Let's Talk BBQ
Other Cooking Equipment => Other cooking Eqipment => SOUS VIDE COOKING => Topic started by: TentHunteR on September 10, 2014, 09:21:44 AM
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Preface - The Purpose of this Discussion: While neither I nor anyone here are health experts, we owe it to ourselves to stay safe when cooking and posting to this forum. This discussion is the result of months of research, not only by me but teesquare as well. This was not done haphazardly!
There is one particular condition NOT covered by the current sous-vide guides that I've seen: Cold-smoking meat prior to sous-vide cooking.
There may be a sous-vide guide that includes this info, but we haven't seen it and felt, that since we do a lot of smoking around here, this info was needed.
While doing some research on this subject, I took a practice test of the ServSafe certification test. Ironically, one of the questions that came up was about sou-vide.
Here's a screen shot (Click to enlarge):
(https://lh6.googleusercontent.com/-7W-O6-r0b_k/VAfCeHXSV8I/AAAAAAAAHGE/2J4d5e1kP04/s800/SERVSAFE.gif)
Don't Fear Sous-Vide!!!
Please understand, while there is some legitimate concern, this cooking method has been well researched. As long as you adhere to recommended time/temp tables, you can be assured that you are cooking safely!
YOU are responsible for your own health and safety, as well as those you cook for. PLEASE BE SAFE - STICK TO THE MINIMUM TEMPERATURE AND TIME RECOMMENDATIONS!!!
There are a few really good guides out there. This one is considered, by many, to be one of the best: Douglas Baldwin's Sous-Vide Guide (http://www.douglasbaldwin.com/sous-vide.html)
And now, on to our topic.
What prompted me to start looking into this was two different forum members who PM'ed me a few months back asking my opinion on cold-smoking some burgers, then vac-sealing them prior to cooking.
A Few Indisputable Facts:
1) Ground meat, especially pre-packaged, requires some extra precaution, NO MATTER WHAT THE COOKING METHOD.
2) Cold-smoking ANY meat not cured with nitrates/nitrites carries some risks, and special care, NO MATTER WHAT THE COOKING METHOD.
For our purposes, cold-smoking refers to smoking at temperatures below 165° F (74° C).
3) Ground meat, especially, should NEVER be cold-smoked unless it's been cured first with a nitrate/nitrite cure! It's too risky. This is an old sausage maker's rule and Sous Vide does NOT change this!
How does cold-smoking create an extra hazard?
There's a common notion that smoke, alone, will preserve meat. After all, our forefathers and natives preserved meat using smoke, right?
While it's true that smoke contains carbolic acid (phenol), which is a preservative, the meat was typically hung on racks angled over OPEN fires, NOT in a cold-smoke chamber. THERE IS A DISTINCT DIFFERENCE!
Smoking on open racks still allows for oxygen to circulate around the meat. Cold smoking in a BBQ pit or electric smoker, however, creates an oxygen-depleted environment and THIS, combined with the associated temperatures, is where the problems lies. It creates the perfect conditions for anaerobic bacteria to thrive.
What is Anaerobic Bacteria?
Aerobic means "having oxygen." Anaerobic means "lacking oxygen."
so...
Aerobic Bacteria - are those that need oxygen to survive.
Anaerobic Bacteria - do NOT need oxygen, and can survive and/or thrive in an oxygen-depleted environment, depending upon the type.
There are two basic types of Anaerobic Bacteria:
Facultative Anaerobes - such as E. Coli & Salmonella can live in both oxygen rich or oxygen deprived environments. They are not nearly as dangerous as obligate anaerobes when it comes to cold-smoking. This is because in an oxygen-deprived environment, faculative anaerobes simply switch over into a fermentation mode until killed off by pasteurization temperatures.
Facultative Anaerobes - Wikipedia (http://en.wikipedia.org/wiki/Facultative_anaerobic_organism)
However...
