Growing up I told people I was allergic to milk because I just didn't like the taste. Today I buy, on average, two gallons a week. My change in attitude can be attributed to a gift of kefir grains.
I never say no when someone wants to give me an edible that they love. At the time, I didn't know what kefir grains were. I'd seen kefir in the stores and was interested in trying it, but never got around to making the purchase. After receiving the grains, I bought raw milk from Ty Llwyd Farm. I put the milk in a covered container, added the grains, put the container in my basement refrigerator, and left them there for perhaps a year. That's way longer than recommended but I find kefir grains to be remarkably resilient.
I had no idea how kefir should taste so I just jumped right in. I bought more milk, retrieved the grains from the refrigerator, and plopped them into the milk. The grains had gotten quite large so I wasn't concerned that they had lost any potency but I really didn't know what I was doing. After a day or two, I strained the kefir and tasted it. And wondered if that was how it was supposed to taste. I repeated the feeding a few more times until I tasted the kefir and a lightbulb went off in my head. This was how it was supposed to taste. I just knew it was right. It was a bit bubbly and I liked it.
If you want to get started with kefir, find someone who makes it. If you've never had it, you'll find out firsthand how it should taste. And most people who make kefir have enough kefir grains to share. I know I have plenty to share. Kefir grains are pretty hard to kill as I learned when I ignored them in my basement refrigerator.
It only takes a spoonful of grains, a quart of milk, and a day on the countertop to make kefir. Don't get hung up on the amount of time, go by the consistency of the kefir. Depending on the grains and the ambient temperature, it could take more or less time. You don't have to let it ferment on your countertop. Fermentation will slow down in the refrigerator. And I find that refrigerated kefir gets more bubbly. And I like that.
Do a second ferment. Or not. After I strain out the kefir grains, I add a sweetener to the kefir and let that ferment for another day or more. The grains get added to more milk and the cycle continues.
I don't tell people I'm allergic to milk these days but I still don't drink it. I am a big fan of kefir however.