Hot fill is a packaging process in which pasteurised liquid or semi-liquid food is filled into containers at elevated temperature so that the product itself sterilises the container interior before sealing and cooling.
In trade practice
Hot fill is commonly used for acidic products such as fruit purees, juices and concentrates, where the low pH supports microbial control alongside heat. The filled and sealed container is typically inverted or held for a defined dwell time to ensure the closure and headspace are exposed to the hot product. QA teams must validate fill temperature, dwell time and cooling rate as critical control points. A common failure mode is filling below the minimum temperature, which can leave the closure inadequately treated and compromise shelf life.
In a specification
A hot-fill product specification should state the minimum fill temperature, target pH, required dwell time and the shelf-life claim under ambient storage conditions that the process is validated to support.