Obligate Anaerobes - such as Clostridium Botulinum, given the right temperatures, thrive and reproduce in oxygen deprived conditions. These types of anaerobes are particularly dangerous because as they propagate they release toxic spores which are resistant to temperatures below 230° F
Obligate Anaerobes - Wikipedia (http://en.wikipedia.org/wiki/Obligate_anaerobe)
Why not cold-smoke Ground Meat?
Ground meat is NOT the same as cooking a whole cut of meat. With whole cuts of meat, bacteria that normally lives of the surface gets destroyed quickly enough under normal cooking conditions, to prevent problems. With ground meat, however, that bacteria gets mixed into and throughout the meat when it's ground, so it's now in oxygen deprived conditions. The only thing keeping the anaerobic bacteria in check are refrigeration temperatures of 40° or less.
Under normal cooking conditions, burgers, meat loaf, sausages, etc. are cooked to safe internal temperatures quickly enough to prevent problems.
Cold-smoking uncured ground meat creates a perfect breeding ground for C. Botulinum to propagate and release enough spores to exceed toxic levels. This in turn can cause botulism poisoning which can lead to paralyses and even death.
Botulism - Wikipedia (http://en.wikipedia.org/wiki/Botulism)
How does this tie into Sous-vide?
Sous-Vide temps, given proper time, will pasteurize the meat and reduce anaerobic bacteria to safe levels. HOWEVER, normal Sous Vide cooking temps WILL NOT destroy toxic C. Botulinum spores.
From the Wikipedia sous-vide entry:
...Pasteurization kills the botulism bacteria, but the possibility of hardy botulism spores surviving and reactivating once cool remains a concern as with many preserved foods, however processed...
Consider this for a moment: It's well known that canning green beans, and other non-acidic foods, requires Pressure Canning which allows water to reach high enough temperatures to destroy any possible C. Botulinum spores and toxin.
What Sous-Vide Time & Temps are required to destroy C. Botulinum Spores?
The following FDA data shows that, even with sous vide, C. Botulinum spores (type E.) require an exposure of 100 minutes at 158° F (70° C) for the toxic spores to be destroyed. And, of course, higher temps will destroy them quicker - exposure to temps greater than 230° F (110° C) will destroy the type E. spores in less than 1 second.
Other values to be noted are the D-value of 36.2 min (k = 0.064/min) for Bacillus cereus spores at 95 °C and 100 min (k = 0.023/min) for C. botulinum non-proteolytic Type E spores at 70 °C. When expressed at 110 °C, these D-values become 1.18 min for the B. cereus spores and less than 1 sec for the Type E spores.
Excerpt from: Section 1.2.2.2. - Thermal processes, U.S. FDA Kinetics of Microbial Inactivation for Alternative Food Processing Technologies - FDA (http://www.fda.gov/Food/FoodScienceResearch/SafePracticesforFoodProcesses/ucm100198.htm)
Staying Safe
How can I safely get smoke flavor into ground meats?
There are a couple of easy ways:
1) Add a few drops of liquid smoke to the ground meat and mix it in.
2) Add some smoked paprika to the ground meat and mix it in. Since paprika is a dry product it cannot harbor the food-borne pathogens that cause concern (E. Coli, Salmonilla or C. Botulinum). This trick works great!
What about whole cuts of meat - what's the risk?
Even whole cuts of meat carry extra risk if cold-smoked first.
Your choice here is quite simple. Either:
1) Don't Do it. Instead use a little liquid smoke, or smoked paprika.
3) If you DO risk it, keep your pit as cold as possible, keep it under 30 minutes, and BE ABSOLUTELY SURE TO SEAR THE OUTSIDE OF THE MEAT BEFORE serving it!
Searing temps are normally well above 230°, so a quick sear should take care of any spores present on the outside of the meat.
As with all else, when in doubt - ERR ON THE SIDE OF SAFETY and let common sense rule!
There are more resources available. If you have a good one, PLEASE post it in this thread!
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I hope everyone with ANY interest in Sous Vide will read the above post in the spirit which it is intended.
While it is not the job or responsibility of anyone here to tell you what you should or should not do....I think of the area of risks associated with cold smoking of ground meats in the same fashion as making a sausage that is low temp. smoked.
