What Are You Cooking Sous Vide Today? (Part 3)

[rotuts]

@KennethT

 

That's an excellent question.

 

it would be interesting to see if this has been looked at 

 

'not a difficult experiment to do :

 

get a supermarket roast .  SV for 3 - 4 hours,   under aseptic technique 

 

get a center sample , and future.   back in th day that would have been easy for me to do.

 

theoretically , on a roast properlly handled , the center of the met would not have bacterial contamination.

 

the exterior and manipulated surfaces for sure.

 

Obliquely , it been mentioned by reliable SV sources that it would be inappropriat

 

to SV jaccarded meat  , ie Costco routine meat , one would ask for non-jaccardedd

 

which Costco , at least back in the day would sup[ply on request 

 

there is a thread on this.

 

of course , the bacteriology might not have been actually studied.

[gfweb]

A bunch of NY strips for guests.  SV lets me forget about the cooking and be a better host. 😀

[Bernie]

10 hours ago, KennethT said:

Is anyone else concerned about bacterial buildup in the center of the roast while cooking for that amount of time?  When you have a large roast, it would probably take more than 4 hours for the center to get out of the danger zone.  It would spend a long time in the "bacterial multiplying like crazy zone" - around body temperature.  I'd be curious about everyone's thoughts about this - I haven't done much SV for quite a while but I do remember this being a concern.

Well, hopefully if the roast was originally butchered and handled correctly, there should be minimal bacteria inside the roast. The only way for it to get inside was if it "migrated" through the tissue. (much like brine...) but i am not sure bacteria would have enough difference in there chemical makeup to enhance osmosis. (chemist needed here 🙂)

On the outside it is likely you would get an increase but the time the outside is in the critical temperature range should be pretty short. To help this, thaw in the fridge or go straight from freezer to SV, that way there will be minimum buildup on the outside.

Also I think killing bacteria with heat is a time/temperature dependent process. You can sterilize with boiling water (100C) for a very short time but you can achieve the same thing with 65C water for 10 or so minutes. Even at 55C it will kill bacteria but it will take a long time.  (actually like the increase, the decrease is a numbers game. Your body can cope with small amounts of bacteria, so even sterilizing may not kill all the bacteria, jut ~99%?)

[Duvel]

7 hours ago, Bernie said:

The only way for it to get inside was if it "migrated" through the tissue. (much like brine...) but i am not sure bacteria would have enough difference in there chemical makeup to enhance osmosis. (chemist needed here 🙂)

Bacteria are cells and cannot „migrate“ through solid muscle tissue. So, the assessment that with intact muscle fibers (from a properly butchered cut) bacterial contamination would be minimal is correct. Thus for long SV times @rotuts suggestion to sterilize the surface (presear, blanching) is a good idea to minimize bacterial load in the SV bag. 
The two times I had issues with long SV times in both cases I did not tret the surface properly. But - and this might ease your minds - in both cases the bag ballooned up and the failed cook was noticeable before one took a bite. 

[rotuts]

@Bernie

 

""  Your body can cope with small amounts of bacteria "

 

this is both misleading , and completely incorrect .

 

exceptionally small amounts of certain bacteria can be lethal .

 

as this is not Index Medica , Ill leave it at that.

 

 

[gfweb]

16 hours ago, Bernie said:

. Your body can cope with small amounts of bacteria, so even sterilizing may not kill all the bacteria, jut ~99%?)

 

This depends on the type of bacteria and your overall health. Bacteria can also make toxins that cause disease without actually having an infection.

 

Long cooks at low temp is the particular SV worry.

 

 

[Kim Shook]

On 6/21/2024 at 10:10 AM, rotuts said:

@Kim Shook

 

do you want to sear then SV  or SV then sear ?

 

if sear than SV , you might season w just salt and pepper , then sear.

 

you could sear from frozen

 

after sear add granulated garlic , rosemary , Thyme  if you like those flavors.

 

garlic and herbs burn when seared.

 

then bag and SV  135 F  for 6 - 8 hours.

 

if you sear after SV , the roast may over cook ie not be med rare.

 

if searing after SV  , save jus for gravy

 

dry off  , sear quickly   and it will be ready too carve.

 

after SV  the roast does not need to rest.

 

consider pics please.

 

its going to be tasty.

 

remember w SV  time is tenderness.  once love reached your tenderness time , 

 

it can go longer and still  not be over cooked.  certainly by an hour or more.

That all sounds great!  Thank you so much.  I'll be searing first, then SV'ing.  I'll definitely take pictures!  Yesterday I made the beef stock with the rib bones.  I roasted the bones and veg in the CSO and then made the stock in the IP.  I'll be making the actual gravy later today.  

[Slim W]

This link is about a "bad smell" , but I have used this for all long SV and have never had an inflated bag. Seems like a good way to prevent any surface bacteria. 

https://stefangourmet.com/2017/11/01/how-to-prevent-a-bad-smell-with-long-and-low-sous-vide-cooks/