Temperature Probe Insertion Question -- Timing

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thrifty token

Smoke Blower
Original poster
Jul 10, 2012
81
13
Dedham, MA
Ok, after trolling the Forum for awhile, I'm am now confused about when to insert the temp probe into a pork shoulder or brisket.  Seems there are 2 recommendations: 1) Insert at beginning of smoke, or 2) Insert around 4 hours later.  I believe this is due to food safety concerns.  I believe these concerns are cured when the internal temp reaches 140 degrees w/i 4 hours?

Question:  Does it really matter when the probe is inserted?

Thanks for your feedback.  Have a great Labor Day! ~~ Thrifty
 
If you insert the probe at the beginning, you may be pushing surface bacteria deep into the meat where the temp may not reach 140° within 4 hours to kill it.

I believe the concensus was that it was ok to insert after 1 hour, the reason being that the surface temp would be over 140° by then and any stray bacteria would already be dead. Or, alternately, at the begining, using a propane torch to cauterize a small spot where you intend to insert the probe.
 
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I don't insert the probe for the first 2 hours - just a safety thing with me - still gives me 2 hours if things are going slower than I want 
 
I usually wait to check the temp until 4-5 hours on a 8-10 lb butt.
 
Thanks for the feedback.  Next Boston butt I smoke, I'll wait before inserting the probe.  I love this Forum!  
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If you insert the probe at the beginning, you may be pushing surface bacteria deep into the meat where the temp may not reach 140° within 4 hours to kill it.

I believe the concensus was that it was ok to insert after 1 hour, the reason being that the surface temp would be over 140° by then and any stray bacteria would already be dead. Or, alternately, at the begining, using a propane torch to cauterize a small spot where you intend to insert the probe.
 This is where I am on the subject. I usually have the Torch out for my AMNPS anyway...JJ
 
I am a bit confused on this topic.   It is my understanding that if you cook anything and keep it over 160 or so for over 10 minutes ALL bacteria will be inactivated in the process.   If you are gooking a pork butt that will be cooked until the IT gets to 205 or 210 it will spend hours over 160.   At that point what difference would it make that a few bacteria made their way into the center of the meat on the probe - they will all be inactivated just like the ones on the surface.

Tom
 
I think mneeley and JJ said it all!

Just because you heat it above 160* for 10 mins isn't going to kill everything!

If the surface is compromised in any way and it stays in the danger zone (40*-140*) for more than 4 hours you are running a risk no matter how hot you get it.

Would you leave a piece of meat out in the sun for a week then heat it above 160* and think it would be safe?
 
You are missing the point. The meat is cooking far beyond 160, and for several hours. So it justifies a discussion to flush out thoughts. If I'm off base then say so, otherwise proof read your posts before you go off halfcocked.
 
If you insert the probe at the beginning, you may be pushing surface bacteria deep into the meat where the temp may not reach 140° within 4 hours to kill it.
I believe the concensus was that it was ok to insert after 1 hour, the reason being that the surface temp would be over 140° by then and any stray bacteria would already be dead. Or, alternately, at the begining, using a propane torch to cauterize a small spot where you intend to insert the probe.
Great idea.. would have never thought of that until now!
Thanks
Mike
 
I am a bit confused on this topic.   It is my understanding that if you cook anything and keep it over 160 or so for over 10 minutes ALL bacteria will be inactivated in the process.   If you are gooking a pork butt that will be cooked until the IT gets to 205 or 210 it will spend hours over 160.   At that point what difference would it make that a few bacteria made their way into the center of the meat on the probe - they will all be inactivated just like the ones on the surface.

