After tea leaves are picked and dried in spring, they are stored in tightly sealed stoneware jars to protect the tea from the heat and humidity of summer. The high neck of such storage jars was designed to accommodate a stopper, which would have been lashed to the vessel with a cord threaded through the four lugs. During special tea gatherings during the autumn called "kuchikiri chaji", the paper lid is cut away from the jar and the tea is ground into a fine powder using small stone mills set up in the preparation areas (mizuya) adjoining the tearoom.