Wednesday, April 28, 2010

Low-Temperature Sous Vide Chicken Breast

Chicken must be cooked to 165 or else it can harbor salmonella, right? WRONG. I found this to be interesting as well! In a post on Kenji Alt's column on Serious Eats, I was introduced to the concept of cooking chicken to a temperature of less than 165 (i.e. well-done) in order to preserve moisture and improve flavor. Sound familiar? Sound like something that we do with steak all the time? Yep!

So, here's the low-down: Killing bacteria in chicken is not simply a function of temperature reached, but also the time spent at that temperature. Here is a graph based on data found here that shows the amount of time that chicken (10% fat, worst-case scenario) must spend at a given temperature to achieve a 7-log(10) lethality of any salmonella present. In other words, by USDA's standards, it's clean.



You'll notice that the time necessary at 165 degrees is next to zero. This is the recommended done temperature for chicken because it's easy to achieve. The way you use this graph is first look at the desired temperature (on the left axis), follow the horizontal line toward the right until you hit the red curve, and then trace a line downward from that point on the curve to find the minimum hold time at that temperature. Want to play it safe? Don't get it hotter, just hold it longer! The meat will get a bit more tender as a result, but won't get any dryer. DISCLAIMER TIME: Cook chicken at a temperature lower than 165 at your own risk! I've given the link to USDA's data, and that is what you should refer to. My graph is simply a visual aid!

Alright... let's try some "not quite done, but perfectly safe-to-eat" chicken!

We'll be cooking this chicken with the sous vide method. If you're hearing this term for the first time, please read my other posts on the subject as well as the pages I link to. Although Kenji Alt cooked his to 140, I'm gonna go for 150, which should be nice and juicy without being medium rare. I'm not as hardcore as he is. ;-) The plan is to cook the chicken to the desired doneness in the crock pot, then sear the chicken in a hot pan of olive oil.

First off, I've found a nice new way to cook sous vide, other than the expensive option or the do-it-yourself method. It's not foolproof, but it's pretty good.

My buddy Scott Derham turned me on to a really nice crock pot that he has, made by Hamilton Beach, which is sold at Wal-Mart for less than $50. It includes a temperature probe for heating food to a programmable temperature. When used in the proper mode, the crock pot can heat up quickly to whatever temperature you set, and then it goes into "warm" mode where it will more or less hold temperature over time. It's meant to control cooking based on the internal temperature of a roast, chicken, etc., but when you fill the crock pot with water and just put the probe into that water, you have a temperature-controlled water bath. It works well, as long as you don't want to go lower than 140, because that's the minimum temperature setpoint. Here it is:



At the point when it reaches target temperature and goes into "warm" mode, it's really not reading temperature anymore, but is actually just heating at a constant power level. I've found that, with about half a crock full of water, it'll maintain about 137 degrees with no lid and 162 degrees with the lid on (while in a ~72 degree room). I had the lid on so that one side was latched down and the other side had about a 1/4" gap under the gasket, and it maintained 150.

I cooked four fresh chicken breasts seasoned with dried thyme, garlic powder and kosher salt. I seasoned the meat before putting it in the bag, which I've found re-constitutes dried herbs and spices. Desired? Sure, why not?



Once the chicken is in the bag, it's lowered into the water with the zipper open. I pushed on the bag with a plastic spoon to force the air pockets out and to make sure the chicken was laying in the bag in a single layer. Once the weight of the water has pushed all of the significant air pockets out of the bag, it might as well be vacuum sealed (but a lot cheaper!) I then zipped the bag up and folded it over inside the crock pot.


By the time I put the chicken into the crock pot it was at about 135, because I had started it up before I washed, trimmed and seasoned the chicken. I left it in there for 2 hours, even though I'm pretty sure it only took about 45 minutes or so for the chicken to reach temperature. According to my graph, it only needs to spend 3 minutes at 150, so I think this is PLENTY of overkill to play it safe. To keep the temperature regulated, I just adjusted the amount of gap between the lid and the crock on the left side. Pretty straightforward!

2 hours later, and we have some pretty ugly chicken! Notice the reconstituted herbs and spices. Yes, that's right, I turned back thyme. Sorry... that was really bad. Anyway, here are the pics:





We need to add some flavor and color to these plain-looking pieces of chicken. I got a 10" skillet with ~1 tbsp of olive oil smokin' hot and put some color on 'em, making sure to cook as hot as I could in order to minimize time on the heat and any further cooking of the fillet. The thyme and garlic caramelized/charred a bit, which added some additional flavor.

As you can see, this chicken turned out so moist! The texture was smooth, and you could almost chew it with your tongue!







I'll definitely be doing this again!

I also did a tri-tip a few days ago in this crock pot, and it turned out very well too. I just didn't take any pictures. The vacuum-sealed tri-tips from Costco can simply be tossed directly into the water and cooked in the package, then removed and pan-seared or grilled to get some extra flavor. Worked out very well!

I've ordered the parts to build my own sous vide temperature-controlled water bath, so keep an eye out in a couple weeks for my first runs with this setup. Also coming up is a writeup on the construction of my Ugly Drum Smoker (UDS).

