Monday, March 22, 2010

Never underestimate residual heat

If you've ever taken a class with me, you probably heard me lament that the default protein most Americans cook for dinner is a skinless boneless chicken breast. So you probably never expected me to be writing about chicken breasts. I didn't either. I never expected to want to cook them, write about them, or teach people how to make them, until three things happened:
  • I've tried Zuni cafe recipe for roast chicken
  • I realized that legs and breasts can't be cooked together (if you want perfection)
  • I stopped listening to FDA about the "safe" temperature of chicken
I stewed in those three thoughts for about a year, cooked 50 or so chickens, and what do you know -- you can indeed make chicken breasts that are as lovely as a pan roasted fillet of fish or a medium-rare rib-eye.

I can't say that Zuni cafe chicken is amazing, but it has potential. Roasting in a skillet helps the skin crisp and leaves you with wonderful brown bits for the sauce, and high heat on a small chicken works surprisingly well. Salting at least a day in advance is a fabulous idea too. The chicken becomes more succulent, flavorful, and tender. If you are cooking a whole chicken, that is a great method, but you have no idea how much better it can be if you cook the legs and breasts separately.

The legs taste best when they are cooked to 200F before being removed off the heat (that's when all the connective tissue melts); the breasts taste best around 150F (taking residual heat into account, they need to be taken off the heat way before they reach 150F). Unfortunately, that's impossible to accomplish on a whole chicken. But if you break it up, you don't need to compromise with 160 breasts / 170 legs.

I am sure some of you are getting nervous even at the mention of 150F for chicken. Wait till I tell you to take it off the heat at 130F :) I used to take it off the heat at 140F, expecting the temperature to rise 10 degrees, but this weekend I put this theory to the test. I got the breasts out of the oven at 130F and left the thermometer in the center of the roast. During the next 15 minutes, the temperature went up by 26 degrees to 156F. My roast was 1 Lb 10 oz (the roast was 1 Lb 9 oz, plus an ounce of stuffing). Then my wonderful assistant Janet, agreed to perform the same experiment at home. Her roast was a bit smaller and not stuffed, weighing in at 1 Lb 5 oz. The temp went up by 21 degrees. So, never underestimate residual heat.

150F? Is that medium-rare chicken? No -- it's completely opaque and "normal" looking, just more tender and juicy than you are used to. Is it safe? I don't know what FDA would have to say about it, but here are salmonella facts that I was able to find. Salmonella dies if held at 131F for 1 hour, 140F for 30 minutes, 150F for 10 minutes, and 160 for 2 minutes. In other words, if you want officially safe chicken, cook it to 140F, and let it rest for 15 minutes. You'll get your 160F.

I do find that it tastes a lot better at 150F and I am willing to eat it, FDA be damned. First of all, bacteria don't go from super healthy to dead in a split second. If 150F for 10 minutes would kill them, 150F for even 5 minutes would weaken them and make the odds of them infecting you a lot lower. Also, keep in mind that duck breasts are routinely served at 130F. So is foie gras. That's still poultry and can have salmonella just like chicken.

What temperature you cook your chicken to is completely up to you. I just wanted to explain that taking breasts off the heat at 160F is an overkill safety-wise and a guarantee of dryness.

Instead of rewriting the recipe here again, I've updated my previous post with a few more details.

11 comments:

Daniel said...

Just a nitpick from a food microbiology standpoint...a incomplete kill step does not weaken the bacteria, it actually makes them stronger. It puts them into a "survival mode" which forces some changes in the cell to make it more resistant to heat, acid, low water activity, etc. Given that, whole birds you break down yourself are by far your safest bet, as cross contamination for several animals is minimized with minimal handling.

Helen said...

Hi Daniel,

I've been looking for more info on bacteria growth. Would you mind giving me a link to the information you mentioned? Also, I found several sources (including the Joy of Cooking) that indicate that eggs are safe if cooked to 140F. FDA has recently started recommending that they should be cooked higher, but if we lived with 140 for so many years, it's probably not all that unsafe. Why is it 140 for eggs and 160 for chicken? Is salmonella in chicken different than salmonella in eggs? I've been dying to talk to a biologist specializing in bacteria about this for a long time. If you are such a person or know anyone who can help, drop me a line.

Thanks!
-Helen

Anonymous said...

Hi Helen,
This is a fascinating discussion and, once again, I think you have got it spot on.

Another chef who has reached a very similar conclusion to you is Peter Hertzmann. He has published a wonderful little article called "Le livret de température des viandes" on his website. In case you haven't seen this, here is a link to it.

http://www.hertzmann.com/articles/2002/cook/book_E5.php?link=2002-11-X

Keep up the good work.

Peter

Anonymous said...

Hello there - Avid fan for a long, long time. Can you give us some thoughts on cooking time for minced chicken and turkey? Is it true that once can eat the meat as soon as it turns opaque (assuming that one does not have a kitchen thermometer). How would you determine cooking time by look and feel rather than thermometers e.g while cooking a sauce that uses minced chicken or turkey? Thanks much in advance. JH

Helen said...

Hi Peter,

Thanks so much for the link to Hertzmann's article. Wonderful resource!

JH: I almost never work with ground chicken or turkey, so I am not off much help here. Ground meats are generally a lot more dangerous than whole. In other words, eating a medium rare burger is a bigger risk than medium rare steak. I am not a biologist, but here is how I understand it. Bacteria needs oxygen to grow, so most of it is on the outside of the meat and that gets cooked to very high temp in a steak. In a burger however, some of it could end up inside after grinding and unless you cook it through, you are taking a risk. That being said, I eat medium-rare beef burgers all the time. But I eat a lot of things that other people wouldn't find risk worthy.

As far as telling by look... Not sure what exactly you are cooking with your ground poultry. If it's something solid, like a meatloaf or a burger, you really need to use a thermometer. If you don't have one, go to Target, spend $15 and get yourself one (I strongly suggest digital). It's probably the best $15 you'll spend on your kitchen.

Cheers,
-Helen

Ed Schenk said...

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Congrats!

agoodic said...

Just a nitpick from a food microbiology standpoint...a incomplete kill step does not weaken the bacteria, it actually makes them stronger. It puts them into a "survival mode" which forces some changes in the cell to make it more resistant to heat, acid, low water activity, etc. Given that, whole birds you break down yourself are by far your safest bet, as cross contamination for several animals is minimized with minimal handling.

p

Tanya said...

I love this post and I am 100% with you on those three points. I hated chicken until those three, plus this one: use boneless skinless chicken thighs for breastmeat any day for much improved texture and flavor that justifies the added fat.

Brett Sutcliffe said...

Wow your chicken dishes always have good presentation. Looks so juicy not dry at all.

Matthew: said...

The inside of a chicken breast is almost impossible to contaminate with salmonella. One would have to pierce the breast with something sharp, which would carry the bacteria into the piece of meat. This isn't impossible, but is unlikely unless you prod the meat before cooking it. Once the outside is heated to over 160F, which should happen long before the inside is at that temperature, the risk of food poisoning is essentially zero. (The same thing is true with all meat, which is why an undercooked steak won't send you to the hospital later that same night.) There are other possible infections, however, either from parasites or, as you mentioned, ground meats. Sous-vide is obviously a different beast.

Also, you get a lot of comments on this blog. I was wondering if you'd often seen the sort of trolling that Daniel and agoodic seem to have engaged in?

HVAC Man said...

I think Americans are the best cook in cooking chicken. We need to learn a lot from them.Can you give the link you have mentioned.