Tom
Interesting point, are there any comments? I like to hear what other say.
You are missing the point. The meat is cooking far beyond 160, and for several hours. So it justifies a discussion to flush out thoughts. If I'm off base then say so, otherwise proof read your posts before you go off halfcocked.
This is easily answered and no one missed the point...There are thousands of types of Bacteria most or all ARE killed at 160*F in a matter of seconds or more....BUT...The most dangerous to humans have two tricks! They can make Toxins that maim or kill in very tiny amounts. There are also many that form Spores or a protective shell that allows them survive chemicals and heat well in excess of 210*F. Spore formation is triggered buy Low and Slow cooking like making Pulled Pork, a Brisket and smoking an Enhanced Turkey over 14Lbs. We need extra caution with smoking temps under 225*F and should make use of a Nitrite Cure, especially Jerky Production and Sausage Making! Clostridium Botulinum is just 1 such tricky SOB that is found in Dirt, on any Herb and Vegetable or food source fit for Man or Animal that is grown in dirt. It is common on skin and EXTREMELY abundant in Animal Feces including yours! In other words if the animal is slaughtered for human consumption and any part of the Digestive Tract is pierced or cut the Meat is very likely Contaminated with stomach contents and feces which is Natures Incubator dumping BILLIONS of this CB Bacteria onto the meat. The Bug (harmless except to Babies under 1, Old people and the Immune deficient) is killed at 165*F but the Toxin, the part that KILLS remains until the meat gets above 212*F (Pulled Pork gets Mushy above 205*F) and lastly the Spores are not heat sensitive at all so they are just waiting for you to mishandle the leftovers! Here is a brief list of the most common and some handling info to avoid contamination and cross-contamination. It is educational material and not copyrighted for personal use. I hope this clears up the, " If I cook it, I will be Fine..." misconceptions. The fact is YES most of the time, " Grandma Defrosted the Turkey on the Counter for 75 years and nobody got sick or died..." you will get away with defrosting on the counter, injecting or boning out the meat or even probing the meat but every once in a while every time the meat surface gets too warm (above 40*F) and/or is broken...Bacteria gets pushed in and cooking to 160*+F will still not make it safe...JJ ( Fully Cocked and Locked Certified Food Safety Instructor 
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The first step in preventing food poisoning is to assume that all foods may cause food-borne illness. Follow these steps to prevent food poisoning:
  1. Wash hands, food preparation surfaces and utensils thoroughly before and after handling raw foods to prevent recontamination of cooked foods.
  2. Keep refrigerated foods below 40 degrees F.
  3. Serve hot foods immediately or keep them heated above 140 degrees F.
  4. Divide large volumes of food into small portions for rapid cooling in the refrigerator. Hot, bulky foods in the refrigerator can raise the temperature of foods already cooled.
  5. Remember the danger zone is between 40 degrees F and 140 degrees F.
  6. Follow approved home-canning procedures. These can be obtained from the Extension Service or from USDA bulletins.
  7. Heat canned foods thoroughly before tasting.
  8. When in doubt, throw it out
Infants, older persons, women who are pregnant and anyone with a compromised immune system are especially susceptible to food-borne illness. These people should never consume raw fish, raw seafood, or raw meat type products.

You are the key to preventing food-borne illness. By observing the simple rules of good handling, food poisoning can be eliminated.
Bacteria ResponsibleDescriptionHabitatTypes of FoodsSymptomsCauseTemperture Sensitivity
Staphylococcus aureusProduces a heat-stable toxinNose and throat of 30 to 50 percent of healthy population; also skin and superficial wounds.Meat and seafood salads, sandwich spreads and high salt foods.Nausea, vomiting and diarrhea within 4 to 6 hours. No fever.Poor personal hygiene and subsequent temperature abuse.No growth below 40° F. Bacteria are destroyed by normal cooking but toxin is heat-stable.
SalmonellaProduces an intestinal infectionIntestinal tracts of animals and manHigh protein foods – meat, poultry, fish and eggs.Diarrhea nausea, chills, vomiting and fever within 12 to 24 hours.Contamination of ready-to-eat foods, insufficient cooking and recontamination of cooked foods.No growth below 40° F. Bacteria are destroyed by normal cooking.
Clostridium perfringensProduces a spore and prefers low oxygen atmosphere. Live cells must be ingested.Dust, soil and gastrointestinal tracts of animals and man.Meat and poultry dishes, sauces and gravies.Cramps and diarrhea within 12 to 24 hours. No vomiting or fever.Improper temperature control of hot foods, and recontamination.No growth below 40 degrees F. Bacteria are killed by normal cooking but a heat-stable spore can survive.
Clostridium botulinumProduces a spore and requires a low oxygen atmosphere. Produces a heat-sensitive toxin.Soils, plants, marine sediments and fish.Home-canned foods.Blurred vision, respiratory distress and possible DEATH.Improper methods of home-processing foods.Type E and Type B can grow at 38° F. Bacteria destroyed by cooking and the toxin is destroyed by boiling for 5 to 10 minutes. Heat-resistant spore can survive.
Vibrio parahaemolyticusRequires salt for growth.Fish and shellfishRaw and cooked seafood.Diarrhea, cramps, vomiting, headache and fever within 12 to 24 hours.Recontamination of cooked foods or eating raw seafood.No growth below 40° F. Bacteria killed by normal cooking.
Bacillus cereusProduces a spore and grows in normal oxygen atmosphere.Soil, dust and spices.Starchy food.Mild case of diarrhea and some nausea within 12 to 24 hours.Improper holding and storage temperatures after cooking.No growth below 40° F. Bacteria killed by normal cooking, but heat-resistant spore can survive.
Listeria monocytogenesSurvives adverse conditions for long time periods.Soil, vegetation and water. Can survive for long periods in soil and plant materials.Milk, soft cheeses, vegetables fertilized with manure.Mimics meningitis. Immuno-compromised individuals most susceptible.Contaminated raw products.Grows at refrigeration (38-40° F) temperatures. May survive minimum pasturization tempertures (161° F for 15 seconds.)
Campylobacter jejuniOxygen sensitive, does not grow below 86° F.Animal reservoirs and foods of animal origin.Meat, poulty, milk, and mushrooms.Diarrhea, abdomianl cramps and nausea.Improper pasteuriztion or cooking. Cross-contamination.Sensitive to drying or freezing. Survives in milk and water at 39° F for several weeks.
Versinia enterocoliticaNot frequent cause of human infection.Poultry, beef, swine. Isolated only in human pathogen.Milk, tofu, and pork.Diarrhea, abdominal pain, vomiting. Mimics appendicitis.Improper cooking. Cross-contamination.Grows at refrigeration temperatures (35-40° F) Sensitive to heat (122° F)
Enteropathogenic E. coliCan produce toxins that are heat stable and others that are heat-sensitive.Feces of infected humans.Meat and cheeses.Diarrhea, abdominal cramps, no fever.Inadequate cooking. Recontamination of cooked product.Organisms can be controlled by heating. Can grow at refrigeration temperatures.
Bacterial Reference Table
The information given herein is for educational purposes only. Reference to commercial products or trade names is made with the understanding that no discrimination is intended and no endorsement by the Texas AgriLife Extension Service is implied.

