The pasteurization tunnel (1) comprises two decks (2, 3) that are arranged on one another. A conveyor transfers beverage packs (4). A set of spraying pipes (5, 6) provided with nozzles (7) for spraying the beverage packs, where the spraying pipes extend transversely to a conveying direction of the conveyors. The spraying pipes of the first deck is connected in series with the spraying pipes of the second deck to guide a spraying liquid through the first deck to the second deck, where the conduit cross-section of the spraying pipes is larger in the first deck than in the second deck. The pasteurization tunnel (1) comprises two decks (2, 3) that are arranged on one another. A conveyor transfers beverage packs (4). A set of spraying pipes (5, 6) provided with nozzles (7) for spraying the beverage packs, where the spraying pipes extend transversely to a conveying direction of the conveyors. The spraying pipes of the first deck are connected in series with the spraying pipes of the second deck to guide a spraying liquid through the first deck to the second deck. The conduit cross-section of the spraying pipes connected in series is larger in the first deck than in the second deck, where the several series connections are provided along the conveying direction. The second deck is situated above the first deck, where the number of nozzles per spraying pipe is higher in the respective upper deck than in the respective lower deck. One of the number of nozzles per spraying pipe provided in the first deck differs from the number of nozzles per spraying pipe provided in the second deck, or distances between the nozzles of the first and the second decks differ from each other to compensate a geodetic pressure differential between the first and the second decks. An inspection port is provided in a region of the second deck for visual spray inspection. The spraying pipes of the second deck comprise an access opening that is accessible from outside. A third deck is situated between
