1 quart whole milk (goat, sheep or cow) ~2-3 Tbsp active milk kefir grains
Pour the milk into a clean glass jar and stir in the kefir grains. Cover with a Kefir Cap, loose lid or muslin cloth (a tightly-woven cheese cloth) secured with a rubber band. Let sit out at room temperature, out of direct sunlight. Check the jar after 12 hours. Swirl it around. When the milk has thickened, smells & tastes sweet & tangy, it's ready! This will take anywhere from 12-36 hours. Fermentation time depends on the activity & strength of your culture, the ratio of grains to milk and the ambient temperature. Warm temperatures speed up fermentation, cold temperatures slow it down.
When fermented to your desired thickness, place a small strainer (or use the built in strainer in the Kefir Cap) over another clean jar. Strain the kefir into the clean jar, catching the grains in the strainer. (Sometimes the thickened milk can be cumbersome to strain, in which case simply pluck them out with clean hands!) Then, transfer the grains to a fresh cup of milk and allow to ferment again. Store your fermented milk kefir in the refrigerator with a loose lid. Enjoy within 1-2 weeks.