I've been looking into Sous Vide (under vacuum) cooking... It all started when I was watching a show about cooking eggs and how the whites set at ~ 60°C but the yolks set at ~65°C, with the perfect egg (for those like me that like a runny yolk) being cooked somewhere in between those temperatures.
After lots more reading, it is and isn't as simple as that... From a temperature perspective, it is - cook it at 63°C and you'll set the white and keep a runny yolk, but how long do you cook it for? That is the important question, but not necessarily for the reason you ask! Obviously you want it to be long enough for the white to set, but there is another factor to consider - food safety!
Cooking food not only changes the appearance and taste of food, but it also has a MAJOR impact on food safety! Why don't you each raw meat, chicken, eggs, fish, etc? Because it just isn't done?
Let's take Sushi as a prime example. Sushi is raw fish and that's okay isn't it? NO! While Sushi is often considered to be okay, that is only because it is selected and handled in a manner that minimizes (not eliminates) any risk of food borne bacteria that may actually exist! Just check the web for cases of "bad sushi" and you'll see plenty of tales of bad experiences!
This isn't totally the fault of the ingredients, it is just that bacteria has gotten added somewhere along the line and that is the one part of the cooking process that is often overlooked! Food Safety! Cooking food at a particular temperature for a set time period kills the bacteria that cause most of the bad experiences! For example, cooking eggs at 62°C for 30 minutes may change their appearance, but it may not kill all the bacteria. However, cooking eggs at 62°C for 1 hour and 15 minutes is shown to reduce the potential number of bacteria by over ONE MILLION! Obviously nothing in life is certain, but I'd rather take a 1 in Million chance of getting sick against a 1 in one hundred chance!
What? Does that mean that eating Sous Vide means I may get sick? Not necessarily - As with anything in life, it is just a question of risk - Knowing what the risks are and doing everything possible to minimize them! Cook a perfect pork chop and put it back on the plate that it came from and you may just collect the bacteria you started with, such that you are effectively eating the raw pork! As with any cooking, it isn't just the cooking, but the entire process that comes into focus!
I want the perfect egg - look out "Sous Vide", here I come!
