Kill Temps: Pork & Trichinella

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K Kruger

Senior Cook
Joined
Jan 10, 2005
Messages
326
Location
Okeechobee, Fla
(AKA trichina or trichinae)

A couple or three decades ago when many of us in the restaurant biz became aware of the possibility for lower finish internals in pork, 137F became the new number. As commercial pork had been getting increasingly (and unfortunately) leaner over the years, many chefs had all but abandoned bothering with simply preparing loins and tenderloins, instead using more labor- or time-intensive approaches (like marinades) in an effort to maintain moisture. Lower finish internals (which emanated from research but with little further details) were adopted wholesale, and many chefs I knew at the time re-introduced or introduced menu items they'd pretty much given up on--I know I did.

Several weeks ago, while in a discussion about pork, game meats, Trich and Salmonella, it arose that the kill point for Trich, a parisitic worm, is just as much a time @ temp issue as exists for the bacteria that cause food-borne illnesses. (Duh! Of course! I felt like such an idiot.)

In other words, once a particular temp is reached it becomes a matter of time at that temp for the kill step to be completed. Higher temps require shorter times and the times become shorter still as temps increase, till such a temp when the time is so short as to be considered 'instant'. (This is the same for bacteria. See here and here for time/temp info for meats and poultry.)

A gentleman involved in the discussion pointed us to the Code of Federal Regulations (specifically, 9CFR318.10, pp 244-256, revised in January of last year) that includes a time @ temp chart. It is based on the research of Tony Kotula, et al., from the 80s. Here:


Minimum Internal Temp


F ...... C ...... Minimum Time
________________________________

120 ... 49 ... 21 hours

122 ... 50 ... 9.5 hours

124 ... 51.1 ... 4.5 hours

126 ... 52.2 ... 2 hours

128 ... 53.4 ... 1 hour

130 ... 54.5 ... 30 min

132 ... 55.6 ... 15 min

134 ... 56.7 ... 6 min

136 ... 57.8 ... 3 min

138 ... 58.9 ... 2 min

140 ... 60 ... 1 min

142 ... 61.1 ... 1 min

144 ... 62.2 ... Instant

******************************

You'll note there is no 137 (which would come in around 2.3 min). I'm guessing that back then 137 was selected because that was the lowest temp that, when considering the probable time factor (the amount of time between hitting 137 and actually cutting the meat) coupled with the natural increase in internal temp that occurs during this rest, more than amounted to the just over 2 minutes necessary.

I'll reiterate: The instances of Trich in commercial pork are vanishingly rare but should not be assumed to be non-existant. Also: Bimetal analog therms should NOT be used for food safety purposes in thin items. Use a thermocouple or thermistor digital. (I don't use them for items of any thickness. Up to you.) Also: The chart above is for use with commercial pork, not wild game meats. They are susceptible to strains of Trich which are more temp resistant.
 
Good info. Now tell us when the Lysteria and E Coli bugs die and the subtle nuances of botulism? Thanks.

bigwheel
 
ok... so then I have a question.... taking into account this information from one of your links....

Temp Reached/Minimum Time for Chicken/Min Time for Turkey

140/ 35 Min / 33.7 Min
145/ 13 Min / 13.8 Min
150/ 4.2 Min/ 4.9 Min
155/ 54.4 Secs/ 1.3 Min
160/ 16.9 Secs/ 26.9 Secs
165/ <10 Secs/ <10 Secs

If you were doing a turkey... or chicken pieces... or whatever... and it took loonger than 35 minutes for your temp to climb from 140 to 150 would you really need to go any higher?

or...

lets just say you hit 150 with a bunch of chicken... pulled it off and dumped it in a pan together and held it for 14 minutes before serving... before serving.. you checked it and it had not gone down below 145... is it safe.

with all that being said... why do we take our chicken/turkey to 165? or for that matter... why not just 160... i know it normally takes me more than 27 seconds till i get to eat it...

just askin... is all
 
Gary in VA said:
ok... so then I have a question.... taking into account this information from one of your links....

with all that being said... why do we take our chicken/turkey to 165? or for that matter... why not just 160... i know it normally takes me more than 27 seconds till i get to eat it...

just askin... is all

Because you are looking to cook the meat not just kill the bugs. I take Turkey and chicken to 175 in the thigh or 165 F in the breast, by doing so I can be pretty sure that the bird is cooked fully all the way through.

If you cooked a chicken to 160 in the breast, it may be cooked right through, but if you were taking it as 160 in the thigh, there would still be pink uncooked meat on the bird.

