Quote: (05-04-2014 12:54 PM)deerhunter Wrote:
Thanks Dude 3737, great tip on not lowering the pressure too much in your chamber vacuum sealer. Can't believe I never thought about that before. I seal hundreds of pounds of red salmon as well other stuff every year (a lot of hunting and fishing), and always just turn the vacuum suction to maximum. More is better theory. Definitely see the water boiling in there. I will have to play with it to find the sweet point now. I don't cook sous vide, but I am sure it still affects the quality of my final product.
Damn I never expected anyone to have any experience with chamber vacuum sealing or have any clue what I was talking about haha, but there you go, just goes to show the diversity of dudes that are on the forum.
Every chamber sealer is different so you'd have to check out the manual, but you want to adjust the vacuum pressure accordingly.
Since water boiling is relative to air pressure and temperature, it helps if you chill the food thoroughly before vacuum sealing. That's tip 1.
Tip 2 is understanding at what pressure water will boil out of food. With chilled food right out of the fridge, water begins evaporating rapidly at pressures less than 20 mbar / 0.3 psi, and it boils at 5-10 mbar / 0.1-0.2 psi. Some chamber sealers have a digital display of the chamber pressure. Stop the vacuum well before the pressure reaches these low levels. Nearly all foods are well-sealed and preserved at a pressure of 30-50 mbar / 0.4-0.7 psi. Pulling a harder vacuum to get a tighter seal won't preserve the food any better and at that point is only damaging the texture of the fish or whatever else you're sealing.
For anyone in the room wondering what the hell we're talking about, it's this:
As you can see in the video ^^^ the first machine has a display of vacuum percentage. This knucklehead is letting it go to 99.99% which is way too high and if you actually cooked that salmon it would have a shitty, mushy texture once cooked sous vide. He should have set the machine to a 90% vacuum.