Method for production of aseptically filled spouted pouches (1) having an interference fit plug (50) and a cap (70). The interference fit plug is releasably mounted over the top end of the neck of the spout body and hermetically seals the product passage of the spout body. The plug is adapted to be removed by an aseptic filling machine (302) and to be replaced by pressing the plug onto the neck after filling of the pouch. The plug removal, filling, and replacing of the plug are preferably performed in an aseptic environment. The cap is after the filling of the pouch and the replacing of the plug onto the neck. The capping is preferably performed by a capping machine in a non-aseptic environment (308).