Here are some ways to remove milk kefir grains from finished kefir. If your kefir is thick, it will help to shake it up or stir it up first, to break up any curds and make the grains easier to locate.
Use a plastic mesh strainer. Since milk kefir (a.k.a. dairy kefir) tends to be a bit thick, you may need to use your fingers or a plastic spoon (in a swirling motion) to help work the kefir through the strainer, but this method will leave you with a uniform consistency for the kefir as well as safely securing the kefir grains in the strainer so they can be added to fresh milk. Check out the this plastic mesh strainer available on our website. Stainless steel can be used if necessary; just be sure it's stainless steel and not a reactive metal.
Use a nylon mesh bag to secure the milk kefir grains. You can make one with a small square of undyed nylon mesh that you can get at a fabric store. Make sure it is a very fine-mesh fabric so the grains don't escape. Place the grains on the mesh, then tie up the corners with some unwaxed, unflavored dental floss. Make sure the bag is secured at the top so the kefir grains don’t escape, and make sure the bag is roomy enough to allow for some growth from the grains. Place the bag containing the grains in the milk and allow to culture as normal.
Use your fingers. As your milk kefir grains grow in size, you can often use your hand to remove the kefir grains quickly. Make sure your hands are very clean though or you risk contaminating your kefir and the kefir grains.
Pour the kefir out into a shallow bowl. This will make the grains easier to see, and when you have removed them, you can pour the kefir into a container for storage.