Effects of more/less vacuum on meat

[PolishDeli]

Here is a link to a table of the boiling point of water at different amount of vacuum.

If the pressure inside a foodsaver bag is 20 inHg, the water inside the bag should all turn into steam at about 160°F.

At that point, shouldn't the bag look like a baloon?

It doesn't.

Why not?

 

[zwiller]

While I think there is merit to this I still feel that many are overlooking the needs to brine when SVing. I think the logic is the vacuum sealing drives the salt into the meat but that is bogus. I just ran a loin where I dry brined for a week prior to SV. I also used STPP but simply applied it instead on injecting and to my chagrin, it appears to have worked well (not much juice in bag). I also ran said loin 24hrs instead of ther typical 4-8hrs most do. Results to follow when I eat it. I will say I am becoming kind of picky and hate the distortion and flattening that vac sealing does. Pork chops that are nearly 2" thick end up being half the size.

 

[Gateman]

I found this picture... Zip lock Freezer Bag.... Top is open and folded over the container lip... Held in place with one of those binder clips... Then the lid is installed to prevent evaporation....

View attachment 486184

Looking close, you can see the binder clips "shadow" in the lid.....

View attachment 486185

I see, the problem is the seal is turning loose.
it opens up like it’s not melting and sealing very good.
it’s a new food saver sealer and food saver bags, I thought they did a better job.

 

[TNJAKE]

I see, the problem is the seal is turning loose.
it opens up like it’s not melting and sealing very good.
it’s a new food saver sealer and food saver bags, I thought they did a better job.

My food saver is a workhorse. Sounds like the heat strip needs to be replaced. Anyway it's new enough to just exchange it?

 

[Gateman]

My food saver is a workhorse. Sounds like the heat strip needs to be replaced. Anyway it's new enough to just exchange it?

Should be got it at Christmas

 

[SmokinEdge]

If the pressure inside a foodsaver bag is 20 inHg, the water inside the bag should all turn into steam at about 160°F.

At that point, shouldn't the bag look like a baloon?

It doesn't.

Why not?

That would be the theory.
Science is what it is. No going around it,,,, so I did do a test with chicken thighs. Some at full vacuum from my Food Saver, and some in ziploc bags submerged to evacuate air. Temp was 160* for 3 hours. My son just liked the vacuum bag chicken taste better, but could not explain why. I thought both were identical. Juicy, good texture and tasty almost identical.

So this leads me to believe that the actual vacuum inside the bag, around the meat, is no where near 20 hg. That might be what the machine pulls, but the collapsed plastic bag does not allow that amount of vacuum to pull at the meat.

 

[PolishDeli]

Correct. If a pressure gauge goes down to 20inHg from 30inHg (1atm), the bag and its content are being crushed by the atmosphere with a pressure of 10inHg.
So the more appropriate analogy would be to compare food that has been beaten with meat mellet.

To achieve actual low pressure cooking, the food needs to be in a container that can support the weight of the atmosphere. e.g. a mason jar.