Filter discs allow for gas exchange while providing 99.97% efficiency filtration down to 0.3 microns. Autoclavable, and 100% reusable. Fits a wide mouth mason jar.
Fill mason jar with grain or other substrate. Drill 4 small holes or one quarter inch hole into metal mason jar lid. Fit the filter patch inside the ring, followed by the metal jar lid, place on jar and screw ring on. Pressure cook contents of jar to sterilize substrate then inoculate in front of flow hood or in still air box.