Polymer BEAN CELLARS® are designed to be used by both professional and home baristas as part of a single dosing grinder workflow or as individual retail portions for cafe customers. Each BPA-free, hard-wearing polypropylene Bean Cellar is capped with our proprietary one-way valve system that allows the CO2 of freshly roasted coffee to outgas, displacing the lighter oxygen out of the valve at the top of the cap. For purchase in bulk go here.