This example of a white paper from the Retort.Com website discusses the 4 types of retort processes, namely
. Saturated Steam – direct steam heating
. Water Immersion (Rotary and Static) – indirect steam heating
. Water Spray (Rotary and Static) – indirect steam heating
. Steam-Air (Rotary and Static) – direct steam heating
Each process is described in a few simple paragraphs and illustrated with a photograph. The pros and cons are then fully contrasted in a table for each process.
Maybe more useful than this paper is the other 13 white papers on many aspects of retorting on the site.
An in container sterilisation process has the real advantage that packaging takes place before sterilisation, negating any problems in packaging. A major disadvantage are the long cycle times and high heat inputs required which result in harsh product treatments.
The Shaka Process (not related to the Zulu King) offered by Packaging Technologies and Inspection
overcomes this by agitating the containers during sterilisation, thereby reducing heat transfer times for liquid and semi liquid products.
Images from Packaging Technologies and Inspection
The massively reduced cycle times reduce product damage and batch turn around times. Although the equipment is more costly for a given batch size the faster turn around time increases the hourly capacity and reduces the cost.
This is rather high tech equipment but the principles should be borne in kind and could be borne in mind and might initiate some interesting process and equipment ideas.