The main point is you will eat them cooked the way you like them, there is some carry over cooking going to take place at any temperature, but if you like your meat under cooked, you will be happy to eat it at a lower finished temperature, if you want it more fully cooked then the finished temperature needs to go up.
 
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Precisely.

Cooking to pasteurize and cooking for palatbility are not necessarily the same.

I cook chicken breasts to 158-160. And I cook whole chickens and turkeys to that point as well (depending on how I am cooking them, sometimes I'll ice the breasts of whole birds before cooking so that the breasts take longer, leaving more time for the thighs/legs to get to higher temps).

Though you can cook thighs, say, to a lower safe temp than the usual 170-180 that most cooks use, at lower temps, say 160, most people would find the meat unpalatable--though it would be safe.

If you were doing a turkey... or chicken pieces... or whatever... and it took loonger than 35 minutes for your temp to climb from 140 to 150 would you really need to go any higher?
Not for safety you wouldn't.

lets just say you hit 150 with a bunch of chicken... pulled it off and dumped it in a pan together and held it for 14 minutes before serving... before serving.. you checked it and it had not gone down below 145... is it safe.
Yes. Whether you'd find it palatable is another question. You well might, especially if you were able to hold longer.

When one cooks sous vide, a technique that involves vac-packing foods then cooking in a constant-temp water bath, one often cooks at the actual finish temp desired. Cooking is often quite lengthy though, as not only is time required to bring the meat (or whatever) up to the temp of the water bath, additional time is needed for food safety, and additional time still is needed to cook the food--i.e., get the food to the point where it is tender, where, in the case of tough meats, enough time has elapsed for connective tissue breakdown to occur. At these low finish temps this takes quite a while. Tough cuts like short ribs are often cooked more than 30 hours.
 
K Kruger said:
.

.

Precisely.

Cooking to pasteurize and cooking for palatbility are not necessarily the same.

I cook chicken breasts to 158-160. And I cook whole chickens and turkeys to that point as well (depending on how I am cooking them, sometimes I'll ice the breasts of whole birds before cooking so that the breasts take longer, leaving more time for the thighs/legs to get to higher temps).

Though you can cook thighs, say, to a lower safe temp than the usual 170-180 that most cooks use, at lower temps, say 160, most people would find the meat unpalatable--though it would be safe.

If you were doing a turkey... or chicken pieces... or whatever... and it took loonger than 35 minutes for your temp to climb from 140 to 150 would you really need to go any higher?
Not for safety you wouldn't.

[quote:v93g553y]lets just say you hit 150 with a bunch of chicken... pulled it off and dumped it in a pan together and held it for 14 minutes before serving... before serving.. you checked it and it had not gone down below 145... is it safe.
Yes. Whether you'd find it palatable is another question. You well might, especially if you were able to hold longer.

When one cooks sous vide, a technique that involves vac-packing foods then cooking in a constant-temp water bath, one often cooks at the actual finish temp desired. Cooking is often quite lengthy though, as not only is time required to bring the meat (or whatever) up to the temp of the water bath, additional time is needed for food safety, and additional time still is needed to cook the food--i.e., get the food to the point where it is tender, where, in the case of tough meats, enough time has elapsed for connective tissue breakdown to occur. At these low finish temps this takes quite a while. Tough cuts like short ribs are often cooked more than 30 hours.[/quote:v93g553y]

I agree that poultry should be done (palatable).. and not "rare" so to speak... even if all the bugs are dead. I was just making "for instance" statements as to food safety to see if you agreed with what I was saying regarding food safety. I do not like "rare" poultry either, but I certainly don't like dry poultry.

the problem I have faced continually is when smoking chicken you get that red near the bone thing going on and of course.. people say "its not done" and I have to tell them that's what they get with smoked chicken and I assure them that it is done because I have temped nearly every piece that comes off the cooker and it is at least 165.. but you still get "that Look"... but then they will also complain if it is dry... so what to do....
 
Think the best advice would involve leaving chicken off the menu if you in catering or run a bbq bizness. As the fella splained it to me all it takes is some old bluehair to spot a redstreak in there and start yelling "raw chicken" then nobody else will eat it either.

bigwheel
 
That's why many commercial places do chicken quarters (leg/thigh combos) only. One can cook them to death and they're usually fine.

I've done numerous chicken breast jobs. I cook them to a low internal and hold for some time. Keppes them moist, still tender, and no pink. It is actually easier to do (usually) as a private chef or caterer than in most small commercial establishments.
 
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