# Effects of more/less vacuum on meat



## SmokinEdge (Feb 21, 2021)

https://www.engineersedge.com/h2o_boil_pressure.htm

Here is a link to a table of the boiling point of water at different amount of vacuum.
I generally SV between 131-140* for longer times, but for those who cook above 145* with a full vacuum this might be interesting.

I looked up a couple videos of people testing the vacuum on their vac sealers. These were the common Food Saver types. In the tests I saw, they were able to pull between 18 and 22 inches of vacuum. A Vacmaster might be able to pull slightly more, I don’t know. Anyway, according to the chart in the link water will start to boil around 145* with 22 inches of vacuum. The higher the temp the more likely this is happening.

I read a food science study where they tested chicken and fish at different rates of vacuum. They were using a chamber style machine common in commercial kitchens. They vacuumed chicken and fish at 90%, 95% and 99% plus 15 seconds Vacuum. I’m guessing on the high side they had 28-29 inches of vacuum much more than you could produce at home. They cook these different pieces at the same temp and time in SV bath. The results were with the 99% vacuum the meat was watery, but dry to the mouth and mushy. The 90% vacuum was described as perfectly cooked And was preferred by all in the test. Beef was also tested the same way, and while no significant texture difference was noted, they all preferred the 90% vacuum.

Im wondering if varying the amount of vacuum from cook to cook can change the finish product given time and temp stay the same? Since it’s hard to know how much vacuum is applied from seal to next I just don’t know. What say you?

For the most part I use ziploc type bags and use the submersion method to expel the air.


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## SmokinEdge (Feb 21, 2021)

Here is a link to the study.

http://www.cookingissues.com/index.html?p=1042.html


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## Wurstmeister (Feb 21, 2021)

Thanks for sharing. Looking forward to seeing how the membership replies.    Before my SV became recycled by the Jawas, (wires out, head dangling, lights flashing, grinding sounds)  I would vac seal my bags, go low temp like you & longer time.


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## daveomak (Feb 21, 2021)

I don't apply vacuum to any meat when curing or SV'ing...   I tried curing a couple of loins while stretch netted and relaxed in a bag... The compressed meat, netted, came out tough...  relaxed, not tough...  
When I vac pack meats for the freezer, I now freeze the meat, relaxed, on a sheet pan and then vac pack...   I'm thinking you will be squeezing all the juices out and making a dry product...  Same with curing etc....
I freeze veggies before vac packing to freeze also..  like asperagus...  
Some vac machines probably won't cause that problem...  like food saver... not enough vacuum...   but hey, why not try no vac SV and curing...


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## sawhorseray (Feb 21, 2021)

Thanks Dave , I just learned two valuable points from your post! #1, freezing meat relaxed will keep the juices from being sucked out, I'll be doing that forever on. #2, I had no idea you could freeze and vac-seal asparagus. We love the stuff but only buy when it's on sale. Does the frozen asparagu stay in pretty good shape and have good flavor after being  vac-sealed? Thanks again Dave. RAY


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## robrpb (Feb 21, 2021)

daveomak said:


> I don't apply vacuum to any meat when curing or SV'ing...   I tried curing a couple of loins while stretch netted and relaxed in a bag... The compressed meat, netted, came out tough...  relaxed, not tough...
> When I vac pack meats for the freezer, I now freeze the meat, relaxed, on a sheet pan and then vac pack...   I'm thinking you will be squeezing all the juices out and making a dry product...  Same with curing etc....
> I freeze veggies before vac packing to freeze also..  like asperagus...
> Some vac machines probably won't cause that problem...  like food saver... not enough vacuum...   but hey, why not try no vac SV and curing...



I wish I read this earlier this morning. Earleir I vac sealed two pork loins. I just checked and it was too late to take them out of the vac bag. In the future I too, will be freezing before vac sealing. Thanks.


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## thirdeye (Feb 21, 2021)

daveomak said:


> I don't apply vacuum to any meat when curing or SV'ing...   I tried curing a couple of loins while stretch netted and relaxed in a bag... The compressed meat, netted, came out tough...  relaxed, not tough...
> When I vac pack meats for the freezer, I now freeze the meat, relaxed, on a sheet pan and then vac pack...   I'm thinking you will be squeezing all the juices out and making a dry product...  Same with curing etc....
> I freeze veggies before vac packing to freeze also..  like asperagus...
> Some vac machines probably won't cause that problem...  like food saver... not enough vacuum...   but hey, why not try no vac SV and curing...


I do the same. Even go so far as to freeze soup or chili in Tupperware, then pop out of the container and vac seal.


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## daveomak (Feb 21, 2021)

sawhorseray said:


> Thanks Dave , I just learned two valuable points from your post! #1, freezing meat relaxed will keep the juices from being sucked out, I'll be doing that forever on. #2, I had no idea you could freeze and vac-seal asparagus. We love the stuff but only buy when it's on sale. Does the frozen asparagus stay in pretty good shape and have good flavor after being  vac-sealed? Thanks again Dave. RAY



It tastes better than not having any.... Hard to beat fresh...
The BEST asparagus I ever had was, from behind a friend's house...  On the side of a hill in a rock infested side hill....  It was awesome..  I think it had to do with the minerals from the rocks...   The ground was about 100 ft above the Okanogan river on a western facing slope..  A spring seeped water, where it was growing...  Don't know what kind of soil or if it was rocks, gravel and sand....  but it was a WOW moment....
A local club imports stuff like asparagus, raspberries and blueberries to sell to the public...  Put in an order and they get it from somewhere...  I think it's the Lions club maybe...   They may go to the processor and purchase 5-10,000#'s and meet at a parking lot to distribute the stuff...  The lineup is about 10-40 folks deep for all day... takes about  5 minutes to get your order and you are done...


