or two, it’s probably safe to simply put the grains into a bottle of cold milk and then into the fridge. A cool environment slows down the rate of fermentation. A web site address is provided, below, for more information on long term storage.
Kefir grains have been around for thousands of years, some sources say for 9000 years. It is thought that the grains originate in the Caucasus Mountains. Many stories have been passed down by word of mouth over the ages about the health benefits of kefir. Traditional kefir is fermented at room temperatures for 24 hours. Fermentation of the milk yields a sour, carbonated, slightly alcoholic beverage. Real kefir grains under the right conditions last a long time, maybe forever. Some authors say that real kefir has to be made at home. Some Suppliers are selling kefir starter cultures that do not have the same qualities as the real kefir grains. These starter cultures are thought to contain fewer of the beneficial bacteria. Some of these powdered started cultures only last for a short period of time according to some suppliers. Costumers of grains must do their homework to make sure you are buying the desired product and not some inferior product.
a. Wikipedia: The article in Wikipedia lists 26 references, plus 2 references for further reading. https://en.wikipedia.org/wiki/Kefir
b. Katz, Sandor Ellix (2012), The Art of Fermentation, An in-depth exploration of essential concepts and processes from around the world. With practical information on Fermenting Vegetables, Fruits, Grains, Milk, Beans, Meats, and more. Published by Chelsea Green Publishing, White River Junction, Vermont.
c. Kefir Kitchen, What is Kefir and How to Make It, They sell what look like real kefir grains, http://www.culturesforhealth.com/starter-cultures/kefir-starter-cultures.htm.
c. Yemoos, Genuine Culture Products and Information. Milk Kefir – Step-by-step Guide.
www.yemoos.com/recommilkefir.html. For these items view Milk Kefir Recommendations.
d. Kefir, Yoghurt for Life, website: http://www.kefir.biz/ferm.htm
edited by Craig Hamm