5 comments:

  1. This idea of time vs. temperature applies to most anything. Pork is the same. I think the USDA says to get it up to something like 175F internal temperature to kill off trichinella, especially when dealing with wild pork.

    I found though that you can take it as low as 145-150F, and just increase your cooking time (i.e. in a slow cooker). The food really does come out better.

    The same myth applies when it comes to boiling water for purification. OK, boil it. For how long? The information out there ranges far and wide, but the reality is that if you get water to a boil, turn it off, you're done.

    Although I can understand people wanting to be cautious (after all, cholera, crypto and giardia are nasty-nasty), I really think this concept of "cook it to death" is borne of our germ-phobic society.

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  2. I think that for the masses, it's good to just tell people "get that chicken to 165!" so it's foolproof. I had never thought about the fact that there's a time-temperature relationship to killing bacteria in food, so this was a revelation to me. For those of us who like to make good food rather than just something to keep our bodies nourished, this is a great way to improve the safety AND the quality of the meat we prepare.

    Hmm... Now I want to do a pork loin roast. ;-) Marinate it, toss it on the smoker for ~1/2 hour to get some flavor into it, cook it sous vide to 150 or so, then sear it on the grill. Sounds awesome!

    I haven't done nearly enough research on recipes using this method, but will be doing some in the near future!

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  3. Hi Rodney,

    I found your blog by searching "sous vide tri-tip". I just made the most incredible tri-tip I've ever had by using a 130ish water bath and I wanted to see who else has cooked tri-tip this way. Anyway, I see that you've got the temperature controlled crock pot, have you had good luck with that setup? For a water bath, I use a deep fryer that I bought at a drugstore for about $20. It had a very large range on the temperature dial between the lowest frying temp an "off" and I spent some time trying to calibrate it and mark out what those temps were (it's not perfect, but for $20 it's pretty good).

    I think I'm going to try the Seattle Food Geek's instructions for the $75 water bath controller http://seattlefoodgeek.com/2010/02/diy-sous-vide-heating-immersion-circulator-for-about-75/ maybe modified to power a standard plug rather than fussing with those hot water heater elements.

    Anyway I'm still reeling from the tri-tip. I've cooked a few different cuts of beef this way and I think tri-tip might be just about perfect and it's super cheap where I live.

    I'm going to try chicken breast the way you wrote it up in this post. So far, chicken hasn't worked out for me (it always comes out bloody and raw tasting), but I've never tried boneless chicken breasts.

    Thanks for blogging this, I always mean to do that but I end up eating the results before there is a chance to take pictures :).

    Peace,
    Josh

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  4. Hey Josh-

    Ya know, I've tried sous vide tri-tip, and haven't noticed any advantage to cooking it this way, at least as far as only leaving it in the water long enough to heat through to the desired temperature. I'm not sure if leaving it in there for a few hours would make it more tender or not. My favorite way to cook tri-tip is to sear it over extremely hot coals and then indirectly cook it in my charcoal grill at 300-350 with oak or manzanita smoke until it's at 135 internal. Let it rest for 30 minutes or so wrapped in foil in a small ice chest, slice it super thin, then pour the juices over the top of the slices. It turns out great! Plus, with this method you can get some smoke into the meat, which I *really* like on tri-tip. Hmm... I think I'm gonna have to deviate from the gadgetry and just post about BBQ'ing some tri-tip. Thanks for the motivation! ;-)

    As for that crock pot, I've given up on it. It responds SO slowly! I've since built a temperature controller very similar to the one I mentioned on another post on this blog, and use a small rice cooker to cook in. The rice cooker responds VERY quickly and the temp is rock solid once it gets up there. I'd recommend doing this over building that $75 system. I started to build that one, but realized about halfway through getting all of the parts that it'd never be a $75 system. ;-) The controller I built cost me $85 in parts, and the rice cooker was only about $18 back when I bought it. Plus, it's also a rice cooker/vegetable steamer when it's not on sous vide duty, so it's worth the extra expense!

    Here's a drawing I did of the controller I built:

    http://www.creativesparkeng.com/misc/SousVideController.pdf
    All of the part numbers are in the parts list on the right. The end plates require some creative carving in order to get the tangs on the power inlet/outlet housings to lock in, since those tangs are made for a thinner end plate than this enclosure has... That's the only reason I didn't publish a how-to on building this thing. However, if a person was to just get a 3-prong extension cable and butcher it so the power could be passed in and out of the enclosure through a couple of ~5/16" round holes or strain relief grommets, it'd be relatively easy to build! Maybe I'll do one like that and publish a how-to. It's been great to use so far!

    Not shown in the drawing is the temperature probe I wired up to the connector:
    http://www.auberins.com/index.php?main_page=product_info&cPath=15&products_id=46

    Here's a video of me using it on some ribeye steaks:
    http://www.youtube.com/watch?v=WQD3os7OVIs

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  5. Josh, there are a couple new posts you'll likely be interested in. ;-)

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