I understand the 4 hour rule, but......

Discussion in 'Food Safety' started by udt89, Nov 16, 2010.

  1. udt89

    udt89 Newbie

    when reading around the site I see people stating they are at a constant 250 degrees for X hours.  Didnt I read in this forum somewhere to get to the required temp in 4 hours you need to be at 275?

    also, just to confirm, putting a temperature probe into a meat while it is still uncooked changes the rules?  So is that what you guys are doing?  Not probing the meat until after the first 4 hours since it is considered intact?

    Hope that makes sense
  2. alblancher

    alblancher Master of the Pit Group Lead OTBS Member

    You do not want the meat to be within 40 to 140 degrees for more than 4 hours.  You also want the outside of the meat to be exposed to 240-250 degree temps fairly rapidly.to kill anything on the outside of the meat. 

    The deal about putting a temp probe in also confuses me some.  If you insert a clean temp probe into a piece of meat that is contaminated on the outside the meat will now be contaminated on the inside also.  Most people allow whole cuts to smoke for a couple of hours (allowing surface temps to get past 140) before inserting the temp probe.   Poultry on the other hand is considered contaminated from the get go so the temp probe is often inserted while still cold.  This helps seal the probe hole and allow the poultry to retain more moisture.
    Last edited: Nov 16, 2010
  3. arnie

    arnie Smoking Fanatic

    The 4 hour rule, if I understand it correctly, says whole muscle meat needs to be 140⁰ within 4 hours. I believe it is 3 hours for ground meat. If a temp probe is used at the beginning of the smoke the 3 hour rule applies. If you are sure it will take more than 3 hours to bring the meat temp to 140⁰ the temp probe should not be inserted until the surface temp of the meat reaches 140⁰, which can be checked with a noncontact temp probe. I do the majority of my smoking at 225⁰. On larger cuts of meat I will give them an hour to an hour and a half before I wipe my temp probe with a Clorox Wipe and insert it.
  4. pineywoods

    pineywoods Smoking Guru Staff Member Administrator Group Lead SMF Premier Member

    40-140 internal for any ground meat or meat that has been injected or had the thermometer probe placed in it before the smoke starts.

    The intact muscle rule says 40-140 in the outer 1/2" in under 4 hours.
  5. chefrob

    chefrob Master of the Pit OTBS Member

    to answer some of the original poster's questions.....
    if you did, that is incorrect.....the time to reach a certain internal temp will be determined by:

    1) the temp of the smoker

    2) the thickness or mass density of the food item

    3) if there is a bone in the cut of meat
     that depends on whether or not the surface temp is above 140........i would go 165 to cover ground meats. to be truthfull the only thing i take temps on are poultry items.......as you gain more confidence in your cooking skills you will learn to rely on your sense of touch, sight, and timing for most items.

     hope some of this helps...........
  6. udt89

    udt89 Newbie

    so if i were smoking a turkey putting the temp probe in cold is the proper way to do it.

    if i were doing brisket or pork, I should wait till the outside temp is 140? or 165 before putting in a temp probe? or somewhere in that range
  7. alblancher

    alblancher Master of the Pit Group Lead OTBS Member

    It's pretty common to wait only a couple of hours before inserting a temp probe into a whole cut of beef.  The surface area gets pretty hot pretty fast because the smoker temp is in the 240 degree range.  You will have a hard time waiting until the internal temp is 140 before inserting the probe because when talking about briskets and chuckies 140 is close to the final cooking temps.

    Jeff (the owner of the site) and many other respected posters insert the themos in poultry before placing on the smoker.  But we do not cook poultry rare.  Look at this months newsletter.  There is a good article on smoking a turkey.

  8. bearcarver

    bearcarver Smoking Guru OTBS Member

    What Pineywoods said.

    If you were reading 275˚, it was probably about Turkey smoking.

  9. alblancher

    alblancher Master of the Pit Group Lead OTBS Member

    You may wish to pm Bbally if you have a specific question about one of his posts.  I don't have a problem injecting whole muscle meat because I bring my injection marinade up to temp before loading the syringe.   I also think that the cross section of a hypodermic needle is so small, that a very small number of living pathogens are transferred into the muscle meat. 

    I believe the size of the population of bad germs is important when trying to determine safety standards.   During food safety standard development a sample size of pathogens is determined, the test surface is inoculated and the amount of time it takes for the population of bugs to reach an unsafe level is determined at different temperatures.  These tests lead to standards for safe food handling.  Food scientists need to estimate just how much bad bacteria can be found on fresh cuts of processed meat to determine how long it will take for them to reach an unsafe population if not handled properly 

    The amount of pathogens transferred into whole muscle meat by a syringe needle is very small.  It takes a longer time for those few bacteria to reach an unsafe level.  By that time (4 + hours) the internal temps are reached and the small population of pathogens is killed before potentially dangerous residual toxin levels or pathogenic populations are reach

    On the other hand,  using a syringe to inject marinade into whole muscle meat and then leaving it in the danger zone for an extended period of time without some additional treatment (cure) will allow an unsafe pathogen population to develop.

