What is the downside of sous vide?

Although cooking food in vacuum packaging reduces post-processing contamination, pathogens present in the raw materials are still a concern. Without a validated kill step, outgrowth of typical pathogens is still possible in vacuum packaging. Pathogens of concern such as Salmonella spp., pathogenic E. coli, and Listeria monocytogenes are all facultative anaerobes and can survive in an aerobic, oxygen rich, environments as well as reduced-oxygen and anaerobic environments such as in vacuum packaging. In reduced oxygen or oxygen free environments like vacuum packaging, anaerobic spore forming bacteria become a significant concern for sous vide processing. Bacterial spores from these organisms are only killed under extremely harsh thermal processing conditions compared to actively dividing vegetative bacterial cells. Toxin production occurs while in the anaerobic environment provided by sous vide packaging, which can then cause severe illness if strict temperature control is not maintained.