[abakker]

Question on food safety: What is the longest available cook time? I ask because in an aerobic environment an extended cook time is necessary at 135 degrees to achieve pasteurization. Even in sous vide, it is necessary to extend cook times to achieve sufficient pasteurization. With oxygen present I expect you could grow some very interesting cultures. Specifically in foods like ground beef, where there is no inhibiting the movement of bacteria from surface to center of the cut.

[lifekaizen]

We've focused on your daily gourmet of 30 minutes or less, and we make sure to cook to safe temperature. Above 131F is considered outside of the bacterial growth zone (basically between fridge to 131F, bacteria multiplies like crazy); if you hold it, it will eventually pasteurize. A more insurmountable problem comes from anaerobic bacteria that can exist in a true vacuum, and the spores will survive high temperatures; we avoided that problem by not requiring a vacuum.

[dragonwriter]

> Above 131F is considered outside of the bacterial growth zone (basically between fridge to 131F, bacteria multiplies like crazy); if you hold it, it will eventually pasteurize.

Most food safety sources I've seen cite 40-140 degrees Fahrenheit (or 5-60 degrees Celsius) as the "Danger Zone" in which foods should not be held.

[crygin]

It's a combination of temp & time -- 131F for four hours will pasteurize (and, conveniently, is below the coagulation temperature for both the white & yolk of eggs, so you can home-pasteurize eggs for mayo/etc with a water bath). Contrariwise, 140F wouldn't be safe if it only reached it for a few seconds.

[abakker]

yeah, the difference being the time...hence my original question. At 135 degrees you need at least 35 minutes of hold time once you have reached the target temperature.

http://sousvide.wikia.com/wiki/Importance_of_temperature_con...

[lifekaizen]

correct. that's why it's beautiful to control the entire process with software -- we know your time/temp curve. And why the USDA still gives one temperature which assumes an instantaneous point of contact, but higher than you need if you can simply hold the temp. (As a heuristic, staying lower gives you better quality food.)