Ensuring your product has a stable shelf life, maintains freshness, and tastes how your customers expect it to all start with the filling process. Both hot fill and retort filling processes involve heat treatment to enable the packaged product to be sterile and shelf-stable without refrigeration. These filling processes are used to preserve foods such as salsa, soups, condiments, beverages and more.
How Hot Fill and Retort Works
The first thing to consider in this process is the pH level of the product being packaged. This will determine the heating treatment that will be used. Whether you are utilizing hot fill or retort for a filling process, both can be used for glass bottles and jars with a metal lid as a closure. The closure with glass packaging is sealed with a plastisol liner for both hot fill and retort. However, the retort process requires a more specific high-heat liner. While both processes involve a heat treatment, they are different in when and how the heat is applied.
Hot Fill
Hot fill is when heated, sterile products are filled in non-sterile packaging. Generally, foods with a lower pH level (4.5 and below) will utilize a hot fill process for packaging. With this process, the product has already gone through a sterilization process based on a predetermined time and temperature prior to the filling step in the process.
The pasteurization treatment, which must be approved by the processing authority, is done at temperatures of 85-100°C (185-212°F.) The products are filled at temperatures determined by the processing authority’s minimum mandate. The cap is then secured immediately, keeping the product inside the bottle or jar sterile and shelf-stable.
Retort
The retort process is different from hot fill because with this process non-sterile products are filled in a hermetically sealed, non-sterile package. Foods with a pH level greater than or equal to 4.5 go through the retort process, which involves temperatures greater than 100°C (212°F).
The retort process starts when the product is mixed and then filled into bottles or jars at room temperature. Once the product has been filled, the package is loaded into a retort pressure chamber. While in the chamber, the package’s contents are sterilized with pressurized steam. This does require the product to be exposed to high temperatures for much longer than the hot fill process.
How Can MJS Packaging Help?
The filling process used for a product can affect its shelf life and quality. It is important that your product has the packaging it requires no matter your fill process. MJS Packaging can assist you with glass jar and bottle packaging that will meet your needs for any type of filling process, whether it is hot fill or retort. We have a strong understanding of all the things that need to be considered when packaging your product.
Contact MJS Packaging today or talk with one of our knowledgeable packaging solutions specialists by calling (800) 915-2262.