You need to understand how, when and why curing salts are to be used in order to keep you and more importantly anyone you intend to feed safe.....right?
This is no different. But it is also not commonly discussed.
So if you need to throw rocks or rotten tomatoes...feel free. But I have tossed and turned enough nights trying to collate this information with Cliff into a format that we hope will be received well.
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Thanks for the information gentlemen.
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Thanks for the information gentlemen.
X2! ;)
Very good info thanks for taking the time to research and post it.
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Fine info,thank you very much.VERY much,advice heeded! ;)
For sure I wont cold smoke the burger. But something Im not clear on.
If its safe to smoke while adhering to the 40-140F in 4 hour rule,why wouldnt it be safe to cold smoke,say ambient temp about 60F or less for an hour or so before SV on whole muscle meat?
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Thanks for all your research on this subject. I'm new to SV and need all the safe info I can handle. Thanks again. Pam .☆´¯`•.¸¸. ི♥ྀ.
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Good information!
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Great information! Thanks Cliff and Tim!
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Thank you gentlemen! Your hard work on this important subject matter is greatly appreciated! ;)
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http://texasbbqforum.com/viewtopic.php?f=2&t=24513
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This information is great. If you have not already done so, I recommend saving the Douglas-Baldwin link, and then look at the videos. I learned a lot, and am still learning about sous vide. This is the best guide that I have seen out there so far. Thanks for posting.
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This is a really good question!
...something Im not clear on.
If its safe to smoke while adhering to the 40-140F in 4 hour rule,why wouldnt it be safe to cold smoke,say ambient temp about 60F or less for an hour or so before SV on whole muscle meat?
First, as far as I'm aware that "get to 140° within 4 hours" rule generally applies to Hot-smoke temps of 165° or greater, NOT cold-smoke temps.
Second, from a safety standpoint, even with a 60° pit temp, there is still at least a nominal risk when cold-smoking ANY uncured meat.
A 60° pit seems cool to you and me, but it's just within the optimal temperature range for rapid C. Botulinum growth.
(https://lh4.googleusercontent.com/-87GQfJ6qXWk/VBDeLlz9iOI/AAAAAAAAHIg/zzxiNENmN5I/s629/CBotGrowth.gif)
Based on findings in: "Effect of temperature on... cell growth of Clostridium Botulinum." (http://www.ncbi.nlm.nih.gov/pmc/articles/PMC241827/)
So, as I mentioned above, if you DO choose to cold-smoke a whole cut of meat prior to sous-vide, then I'd keep my pit as cool as possible and I'd be sure to sear the outside of the meat really well before serving.
Hope this makes sense!
Cliff
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Thanks Cliff. ;)
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Excellent information and back up research - very well presented. Thank you!
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Great job, Cliff! When I get back from the beach I will look into my ServSafe book to see if there is anything to add to your research.
Art
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Dumb question here...What if you partially froze the meat before cold smoking? Like half and hour to an hour, depending on size and thickness of meat. just sayin. Pam .☆´¯`•.¸¸. ི♥ྀ.
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Dumb question here...What if you partially froze the meat before cold smoking? Like half and hour to an hour, depending on size and thickness of meat. just sayin. Pam .☆´¯`•.¸¸. ི♥ྀ.
I would think, that anything that helps to keep the surface temperature of whole cuts of meat below 43° has got to help reduce the risk. How well smoke will stick to a partially frozen piece of meat, I can't say.
Also keep in mind that freezing will NOT destroy C. Botulinum spores; they simply remain dormant until the right temperature & conditions are met. So even if frozen, I'd still limit cold-smoking to around 30 minutes or so, just to err on the side of safety, and I'd still sear it off before serving.
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Thanks for the information. This backyard jack needs all the help he can get to keep from makin' folks sick.
I think we would be remiss if we DIDN'T have this little talk.
Good to know y'all are lookin' out for us.
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It's a balmy 10º right now..it's time to cold smoke something..like meat, cheeses etc. Pam GO BUCKS .☆´¯`•.¸¸. ི♥ྀ.