Home-made Kefir – an ongoing adventure
Many years ago, when still living in Germany, I used to like kefir with my muesli in the morning. In Germany you can buy it in the dairy section of your local supermarket. However, this is not necessarily the case in other countries, and I sort of forgot about kefir. It was only when researching the history of cheese that I was reminded of it.
In the beginning of September, while walking through our local shopping centre, I saw a sign at the chemist’s advertising kefir starter kits. I was intrigued and bought one. It contained a little bag of dried kefir bacteria, similar to dry yeast, which you mix with milk, leave standing at room temperature and 24 hours later you have kefir. It tasted quite nice, but my curiosity was tickled. As you do, I started trawling through the internet and soon found that kefir grains, not the powdered stuff, are the real thing.
Kefir is a mildly acidic fermented milk drink. Kefir grains are added to milk, left for 24 hours to ferment at room temperature, and the next day you can enjoy kefir. I have only used cow’s milk, but milk from any kind of mammal can be used, or even soy milk (though the grains seem to grow more slowly ). Not having easy access to a dairy farm and raw milk, I have only used homogenised and pasteurised fresh milk from a supermarket.
It is said that the term kefir is derived from the Turkish word kef, meaning ‘pleasant taste’. Its flavour comes from a blend of lactic acid, ethanol, carbon dioxide and flavouring products, such as acetaldehyde and acetoin. The carbon-dioxide makes it slightly fizzy, drinking it feels a bit like drinking champagne. However, it not only tastes pleasant it also has a variety of health benefits, such as antimicrobial, immunological, anti-tumour and hypocholesterolaemic effects. The microorganisms in kefir produce vitamins, degrade protein and hydrolyse lactose, resulting in a highly nutritious and digestible foodstuff, which is said to be also suitable for people who are lactose intolerant.  With its large number of different bacteria and yeasts, it is a very complex probiotic. Its probiotic complexity makes all the difference when it comes to health benefits, as most commercially available probiotics contain only a very limited variety of bacteria. 
It is quite awe-inspiring to think that my kefir grains are the descendants of those cultures discovered thousands of years ago. As one writer said, “Kefir’s millennia-old cultural lineage puts 100-year-old sourdough starters to shame”. As I also bake our bread with sourdough (which is not even close to 100-year-old), this image appeals to me. The origin of Kefir grains is as yet unknown. There are stories that the people in Central Asia kept kefir as a continual fermentation in a dried sheep’s stomach hanging from the rafters of a yurt, just adding milk. 
Of course, I don’t have a sheep’s stomach hanging from the rafters of our house. The present day home-kefir-maker can use utensils which are readily available in many shops. My equipment consists of:
- a 1l glass mason jar with a separate disc-shaped lid and a screw-on ring (available for preserving food) in which the kefir is fermented
- a piece cheesecloth, for covering the milk and kefir grains mixture in the jar while the kefir is fermenting, this is fastened to the mason jar with the screw-on ring
- a teaspoon with a long handle, for stirring the kefir grains and the milk
- a stainless steel sieve, for straining the kefir grains from the kefir once it is fermented
- a large, wide-mouthed measuring jug (wide enough to fit around the sieve), into which the kefir can be strained and then easily poured into a storage jar
- other mason jars, for storing the kefir in the fridge until it is used (the type of lid does not matter as long as it is airtight)
According to the experts, plastic containers and utensils are not advisable, as they may leach chemicals into the kefir. Metal containers are also not recommended, but stainless steel utensils, like the spoon and sieve, are okay, as the kefir is exposed to them only for short periods. 
As (good) bacteria are needed for the fermentation process, you should not wash your utensils too enthusiastically with (antibacterial) washing-up liquid. Hot water and a good bottle brush for the jars will do the trick. I have a bottle “brush” which has a tip made out of spongy material, which is ideal for the job – and I keep it exclusively for my kefir jars.
David Asher suggests using kefir as a starter to make yoghurt and cheese. So far, I have not experimented with using kefir in this way, but that has been more due to lack of time rather than lack of inclination. Except for having kefir with muesli, I have also used it – mixed with fresh herbs – as a sauce with fish.
My experience with making kefir has been very positive, it is easy to do, is good for you and it is fun. As long as you can get hold of some kefir grains, there shouldn’t be any problem. As the grains multiply naturally when being used, most kefir makers are only too happy to share them with a novice kefir maker. There are also people who sell them online, which is where I got mine.
Good luck and bon appetit!
Notes and References:
- Farnworth, E.R., ‘Keﬁr – a complex probiotic’, Food Science & Technology Bulletin: Functional Foods, Vol. 2, No.1 (2005), pp.1–17 [last accessed online 2 Sept. 2015]
- Arslan, S., ‘A review: chemical, microbiological and nutritional characteristics of kefir‘, Journal of Food, Vol. 13, No. 3 (2015), pp.340–345 [last accessed online 11 Oct. 2015]; and Adriana, P. and Socaciu, C., ‘Probiotic activity of mixed cultures of kefir’s lactobacilli and non-lactose fermenting yeasts‘, Bulletin UASVM, Agriculture, Vol. 65, No.2 (2008), pp.329-334 [last accessed online 2 Sept. 2015]
- Asher, D., The Art of Natural Cheesemaking: Using Traditional, Non-Industrial Methods and Raw Ingredients to Make the World’s Best Cheeses. Chelsea Green Publishing, 2015, pp.86-87
- Asher, D., p.86
- Asher, D., p.90