We recommend batching at (2) gallons or as close to 256 ounces as possible. Over filling of the keg will result in the beverage back-flowing into the regulator causing the dispenser not to work. If this happens, turn the regulator to the off positions, release all pressure in the keg by pulling up the pressure relief valve on the lid, removing the lid, and emptying out enough liquid so the gas dip tube is no longer submersed.