Steril-packed agar plates are unwrapped and prepared for filling. Mix the medium thoroughly just before making the agar plates. Then pour the agar plates. Half full agar plates contain approximately 30 milliliters of medium. When the plates are stacked, the agar slowly cools and the formation of condensation water is reduced. Color codes are used to identify the agar plates. Then the solidified plates upside down to avoid condensation water on the agar surface. Plates may be wrapped in the sterile plastic bags for longer storage.