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## TNJAKE (Feb 21, 2021)

We vac seal asparagus and brussel sprouts and we've found that if you thaw while still in vac pack it gets kinda soft so we started taking them out and thawing on paper towels. Gives us a much better end product that way


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## SmokinEdge (Feb 21, 2021)

Ok, I’m going to go ahead and SV some chicken thighs.
2 under full vacuum and 2 ziploc bagged will air out. I’ll let them run 3 hours at 160*,  unless someone has a better idea. Thanks.


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## jcam222 (Feb 21, 2021)

I’ve done chicken thighs sous vide a couple times in the last two weeks. Both times I did them confit style a rounded in fat. One time duck fat and one time olive oil. When I used the sealer for that I use moist setting which I think doesn’t impart as much vacuum. Cooked at 165F once for 6 hours and once 3. Both were tender and juicy but the 3 hour was best.


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## thirdeye (Feb 21, 2021)

SmokinEdge said:


> Ok, I’m going to go ahead and SV some chicken thighs.
> 2 under full vacuum and 2 ziploc bagged will air out. I’ll let them run 3 hours at 160*,  unless someone has a better idea. Thanks.


I'm with 

 jcam222
 and prefer SV of 165° on thighs.  When I smoke or grill them I often to a butter broth step and take the internal into the 190°'s.... so SV @ 165° for 4 hours is my sweet spot. I prefer zipper bags so I can remove, open the bag and probe for tenderness.  

 Here is a good article from the food lab on thighs.








						Crispy Sous Vide Chicken Thighs With Mustard-Wine Pan Sauce Recipe
					

Sous vide techniques yield chicken with unparalleled levels of juiciness. Finish your chicken on the stovetop to crisp it up.




					www.seriouseats.com


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## smokeymose (Feb 21, 2021)

SmokinEdge said:


> Ok, I’m going to go ahead and SV some chicken thighs.
> 2 under full vacuum and 2 ziploc bagged will air out. I’ll let them run 3 hours at 160*,  unless someone has a better idea. Thanks.


Curious to see how that goes. I haven't been impressed with SV chicken.....


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## jcam222 (Feb 21, 2021)

smokeymose said:


> Curious to see how that goes. I haven't been impressed with SV chicken.....


I wasn’t a fan of breast but man the thighs are killer. Try them confit style in the vacuum pack and crisp in 500F oven after. Juicy


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## Gateman (Feb 21, 2021)

thirdeye said:


> I'm with
> 
> jcam222
> and prefer SV of 165° on thighs.  When I smoke or grill them I often to a butter broth step and take the internal into the 190°'s.... so SV @ 165° for 4 hours is my sweet spot. I prefer zipper bags so I can remove, open the bag and probe for tenderness.
> ...


You don’t have any problem with the bags leaking? I’ve had vac bags seal fail twice now. 
think there not best choice for SV, I don’t know why they won’t stay sealed.


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## daveomak (Feb 21, 2021)

Gateman said:


> You don’t have any problem with the bags leaking? I’ve had vac bags seal fail twice now.
> think there not best choice for SV, I don’t know why they won’t stay sealed.




Not enough heat or time when sealing..  Maybe the bag is wet....   What machine you using...


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## Winterrider (Feb 21, 2021)

Gateman said:


> You don’t have any problem with the bags leaking? I’ve had vac bags seal fail twice now.
> think there not best choice for SV, I don’t know why they won’t stay sealed.


Are you sure you don't have moisture getting sucked up into the Vac before seal Is complete ? I have never had a seal yet ( knock on wood ) go bad while SV'ing.


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## jcam222 (Feb 21, 2021)

Gateman said:


> You don’t have any problem with the bags leaking? I’ve had vac bags seal fail twice now.
> think there not best choice for SV, I don’t know why they won’t stay sealed.


 I use a darn near 15 year old food saver and have no issues with seals leaking. I use cheap bags off Amazon. Sometimes if I’m using a bigger bag to get things situated and sealed I will fold it and slide in a smaller bag for a second seal. I’ve never leaked though eith or without doing that.


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## thirdeye (Feb 22, 2021)

Gateman said:


> You don’t have any problem with the bags leaking? I’ve had vac bags seal fail twice now.
> think there not best choice for SV, I don’t know why they won’t stay sealed.


I've never had a zipper bag leak. I do buy the "freezer bags" which are a different plastic, and have a double groove on the closure. And at least90% of the time the zipper end is out of the water and clipped to the edge of my container. I do use vac bags on frenched  lamb racks because of the bones, never had a leaker there either.


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## daveomak (Feb 22, 2021)

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....








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


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## PolishDeli (Feb 22, 2021)

SmokinEdge said:


> 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?


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## zwiller (Feb 22, 2021)

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.


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## Gateman (Feb 22, 2021)

daveomak said:


> 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
> 
> ...


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.


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## TNJAKE (Feb 22, 2021)

Gateman said:


> 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?


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## Gateman (Feb 22, 2021)

TNJAKE said:


> 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


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## SmokinEdge (Feb 22, 2021)

PolishDeli said:


> 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?
> 
> ...


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.


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## PolishDeli (Feb 23, 2021)

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.


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