Read the whole thing, so a fattier milk is better? I've been using cow milk, non-fat. Wondering if I should switch to a 2%+ goat milk. I did get pasteurized, non-homogenized though. The one reason I make/use milk kefir, is because it has the most strains of microbiota (some of which, it seems I learned/read), are only available from kefir made with milk. I've never seen any info that compares the strains/levels of goat vs cow kefir; I don't know if the fat increases or decreases the level or strains. If I were you at this point, I'd go with "whatever you really like the best" (because that's probably what your body needs the most :).
I've rarely been able to get raw milk, so what I usually use is 2% organic, pasteurized, non-homogenized (from one of the best raw/organic small dairies in the nation). When I used whole milk, too much of the fat turned to butter. I didn't discern a difference in the benefits/
Oh yeah, I also use & make it because I'm experiencing/learning how to make various 'kefir cheeses'; kefir makes a FANTASTIC 'sourdough starter'; I can use it instead of buttermilk in my homemade 'Ranch' dressing; and now I can add it to the puppy food I make for our new puppy :)
Also I refrigerate my kefir after it has fermented because I don't like drinking it warm. I also strain with a stainless steel strainer. I think this is one time when plastic is better (for the grains) than stainless. The kefirlady always says she prefers making & drinking it at room temperature, and that's what's best for the grains. I've done mine "every which way". Currently I keep a 1/2 gallon jar in the fridge (sometimes I strain off some of the whey, sometimes not). I use from that jar, and then 'add back' from my current batch. When I'm 'growing grains', I always keep it on the kitchen counter, strain off the kefir whenever it's 'ready', add fill the jars back up with room-temp milk. And occasionally I rinse/soak the grains in whey to get off all the milk-fat buildup. But for 'everyday use', almost the whole process is 'refrigerated' (because they'll eat me out of house & home if I don't 'slow them down'). However, every 7-10 days (or whenever they appear to be 'slowing down too much'), I take them out and give them a half day/day at room temp with fresh milk.
Real good info, i'm going to up my kefir consumption after reading this, and try mixing stuff into the kefir when I drink it. One of my absolute favorites is bee pollen, honey & kefir. The 'goodness' is phenomenal.
Still unsure what to taste for when looking for proper kefir. I usually wait til it starts to separate then consider it done. By that point it's not bubbly like when I drank it before the separation. That is the natural & normal progression of kefir, as I know & understand it. The levels of the various microbiota change (some substantially), as the levels of lactose changes. I drink it in all the various stages. I like it best 'straight' at it's fizzy stage, but thicker & more 'sour' when I'm mixing it with other stuff.
Let us know what you come up with for kefir blends :)