Vacuum is not required. Like I said you just want to remove the air or gas. You do not need a vacuum for this. There are other techniques. Do you own a chamber vacuum sealer with gas flush?
You don't need a hermetic seal. You probably know this from poaching in oil. You can cook things in plastic wrap. It's a fact. Read up thread. Do I use a sealer? yes.
A temp fluctuation of one degree is not going to dramatically effect a 48 hour cook time. I appreciate the science aspect of SV and I do like things to be precise, but there is a little fuzzy factor in practice. It's good to be precise in a book. Its gives a base on which to be creative or deviate from for the Art in Culinary Arts.
OK, allow me to retort...
Vacuum is not required in SV cooking. And, ice is not required for ice skating. :-)
My dear pounce, saying something over and over doesn't make it right, no matter how many times you've repeated it.
Would you please explain to us WHY
vacuum in SV doesn't matter? And, what other gas besides oxygen are you trying to remove from your cooking bag?
Again, vacuum (the "vide") in Sous-vide is essential. You need to remove oxygen to prevent food from spoiling, changing color and more than anything - preserving taste. Some cooks are able to fill their bags with non-reactive gas, but that goes well beyond home and restaurant cooking, and remains the prerogative of industrial production.
As far as sealing/cooking in plastic wrap: if you don't have a seal, and soak meat in warm water for hours at a time - you will have achieved a successful bacterial multiplication. Enjoy your adventure in food poisoning! If you are cooking fish, yes - the time/bacterial load are not large enough to develop, but shellfish may be a different story, and meat will spoil in just a few hours. You use a sealer yourself, so why are you trying to argue the seal issue?
FYI, I don't own a vacuum chamber - the least expensive unit I saw was $1900 - well beyond of what I am willing to spend right now, but I will invest in one of those some day, mostly for cured meat/sausage making, as well as SV.
Temperature issue comes down to what kind of consistency you are trying to achieve: it may be more important in a restaurant set-up, than at home.
We are all here to learn form each other, and any information is important, and any opinion is welcome. It's not about who is better, but how to do the best we can. That having been said, one needs a proper wok and sufficient heat to stir fry, exact measurements for baking, and the right equipment to SV. Don't you agree?
I don't want to end up in the proverbial land where any poaching is called "sous-vide", but rather aim to preserve and develop the art of that approach to cooking. Some may disagree... Well, those same people would most likely mix powdered wasabi with soy sauce and pour it over overcooked fish and call it a great sushi experience. I just hope it's not you.
Edited by MikeTMD, 25 January 2008 - 01:01 PM.