Kefir

To make milk kefir, use the best quality milk you have available. Combine your kefir grains with milk in a 1: 7 ratio (i.e., ½ cup of grains will culture one quart of milk, and so on) in your jar. Secure the lid to prevent insects from checking your kefir out (they love kefir, too!). Set your jar on the counter and wait, every now and then giving the jar a gentle shake to stir things up. The culturing should take 12 to 24 hours at room temperature. The milk protein will coagulate and separate from the whey; at this stage the kefir is ready. Strain out the kefir grains.
If you wish a tarter flavor and higher folic acid content, leave the freshly strained kefir out to culture further while you start another batch with your grains, beginning the process again with fresh milk. Kefir grains can be covered with milk and stored in the refrigerator for up to a week; they will continue to culture, but at a much slower rate.
Read the entire article on Kefir here.
Photo credit: Lisa Reagan