Problem cooking sous vide brisket

[Richard Russell]

Hello all,

 

I just cooked a rolled brisket sous vide for 22 hours at 56C (132.8F).

 

It came out with air in the bag, covered in green-brown slime, and smelling like ... baby poo. I cut away the surface to get to the meat underneath, which looked bland and tasted OK, but certainly wasn't appealing. Needless to say, it didn't get eaten.

 

But I want to know what happened, and whether this was a health risk.

 

The butcher I bought the cut from is well known for premium quality. They have their own farm and dry-age their meat. This was clearly aged, one edge being particularly dark. It was tied with string, as rolled brisket often is. They vacuum-packed it (with string still on) for me, and there was no air in the bag. It was a warm day, and I walked 20 mins home, then put it straight into the fridge. A few hours later, I dropped it into 56C (132.8F) water, which was kept at a constant temperature by an Anova circulator. I covered the pot with aluminium foil and some tea towels to insulate against heat loss.

 

22 hours after that, I opened it up, mouth watering. The bag had some air in it (maybe 50mL or so - not at pressure, but more than just a few bubbles). The meat had shrunk, and the bag had a quantity of blood and juices in it (maybe 100mL) - this was expected. Opening it revealed a rather unpleasant smell. It didn't smell entirely toxic, but it didn't smell edible (those with babies will know what I mean). There was a layer of green-brown slime on the meat. I mostly washed it off the fat, but I couldn't wash it off the meat. I cut the edges off, revealing tender pink-grey meat on the inside. The meat from the inside didn't smell bad, but didn't smell good either. Taste and texture was bland. My fingers still smell of the slime, even after washing.

 

I did a bit of searching, and found something on another site (which Chrome currently gives me a malware warning for) here. However, there's no real conclusions there as to what happened, whether it was a health risk, or how to prevent it. They also have a photo here. I didn't take a photo, but mine was similar though less green. Maybe more yellow-brown than that.

 

Can anyone help me out here?

 

What happened?

 

Was this dangerous, or just unpleasant?

 

How do I avoid this in future?

 

Thanks

[Lisa Shock]

I'd say the 'air' was gas created as a by-product of some sort of anaerobic bacteria or other micro-beastie. Looks like your body fought it off and/or wasn't affected too badly by any toxins it produced. But, this could have been bad. You're cooking in the danger zone (4or5 - 60C) with plenty of moisture and protein and some sugars available to feed the bugs. Be aware that some bad bugs, like botulism, have no odor and a small amount of their toxin is deadly. I'd toss any bag that produced an air/gas bubble like yours did.

 

Don't most methods call for some sort of procedure to sterilize the outside of the meat? You don't mention a sear or dip in boiling water, or starting at a high temp. -I think you need this step to prevent what just happened.

[jayt90]

It probably should be sterilized before rolling and tying.

[Richard Russell]

I'd say the 'air' was gas created as a by-product of some sort of anaerobic bacteria or other micro-beastie. Looks like your body fought it off and/or wasn't affected too badly by any toxins it produced. But, this could have been bad. You're cooking in the danger zone (4or5 - 60C) with plenty of moisture and protein and some sugars available to feed the bugs. Be aware that some bad bugs, like botulism, have no odor and a small amount of their toxin is deadly. I'd toss any bag that produced an air/gas bubble like yours did.

 

Don't most methods call for some sort of procedure to sterilize the outside of the meat? You don't mention a sear or dip in boiling water, or starting at a high temp. -I think you need this step to prevent what just happened.

 

Hi Lisa,

 

I didn't eat it. I tasted some of the interior flesh, and was careful to avoid any that had come into contact with the juice. So far, I feel fine.

 

I haven't come across any advice to sterilise first. I've done steaks at a similar temperature (in fact, a few degrees lower) for two hours, and they were great. I follow the water bath with a high temperature sear, as I intended to do with this brisket.

 

Cheers

 

Richard

[MSRadell]

I'm quite sure that the bag actually had quite a bit of air in it when you started.  Since the brisket was rolled and not vacuum packed flat there is quite a bit of space between the layers and in the middle where the are really can't be evacuated completely.  That amount of air combined with the temperatures you cooked at and any possible bacteria on the meat combined during the cooking process to create what you found when you opened the bag.  It's actually hard to say what kind of bacteria created the problem.

[paulraphael]

Since you said green-brown slime and dry aging, I'm wondering if it was actually some form of mold. There aren't any bacterial pathogens that reproduce at 56C, so I don't believe that bacteria would be the issue. Technically your meat should have been pasteurized within 6 hours of reaching 55C. 

