Kefir Fermenter: Set for Use with Jar (Wide Mouth) You Already Have Set for Use with Jar You Have. Consists of Lid (For Wide Mouth Mason Jar) + Big Container for Kefir Grains + Straw with Cap Place kefir grains in container and install in jar. Save money: don't buy jar if you have one. The same as other Microbiota, Inc. Kefir Fermenters but without Mason jar. Type KEFIR FERMENTER to see other devices related to home kefir with or with out kefir grains