Educational programs of the Texas AgriLife Extension Service are open to all people without regard to race, color, sex, disability, religion, age, or national origin.

Publication Revised November 2008

 
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The other important consideration:

Metal conducts heat significantly better than meat. the metal body of the probe also acts as a heat conducting pin. The more metal in the probe the more it conducts heat. The longer it stays in the meat the more heat it delivers to the meat.

What you are measuring with a heavy probe in a long cook will be very distorted. The meat away from the probe may be at a much lower temperature.

dcarch
 
The other important consideration:

Metal conducts heat significantly better than meat. the metal body of the probe also acts as a heat conducting pin. The more metal in the probe the more it conducts heat. The longer it stays in the meat the more heat it delivers to the meat.

What you are measuring with a heavy probe in a long cook will be very distorted. The meat away from the probe may be at a much lower temperature.

dcarch
That is why the probe is only a guide. You need a secondary way of telling the temp in other areas, being either moving the probe or using a second thermometer. Budget usually determines what people do there.

But with that being said in over 20 years cooking professionally and using probes to monitor during cooks countless times. I have never seen where it has made that much of a difference with having a 3"-6" x 1/8" piece of metal in the meat. Not saying it does not make a slight difference, but it is not noticeable. Any of the heat that may transfer from the probe to the meat is lost very quickly. They are designed to not transfer the heat. They are hollow and if they did allow heat to transfer they would not be anywhere accurate and pointless to make, sell and use. If you look at the probe you will see a little mark close to the tip. From that point to the tip is all the reads the temp. Now if the probe was to be a heating element inserted into the meat, that is a whole other subject.
 
I use probe wipes and or sanitiser, these kill / reduce the amount of potential pathogens, on a probe.  

At a temperature of 75°c - 172°f  any bacteria present will have been destroyed or reduced to a safe level.  Any bacteria on the outside of the food item, will be subject to the same conditions as any bacteria on the inside.  

How many of us sanitise the needle that we use to inject liquids into the meat before cooking?  Just wondering.

Gary
 
Wiping the Needle is just one more step to ensure safety. But as I tried to point out the Bacteria we most worry about is on the surface of the meat. So even a brand new, freshly out of the package, Certified Sterile needle will still push surface bacteria into the meat. This is no big deal MOST of the time as you pointed out bacteria is dead at temps above 170*F...BUT...It remains, thing still go wrong and it is not the Bacteria that is always harmful but the Toxins they produce Before the heat kills them...JJ
 
Thanks JimmyJ - that is the most clear explanation that I have seen so far.   I will certainly follow the recommendation of waiting a few hours to insert the thermometer.  

I remain curious however as to the mechanism that removes the risk of contamination.   If I am making pulled pork at a smoker temp of 225 or so, are we counting on the surface temp of the meat going above 212 in the first two hours, thus inactivating even the spore or oocyst forms of various pathogens?   Are all such bad actors inactivated above 212?  The list above hints at the temps but does not give them.  The method of torching a patch seems to support this concept but variations in how this is done could cause issues.

I work in the water treatment industry and we learned a valuable lesson about cryptosporidium in the 1990s when the oocyst's resistance to chlorine inactivation killed a lot of people.   I think most of us think of meat bacteria as being easy to deal with as we are told about 160 degrees being the standard for safety, so my guess is that I have been lucky over time in that I have violated the guidelines you have identified many times, but will not going forward.

Thanks

Tom
 
Here in the UK it's 75° or 172°f  and would be taken in the thickest / most dense part of the food.  (there are exceptions)   I would hazard a guess and say there wouldn't be many people who have not broken the guidelines at some point, I know I have!

Do you guys also torch the patch before you inject fluids into the meat before cooking??
 
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