Method of heating a package

Abstract

The present invention relates to a method of heating a package, comprising the steps of: placing a number of packages in a retort, pressurising the retort to a first pressure by the supply of a gaseous pressurisation medium of low moisture content, supplying a heating medium for heating the package and the product packed in the package, raising, in connection with the supply of the heating medium, the pressure in the retort to a second pressure, and, during the final phase of the heat-treatment, reducing the pressure in the retort in such a manner that the pressure of the product packed in the package is higher than or equal to the pressure prevailing in the retort outside the package.

Dependencies are inferred from the claim text.