Slow Cooking, Barbecue, and the Danger Zone
So I have always been told mixed things about the safety of slow cooking meat. I've heard food experts say that as long as meat is cooked to a safe internal temperature, it is safe to eat. Fair enough. But last Thanksgiving had the inclination to pursue the most perfectly tender turkey ever-- perhaps, I thought, by slow cooking it at 200 degrees overnight. After consulting the FDA guidelines and various forums online, I learned that the "safest temperature to cook a turkey is 325 degrees." Supposedly, if the bird lingers in the "danger zone", around 140 degrees internally, it will become a breeding ground for bacteria that will produce a cocktail of deadly toxins. These guidelines claim that no amount of cooking will be able to remove these toxins after they have already been produced, and as such, they will surely kill me. What?
Now, I want to make something clear: I am an avid slow-smoked barbecue enthusiast. Barbecuers, and even barbecue restaurants beholden to health code, will do things like smoke a brisket at 200 degrees for 18 hours. I once carefully eyed pitmaster Tootsie's thermometers at Snow's in Lexington, Texas, and she went no higher than 210 in any of her smokers, which had all been going since 3AM the previous morning. Given such a low cooking temperature, one would imagine that virtually every meat would linger in the "danger zone" for hours on end, producing enough toxins to kill me several times over. Then, I thought, maybe these health specialists are only referring to poultry due to the salmonella risk. But the SAME FDA that cautioned me against slow-roasting turkey suggested that I am allowed to smoke my chicken at 250 degrees for many hours.
So finally, I thought to myself, maybe the smoke retards the growth of bacteria to an extent that it is somewhat cured during the process, akin to smoking salmon. Then I remembered all of the traditional Old World and Americans recipes I have encountered in my life that have called for slow-roasting birds for outrageous amounts of time without any smoke at all. Then there's the crockpot. I'm sure many of you are familiar with, and have probably made crockpot recipes that ask you to skirt with the danger zone for many hours. All orders of slow-cooking have been practiced across cultures for centuries, long before modern-medicine. Maybe I'm naive, but I think that were it so dangerous, people would have gotten ill, died, or otherwise decided that it was a bad idea.
Does anyone have the final scientific lowdown on all this? I'm not going to stop slow-cooking meat, but I'd still like to know.
Most of the potential bacterial contamination is from surface contact (unwashed hands, prep surfaces, utensils, etc). It starts on the outside and moves inward.
The surface of whole cuts/birds reaches the cooking temp fairly quickly, so the contamination (if any exists) would not have a chance to grow during the cooking process.
Ground meats are different in that any potential contamination present has been mixed throughout the meat.
Cooked foods that are cooled and reheated have the potential to become contaminated if they are left in the "danger zone" for extended periods.
hannaone is correct. Muscle tissue is basically sterile. The action is inside the cavity and exterior parts of the bird that has come into contact with bacteria either through internal or external contamination. The federal guidelines are there to keep people safe that stuff their birds and then cook low and slow. The heat will kill the surface bacteria and as long as you keep the cavity of the bird open to the hot air (nothing inside the cavity), you are good to go.
I think slow roasting an unstuffed turkey at 200* overnight would result in an internal temp of at least 140* for a detrimental length of time. Ideally, start your turkey in a 400* oven, which will kill surface bacteria, then lower your oven temp if you desire. You have consider the weight of the turkey and how fast the internal temperature will rise past 160*. The deal is to get the food product temperature up to 160* or down below 40* as quickly as possible. Remember, turkeys and chickens are different weights; slow roasting a 20# turkey at 200* and smoking a 6# chicken at 250* will result in reaching internal temperatures at different rates of time, to say nothing of the 50* temperature difference in processing. The longer time a food product spends in the danger zone (40*-140*) the more likely for bacterical growth. Poultry held (held, not cooked to an internal temp) at anything over 140* is considered in the "safe" handling zone, although hot foods should be held at at least 160*. I roasted my turkey at 325* this year with no noticeable dryness. Employing other moisture- and flavor-capturing methods, like brining, are a better way to a tender, juicy bird. Safer, too.
Salmonella bacteria dies after being exposed to 150* for a half hour. E Coli is unique in that it is slightly more heat resistant than other eneteric bacteria, and needs to be heated to 160*. Although aproximately 150,000 people suffer from salmonella poisoning every year, very few die.
Most newer slow cookers are set to 200* for low and 300* for high. Check your model's stats.
Smoking food causes toxic inhibition of bacteria, when combined with heat, denatures bacteria. A number of wood smoke compounds act as preservatives. Phenol and other phenolic compounds in wood smoke are both antioxidants, which slow rancidification of animal fats, and antimicrobials, which slow bacterial growth. Smoke is an antimicrobial and an antioxidant. Other antimicrobials in wood smoke include formaldehyde, acetic acid, and other organic acids, which give wood smoke a low pH—about 2.5. Smoking, combined with salt curing, is an acceptable method of preserving food.
Long-smoking at 250* is considered a safe handling temperature and practice. I'm sure the pitmaster was using a thermometer to check internal temp of her product.
A final scientific breakdown?? No! However, IMO BBQing a turkey over night at 200* would result in an over cooked bird...dried out breast etc. ~~~~ I routinely BBQ meats (ribs, butts, briskets, shoulders, chucks, etc) somewhere + or - 212* ~~~~ For turkeys I start with a small bird (15lbs or less) remove it from refrigeration an hour or so prior to taking it to the fire, preheat my pit to 250* and BBQ the bird until it reaches an internal temperature somewhere around 155*... Carry over will take it above 160* which is safe to eat. ~~~ How long is it in the "danger zone" internally? I don't know. I've never concerned myself with the fact. ~~~ IMO the greatest danger comes from the surface temperature, and in a 250* pit it will rise above 140* fairly quickly. ~~~ Larger birds can be "butterflied" with the same results. HTH
Have Fun and Enjoy!!
Im with Uncle Bob, and based on years of experience. We do turkeys and chickens all the time, and Im getting my heat to around 220-225 then putting the top down and let her rip. After you do a few you get a feel for time vs weight of the bird--though you have to watch near the approximated end time as each bird seems to have a life of its own for reaching internal done temp. But bottom, we have never died from doing this, and I was taught by a long line of bbq smokers how to do this.