- A critical defect.
The package bulges due to gas formation from bacterial contamination, or excess internal residual air.
- The food was underprocessed or contaminated during aseptic processing.
- The package material was not properly sterilized or was contaminated during aseptic processing.
- The package was overfilled or a proper vacuum was not drawn, which resulted in an improper thermal process.
- The food package was under-processed during thermal processing.
- There was insufficient chlorine in the cooling water.
- The package leaked after processing.
- The post-process handling was too rough.