It is absurdly simple:
- Source some Kefir grains - Craig's List, Amazon, specialty Kefir sites, neighbors, friends
- Place grains in a jar and fill jar with milk
- Cover jar to keep dust off (I use a coffee filter secured with a rubber band)
- Every couple of days scoop them out of the jar and put in a clean jar with fresh milk
- The milk left over has miraculously turned to Kefir
There are a few 'tricks' to keep in mind:
- Wash hands and keep things clean so you don't contaminate the culture
- When they start getting too active divide the grain population in half - you can eat the discarded grains or feed them to the chickens - I rather like them so I tend to eat them myself
- If your grains are traumatized - like when you first get them, or if you neglect them, you can revive them by putting them in milk until they perk up again
- I find it easier to fish them out if they are in a container - I use little bamboo baskets from Thailand because Kefir doesn't love metal and you need big holes so the milk flows over them - I just find it a lot easier to fish out a basket than it is to skim for the grains
Over time you will learn what consistency and degree of sourness you like - the longer you leave them the more it will turn into cheese and the more sour it will taste.
Here is a link to a Kefir site that explains it - and really it is even simpler than they say here:
https://www.culturesforhealth.com/learn/milk-kefir/how-to-make-milk-kefir/
And here is a link to Amazon site for Kefir grains - you can get them cheaper for sure - if you check Craig's list people even give them away because they multiply so fast (it is a bit like us with eggs in spring!) - but this one comes with an e-book on how to do it if you never have
https://www.amazon.com/gp/product/B007GGRJTG/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
I find the grains are pretty tough - they freeze well (I have used grains that were frozen for 3 years), and even when I neglect them badly they can always be nursed back to life. The only time I have thrown any away is once I got black mold on the Kefir and that felt like something I wasn't comfortable dealing with!