 

But I never hear anyone talk about mold (or algae) when coming up with food pasteurization tables. Dry aging often encourages mold growth on the outside of the meat. It's cut away with the dessicated outer portions, but this isn't done under sterile conditions. The question is if there's any mold that grows in both the medium humidity and sub-4°C environment of dry aging, and the 100% humidity and 56C environment of your sous-vide bag.

 

It's a new one to me. I don't believe you did anything that would raise a red flag, but many people choose to sear or blanch meat before any long, low-temp cook.

 

I'd suggest doing this in the future. But it doesn't answer your question directly. I can just offer another guess as to what happened.

[Shalmanese]

The problem is you rolled it. The interior of (non-jaccarded) meat is sterile, only the surface of meat has pathogens. For standard flat cut of meat, the surface goes from 4C -> 130C fairly quickly and any pathogens have barely enough time to breed before dying. For a rolled piece of meat, the surfaces in the center take a very long time to reach 130C and it's likely some pathogen in the middle was quickly reproducing while it was coming up to temp. All of the pathogens would have been dead after a 22 hour cook but the byproducts remain. There's no telling if they were actually harmful or not but it's irrelevant since they're undesirable.

 

There's no good reason to cook meat rolled in SV, pasteurization time increases as the square of maximum thickness so you want your foods to be as thin as possible. If you really insist on rolling, blanch the outside of the meat in boiling water before rolling and sealing.

[gfweb]

This is correct. A rolled piece of meat puts the outside inside, so to speak. Not a great idea to cook it SV without a dip in boiling water before rolling.

[dcarch]

Also check the temperature calibration of your setup just to be sure.

 

dcarch

[paulraphael]

Shalmanes's explanation makes more sense than the mold idea. It's an interesting point ... should be obvious, but I've never seen rolling meat mentioned specifically as something to avoid.

[Lisa Shock]

The problem is you rolled it. The interior of (non-jaccarded) meat is sterile, only the surface of meat has pathogens. For standard flat cut of meat, the surface goes from 4C -> 130C fairly quickly and any pathogens have barely enough time to breed before dying. For a rolled piece of meat, the surfaces in the center take a very long time to reach 130C and it's likely some pathogen in the middle was quickly reproducing while it was coming up to temp. All of the pathogens would have been dead after a 22 hour cook but the byproducts remain. There's no telling if they were actually harmful or not but it's irrelevant since they're undesirable.

 

There's no good reason to cook meat rolled in SV, pasteurization time increases as the square of maximum thickness so you want your foods to be as thin as possible. If you really insist on rolling, blanch the outside of the meat in boiling water before rolling and sealing.

 

Overall I agree with your assessment, but would like to point out that it never went to your 130C. The OP stated that he ran it at 56C for 22 hours. Also, most health departments recommend tossing meats that have been in the danger zone for more than 4 hours. If it took 6+ hours to get inner parts of the roll, which were formerly outer parts of the meat, to 55-56C, that's too long.

[Richard Russell]

I also like the theory about pathogens on the inside of rolled meat, but there was no evidence of anything growing on the "inside" of the roll. All the growth was on the external surface, which would have been at 56C almost immediately after being put in the water bath. Personally, I'm still puzzled as to what this could be. I am down to assuming that there was something added to the surface during vacuum packing, perhaps from the hands of the butcher?

 

I think next time, I'll do an unrolled one, with no string, and maybe will brown or blanch it first to kill anything on the surface. This means I'll be using a ziploc bag rather than a professional vacuum packer, but also means I can add some extra flavouring.

[Anna N]

Overall I agree with your assessment, but would like to point out that it never went to your 130C. The OP stated that he ran it at 56C for 22 hours. Also, most health departments recommend tossing meats that have been in the danger zone for more than 4 hours. If it took 6+ hours to get inner parts of the roll, which were formerly outer parts of the meat, to 55-56C, that's too long.

I am sure there's a typo or two going on here. 130 C is an unreasonable temperature for SV.

[Richard Russell]

I am sure there's a typo or two going on here. 130 C is an unreasonable temperature for SV.

I am sure 130F (54.5C) was meant. If meat gets to 130C, it's inedible and dry (unless it's part of the crust on the surface).

Edited May 19, 2014 by Richard Russell (log)

[gfweb]

I think next time, I'll do an unrolled one, with no string, and maybe will brown or blanch it first to kill anything on the surface. This means I'll be using a ziploc bag rather than a professional vacuum packer, but also means I can add some extra flavouring.

You can still vacuum pack, just dip meat in the boiling water before putting in the bag..

[Richard Russell]

You can still vacuum pack, just dip meat in the boiling water before putting in the bag..

Not without a vacuum packer, I can't... The butcher vacuum packed it for me, but I don't think they'll dip it in boiling water before they vacuum pack it...

[gfweb]

Ah.  Well, nothing magic about vacuum as far as SV goes. I have one but don't use it for most SV stuff I'm going to cook and eat.

