On Sun, Jul 08, 2007 at 01:31:34PM -0400, Angelo wrote: <Snip> Nope -- yogurt is made at high temperatures (around 115F-120F if I remember correctly) and takes only a few hours. Kefir is made at room temperature and takes 12-24 hours, so a yogurt maker wouldn't work at all. I find kefir is best made even a bit cooler than normal room temperature. Mine comes out best during the winter, when "room temperature" in my house means around 66F. In the summer it's around 78F and that's a bit too high for kefir, so I put it in the refrigerator for part of the fermentation period. Making kefir is easier than making yogurt in my experience, because everything happens at room temperature and you don't need to sterilize your utensils -- the symbiotic kefir organisms form a rather stable culture and will fight off contaminating organisms like E. coli and salmonella, so long as the bad organisms aren't given a head start. (This has actually been shown in lab experiments.) I should caution, though, that such things are never completely reliable, and if you have a weakened immune system for any reason, I'd stick with store-bought kefir. The basic process is that you take the kefir "grains" -- which look a bit like tiny clusters of cauliflower or ocean coral -- and put them in milk in a non-reactive container (glass jar). No need to boil or sterilize anything, but everything should be clean. You leave that for 12-24 hours until it thickens, strain out the grains, put the kefir in the refrigerator, and start another cycle by putting the grains you strained out in fresh milk. The grains are actually a community of yeasts and bacteria living on a polysaccharide substrate that they construct themselves (a little like ocean coral), and they will grow and "bud" over time, so you end up having extra grains to give to friends, throw away, or you can do what I do -- eat them. If anybody wants a source of grains, I can recommend the woman I got mine from:http://www.kefirlady.com/. I can also send some to you for the cost of postage, though you'll have to wait until I have some extra to get rid of. Marilyn (at the above link) keeps plenty growing and ships weekly. (I have no affiliation with her.) References, lest you think I'm making this up:  Santos, A., San Mauro, M., Sanchez, A., Torres, J.M. and Marquina, D. 2003. The antimicrobial properties of different strains of Lactobacillus spp. isolated from kefir. Systematic and Applied Microbiology 26: 434-437.http://scholar.google.com/scholar?clusterP20253246415814592See also: http://www.foodsciencecentral.com/fsc/bulletin-ff-free
On Sun, Jul 08, 2007 at 01:11:27PM -0500, Rich Adams wrote: <Snip> Yeah, that's Dom's kefir site. Dom is to kefir what our Tom is to home roasting, except that Dom comes off to me like a rambling, new age lunatic most of the time. Which is not to say that he doesn't know his stuff! There is a lot of good information on that site, if you can sort through all the mess and wacky grammar to find it. But in the end, kefir is very simple, and there's way more information on that site than you really need to make kefir. For the more obsessive folks (and we don't have any of those here...) it's a great site to pour over. <Snip> They haven't been made in a lab *yet*, which I suspect is probably for lack of any serious effort to do so, because it's rather easy to just procure them from other kefir makers instead. But the straightforward method of just taking brewed kefir (or organisms isolated from it) and trying to keep propagating the culture in the hope that the kefir grains spontaneously form does not actually work. Nobody has figured out yet how to "seed" the grains so that they will start growing and reproducing. But obviously, it happened at least once, long ago, and probably quite by accident. Like with our friend Kaldi and his goats.
On Sun, Jul 08, 2007 at 11:53:47AM -0700, Lisa Carton wrote: <Snip> A few tips for you and others who might decide to give it a try: Marilyn is very good about providing support for people who buy grains from her, but you can feel free to ask me any questions as well. Marilyn's personal experience is limited to her own use of the raw milk from the goats she raises herself, and I think that's a bit different than using pasteurized cow's milk from the grocery store. In particular, I end up using a smaller amount of grains than she recommends, but that also depends a lot on room temperature wherever you are. Your first batch probably will not taste very good, until you figure out the right combination of grains-to-milk ratio, temperature, and time. Kefir is also somewhat of an acquired taste for some people, but it is tweakable to individual tastes (much like coffee). Letting the kefir "ripen" in the refrigerator for a day after brewing usually makes it a little smoother and more palatable -- so you always have one jar brewing at room temperature and another jar (strained) ripening in the refrigerator. On the other hand, now that I've got it figured out, I really love taking a few swigs of kefir immediately after straining -- it's so buttery and creamy and delicious right then. If the kefir solidifies into curds, it can be hard to strain out the grains -- in this case, cap the jar tightly, shake well to break up the curds, then strain it, using a spatula to scrape the sides of the strainer to help it along. In the summer, my kefir spends half its time in the fridge: 12 hours at room temp, then 12 hours in the fridge, then strain and repeat with fresh milk. In the winter it stays at room temperature all the time. It is hard to kill kefir grains (unless you cook them -- never use hot milk), but it's easy to get them "unbalanced" so that they don't ferment well or produce overly cheesy or sour kefir. Regular changes of fresh milk at room temperature (with time in the refrigerator) will usually get them back in shape in a few days. Use any nasty kefir they make while "sick" to make kefir cheese, pancakes/bisquits, fruit smoothies, etc. Lots of ideas for that sort of thing on Dom's site.