    The best example is using a meat tenderizer that uses scores of needles to cut the tissue.  That previously whole muscle must be treated like hamburger because you are transferring a large number of bacteria into the muscle.  It will not take very long for a dangerous population of bacteria to develop if not brought to safe temperature rapidly.
  10. deannc

    deannc Master of the Pit

    The following is copied from the USDA web site. (USDA Smoking Meat and Poultry)

    "Use Two Thermometers to Smoke Food Safely To ensure meat and poultry are smoked safely, you'll need two types of thermometers: one for the food and one for the smoker. A thermometer is needed to monitor the air temperature in the smoker or grill to be sure the heat stays between 225 and 300 °F throughout the cooking process. Many smokers have built-in thermometers. Use a food thermometer to determine the temperature of the meat or poultry. Oven-safe thermometers can be inserted in the meat and remain there during smoking. Use an instant-read thermometer after the meat is taken out of the smoker."

    Over the last several months I've searched the USDA site and the Safe Food Handling Fact Sheets trying to find where it is discussed about the meat reaching 140* within 4 hours.  Can someone provide a link?

    I underlined the section above where it refers to inserting a meat thermometer.  It states here that a thermometer can be inserted in the meat and remain there during smoking.  Is there another area on the USDA site that gives the specifics about puncturing with a probe before reaching 140*?

    Not trying to contradict any posted information, just trying to satisfy my own curiousity and find specific references as I've always read this information posted in the forum but haven't been able to find it in the USDA site. 
  11. chefrob

    chefrob Master of the Pit OTBS Member

    this is what bob wrote...........
     there were specific questions in that thread that are no longer there that he reponded to so i certainly do not want to speculate what he was trying to explain but it sounded like some one was asking about a cut of meat that was injected and he was addressing what temp for that SPECIFIC cut to pass through the danger zone in a safe manner. again i do not know what te original question was.............

    it could have been a butt...........i do not know.
  12. chefrob

    chefrob Master of the Pit OTBS Member

    it is not the only safe way but that would be fine......
  13. chefrob

    chefrob Master of the Pit OTBS Member

    140 would be fine, however chances are you will be passing through the danger zone in 4 hrs if your smoker temps are around 250 so you can probe them if you want in the beginning but be prepared to make sure you get it through if you do.
  14. bearcarver

    bearcarver Smoking Guru OTBS Member

  15. This is all good info . But I want to cast a stone if I may.  Here are my hang times for deer, I have cut the time down a little to be on the safe side .  My thoughts are you cannot have meat go bad without a contaminant which would only be on the outside . so 40 in the center is mute unless you stuck a probe in it.

    I usually follow these guidelines and never had a problem

    65-70 degrees--24-36 hours
    50    degrees--3-4 days
    35-40 degrees--7-10 days

    All depends on the humidity,if it's humid I go by the first if dry then the second.

    I don't remember where I got this scale from but it was years ago and I do remember shaving off some time when I copied it to be on the safe side.
  16. pignit

    pignit Master of the Pit OTBS Member SMF Premier Member

    If meat has been compromised you fall into the 160 degree internal rule. If it's been marinated, temp probed from cold, tenderized or compromised in any way it should be brought to an internal of 160 degrees. That means if you stick your temp prob in a nice juicy beef roast from the get go, forget eating it rare. It has to be brought up to 160 degrees. I know the rule has changed a degree or two but I go by 160 which means I will take it to at least 155 then let it rest. If you don't compromise the meat then you don't have to reach an internal of 160. I don't worry about the 40 to 140 in 4 because I always smoke at 225 - 250 and if you leave it alone, you'll be well within that range. I use to temp probe at the beginning, but I rarely temp probe at all any more. I know when to start checking it for being done so I don't start checking the internal until almost finished. If your running your smoker 225 to 250 your gonna hit an internal in 4 hours. You have to remember... even with a larger piece of meat... it will take it a little while to even get to 40 if it's been refridgerated.

    I can't really comment on the deer hang time... but if you hit it with a bullet or an arrow to kill it, you've introduced bacteria. I'll have to ask a couple hunting friends of mine about that one. A deer hanging dead for 36 hours in 70 degree weather doesn't sound appealing to me, but..... like I said. I'm not a hunter so I wouldn't know. I know I wouldn't eat a fish that had been dead that long without ice.
  17. tyotrain

    tyotrain Master of the Pit

    So how do you no what the temp is? say you want med. rare how do you no if u don't prob it?
  18. bearcarver

    bearcarver Smoking Guru OTBS Member

  19. pignit

    pignit Master of the Pit OTBS Member SMF Premier Member

    You probe it well into the smoke so that the outside temp of the meat has reached a temp that has killed the bacteria so that when you probe it you aren't introducing the outside to the inside.  


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