[mgaretz]

I've done quite a few long SV cooks of chuck, and it will have a greenish layer on the outside. This changes back to brown when you sear it. However it doesn't smell bad.

[EnriqueB]

Not without a vacuum packer, I can't... The butcher vacuum packed it for me, but I don't think they'll dip it in boiling water before they vacuum pack it...

 

Why can't you dip the already vacuum packed meat into the boiling water? Is it because those bags aren't rated for 100ºC?

[paulraphael]

Why can't you dip the already vacuum packed meat into the boiling water? Is it because those bags aren't rated for 100ºC?

The issue is that the brisket was rolled before vacuum packing. If you want to do it this way, then dipping the bagged brisket in boiling water will still only heat the portions that are currently on the outside.

 

I would just dispense with the vacuum packing. It's not necessary. Use a big ziplock or an oven bag, with a little liquid added (stock, etc.). Evacuate the air by immersing it. There's really no downside.

[gfweb]

I've done quite a few long SV cooks of chuck, and it will have a greenish layer on the outside. This changes back to brown when you sear it. However it doesn't smell bad.

Me too. It was the smell that was suspicious to me as well.

[rotuts]

""   dry-age their meat  ""

 

i think something might have happened in the dry age process.

 

cant be sure.   I do long SV times, 48 - 72.  even after a short 3 - 4 day refrigerator aging in my own refrigerator of 'fresh' meat.

 

I make sure its packed that day at the butcher, a mega-mart like store.  I never by 'on sale' meat nears its exp for any sort of SV.

 

Ive never had a problem.  i think the smell and extra air is a dead give away that something is wrong

[Michael S.]

IIRC, some of the liquid will change phase to a gas in a vacuum bag since the boiling point is lower, so that is likely where the gas came from. The above about surface bacteria ending up in the middle at a nice cosy temperature for a long time would account for the smell and gunge.

[paulraphael]

Interesting: Microbial deterioration of vacuum-packaged chilled beef cuts and techniques for microbiota detection and characterization: a review

 

"Clostridium and Enterobacteriaceae (5), can multiply in vacuum-packaged meat causing deterioration and pack distension at refrigeration temperatures. These microorganisms have been the subject of many studies. Species of Clostridium that are able to grow at refrigeration temperatures have been identified as causative agents of blowing vacuum packages. Recently, new genera, such as Enterobacteriaceae, have also been shown to cause the same problem"

 

"The deterioration caused by psychrotrophic and psychrophilic Clostridium is associated with proteolysis, loss of texture, accumulation of liquid in packages and an unpleasant smell, mainly hydrogen sulfide gas (55). In anaerobic conditions, proteins are degraded into sulfur compounds, which have strong and disgusting odor. End products of non-protein nitrogen compounds generally include ammonia (34)."

 

"The deterioration of vacuum-packaged meat caused by Enterobacteriaceae bacteria is often characterized by unpleasant odors and / or greening of the meat, instead of gas production (5). The proliferation of this bacterium in vacuumpacked meat is generally limited to products with a pH greater than 5.8 (28) and is more likely to occur with temperature abuses (5) above 6ºC (36). Enterobacteriaceae species that grow in vacuum-packed meat (Serratia liquefaciens, Hafnia spp) are able to grow at temperatures between 0 and 10ºC (43). At temperatures above 6ºC, Enterobacteriaceae decarboxylate amino acids, producing organic amines, which have putrid odors and tastes."

 

"Vacuum packages for fresh meat increase the shelf life and thus improve the distribution efficiency and marketing of the product. Deterioration problems are minimized when the pH of the meat to be packaged is controlled and ideal storage temperatures are accurately maintained. Even at suitable refrigeration temperatures, however, meat may be subject to deterioration by microorganisms that are able to grow under these conditions in the absence of oxygen. Psychrotrophic and psychrophilic Clostridium species have been shown to cause blown pack type of deterioration; however, other species that produce CO2 such as Enterobacter, Serratia, Hafnia and Rahnella may also contribute. There has been little research on these organisms, especially those that cause the blown pack problem."

[gfweb]

IIRC, some of the liquid will change phase to a gas in a vacuum bag since the boiling point is lower, so that is likely where the gas came from. The above about surface bacteria ending up in the middle at a nice cosy temperature for a long time would account for the smell and gunge.

Don't think that this is true. The term Sous Vide is a misnomer.  The bag interior is not in a true vacuum, the free air around the food is sucked out, but the bag interior is not under negative pressure so BP for a liquid will not change.

 

Meat will contract a little with cooking and that can make it appear as though there is a little airpocket, but most of  the space around the contracted meat will be filled with  (tasty) juices.

 

It shouldn't smell like anything but food.