Originally Posted by
Kagehitokiri
i see mentions of medium rare, what about rare? ive never understood FDA cooking temperature of 145 / medium well. i assume raw meat/seafood/eggs mostly involve where it comes from and how it is handled.
This has to do with a particular phenomena in heat/cellular biology, which involves the Arrhenius equation. Simply stated, cellular death is a function of TIME and TEMPERATURE. A few examples:
Take a 1000 DegF iron rod, touch it firmly for just 0.001sec...you will get burned.
Take a 212F (water boiling) plate, touch it for 0.5 sec- probably OK
Take a 130F Sous Vide bath, plop you hand in it for 30 seconds, fine.
HOWEVER, on this latter point- leave that meat for 3 HOURS and every bacterial cell in the meat will be dead. It is pasteurized.
It isnt JUST the temperature, it is how long the cell is exposed to that temperature.
THIS is the magic, IMO, of sous vide. Chicken, pork, Hamburger- all meats that have some risk of pathogens, can be pasteurized and made safe for consumption, but at a temperature that will yield a much different taste experience.
The FDA recommendation of 145 is predicated on 'it will only be at 145 for a few minutes, maybe 10 minutes, between measuring the temp and consuming'. But if you can get it to 130 for 3 hours (or 128, where I put rare) you will have the same level of safety.
(Ive spent a good many years working in tissue heating as a component of medical device development....this science is critical in calculating thermal dosimetery for creating heating zones to kill tumors and such. Also for understanding heat based sterilization of medical products.)