Kefir Fermenter: Simple Set for Homemade Kefir with Fresh Kefir Grains Set of container with kefir grains and plastic lid with mesh 0.7mm. Dramatically simplify the process of homemade kefir making: no more strainer, spatula, pouring from one jar to another, washing. Just pour milk and drink fresh kefir next day. You buy it once but use hundreds times with the same kefir grains. High quality Kefir Grains in container are dried. They start working from the first batch. Dry kefir grains survive long trip, overheating and cold. BUY THE SAME WITH FRESH KEFIR GRAINS FOR $14.95: TYPE B01MCWGB5D in Amazon.com browser Container for grains and lid are FDA approved. BPA free. Mesh in the lid has holes 0.7 mm. It allows excellent access of air but protects from even small flies. Use any glass mason jar. Recommended volumes from 10 oz to 50 oz (0.3 L - 1.5 L).