I just got a sous vide machine and so far love the results. But right now I am using a recipe for short ribs that call for a 48-hour cook time at 131°F. According to food safety sources, that temperature is in the “danger zone.” How can it be safe to hold beef at 131° for 48 hours?
It comes down to time; traditional safety guidelines assume just a minute or two at the target temperature, which then has to be quite high in order to be safe. But you can achieve the same level of safety at a lower temperature for a longer time.
This guide talks about the science behind it. The pasteurization charts in particular are useful; they show how long you have to keep each type of protein at what temperature to safely pasteurize it.
I may be wrong, but I believe I’ve read that one of the keys to pasteurization is that the entire product is at the same temp throughout. The bad stuff doesn’t have anywhere to hide and grow.
Just remembered, here’s a thread from last year about sous-vide: https://boards.straightdope.com/sdmb/showthread.php?t=885642&highlight=sous+vide
Should probably ask a mod to move this to Cafe Society.
This detailed article from Food Safety Magazine asks and claims to answer that same question:
Apparently the upper end of the official danger zone isn’t all that dangerous:
I believe Clostridium perfringens will grow on the hotter end. But not at the OP’s temperature.
Here’s an analogy:
You could run through a room that was 150 degrees & humid. This is about the same as climbing into a hot car. The brief exposure isn’t pleasant but also isn’t fatal. However, if that temperature was maintained and you had to sit there, you’d soon be dead. This is sous vide cooking temps for people. Not hot enough to kill instantly but plenty hot enough over time.
Similarly, scalding of skin occurs at different temps and times. From wikipedia, scalding:
No idea, but excellent thread name / poster combo!
Moderator Action
Moving thread from GQ to Cafe Society.