Duck Confit

[Dave the Cook]

I think we're simply dealing with this: poach a chicken breast with aromatics in a water-tight container at 135F.

So, to come back to my original concern:

I believe you when you say that you've never made anyone sick. I think that is a testament to your skill -- and your luck. I'm not sure I'd want to give it to my kids.

And I'm still wondering about the texture. Anybody know at what temperature chicken breast protein coagulates?

[inventolux]

When you cryovac, you remove a lot of air. Thats less air to heat up and expand. When you simply wrap things in plastic wrap, you trap in more air and are heating up a larger air mass. Like a hot air balloon.

Wait? You're saying you do this in plastic wrap?! Dude, there's no way that builds up any pressure. And yes, I've done that before! I don't care how much string you tie around the package, there is no way any pressure builds up. I mean, how strong do you think the plastic wrap is? Does it not occur to you that any significant internal pressure would easily burst multiple layers of plastic wrap? For that matter, you could wrap the whole package in duct tape, and any significant internal pressure would burst that too.

(My apoligies if I am misunderstanding your technique and use of materials.)

Multiple layers of plastic wrap. (6) Then you tie it like a roast. It will build a lot of pressure depending of the temperature of the air that gets trapped inside the pouch. If you indeed have already done this experiment,(and I find that remarkable if you have already used this exact technique) then you would see my point.

And for Dave The Cook:

We would serve at least 100 of these things at charlies some nights and the same exact guidelines would be followed. Nobody would ever get sick, it has nothing to do with skill or luck. The texture of the chicken is gorgeous, and the color is non-translucent opaque white, the perfect texture for chicken. Its a texture of moist tenderness that isnt stringy or chewy. It brings the chicken to the point of necessary coagulation. Any more and the chicken is ruined.

Edited June 27, 2003 by inventolux (log)

[Dave the Cook]

Considering my "football example" above, the water on my scalp would be making a phase shift from a liquid to a gas state via sublimation.  And the temperature of that steam would be <100C/212F.

That's not sublimation, is it? Sublimation is solid to gas, bypassing the liquid phase.

[slkinsey]

And I'm still wondering about the texture. Anybody know at what temperature chicken breast protein coagulates?

I have done this with a significantly warmer water bath (say 150F) and finished the breasts under the broiler to crisp the skin. Even then, the texture was a little mushy and undercooked-seeming for that kind of bird (have done chicken and also guinea fowl). Now, on the other hand, darker-fleshed poultry (squab, etc.) might be okay cooked to a lower temperature. Chicken? No thanks.

One of McGee's books probably has the temperature for chicken protein.

[mcdowell]

Considering my "football example" above, the water on my scalp would be making a phase shift from a liquid to a gas state via sublimation.  And the temperature of that steam would be <100C/212F.

This is where we're breaking down, I think.

It doesn't make a "phase shift" from liquid to gas, it just looks like it did!!

What's really happening is that extremely tiny (2-20 micron) water droplets are binding with molecules in the air creating a haze. It's not any more "steam" than that cloud floating overhead (weather permitting).

[slkinsey]

Considering my "football example" above, the water on my scalp would be making a phase shift from a liquid to a gas state via sublimation.  And the temperature of that steam would be <100C/212F.

This is where we're breaking down, I think.

It doesn't make a "phase shift" from liquid to gas, it just looks like it did!!

What's really happening is that extremely tiny (2-20 micron) water droplets are binding with molecules in the air creating a haze. It's not any more "steam" than that cloud floating overhead (weather permitting).

Right. Sorry about that. Upon further thought, in this particular case it would be evaporation followed by condensation.

It still strikes me, however, that "steam" is nothing more than water gas in a visible form. I gather that there can be other understandings of this word in various fields, but I can't find any general purpose scientific definition that makes a temperature greater than 100C necessary.

Edited June 27, 2003 by slkinsey (log)

[Dave the Cook]

inventolux: Have you ever checked the internal temperature of the chicken breast during or immediately after cooking?

If it ever gets higher than 135F, 1) I'd be very surprised; 2) it would go a long way towrds convincing us skeptics. That would prove that you are obtaining elevated pressure.

I don't have McGee with me, but if memory serves, I think the coagulation temp is about 150 -- but you would need several minutes at that temperature to effect full coagulation. Below that, I'm with Sam -- ewww.

edit: for clarity

Edited June 27, 2003 by Dave the Cook (log)

[inventolux]

inventolux: Have you ever checked the internal temperature of the chicken breast during or immediately after cooking?

If it ever gets higher than 135F, 1) I'd be very surprised; 2) it would go a long way towrds convincing us skeptics. That would prove that you are obtaining elevated pressure.

I don't have McGee with me, but if memory serves, I think the coagulation temp is about 150 -- but you would need several minutes at that temperature to effect full coagulation. Below that, I'm with Sam -- ewww.

edit: for clarity

What if the chicken breast is 1/8 th of an inch thick? What temperature would you cook that to? Will you go to a 165f internal? If so, then you will have one dry as a bone bird.

Edited June 27, 2003 by inventolux (log)

[Dave the Cook]

inventolux: Have you ever checked the internal temperature of the chicken breast during or immediately after cooking?

If it ever gets higher than 135F, 1) I'd be very surprised; 2) it would go a long way towrds convincing us skeptics. That would prove that you are obtaining elevated pressure.

I don't have McGee with me, but if memory serves, I think the coagulation temp is about 150 -- but you would need several minutes at that temperature to effect full coagulation. Below that, I'm with Sam -- ewww.

edit: for clarity

What if the chicken breast is 1/8 th of an inch thick? What temperature would you cook that to? If you go to a 165f internal? If so, then you will have one dry as a bone bird.

Typically I cook chicken breast to 155, unless it's been brined. In that case,you can go a littlle higher.

But again, you're not answering my question.

[inventolux]

inventolux: Have you ever checked the internal temperature of the chicken breast during or immediately after cooking?

If it ever gets higher than 135F, 1) I'd be very surprised; 2) it would go a long way towrds convincing us skeptics. That would prove that you are obtaining elevated pressure.

I don't have McGee with me, but if memory serves, I think the coagulation temp is about 150 -- but you would need several minutes at that temperature to effect full coagulation. Below that, I'm with Sam -- ewww.

edit: for clarity

What if the chicken breast is 1/8 th of an inch thick? What temperature would you cook that to? If you go to a 165f internal? If so, then you will have one dry as a bone bird.

Typically I cook chicken breast to 155, unless it's been brined. In that case,you can go a littlle higher.

But again, you're not answering my question.

I guess you will have to either perform the exercise for yourself or wait to watch me do it.

[slkinsey]

Multiple layers of plastic wrap. (6) Then you tie it like a roast. It will build a lot of pressure depending of the temperature of the air that gets trapped inside the pouch. If you indeed have already done this experiment,(and I find that remarkable if you have already used this exact technique) then you would see my point.

I did it that way before I had the capability to cryovac. Didn't seem like rocket science to try doing it that way. I have also done it with heavy-duty ziplock bags with the air sucked out of them.

What I think you don't quite understand is that the expanding of the plastic from the air does not necessarily mean that there is significant pressure being built up inside the plastic. Take this example: Put piece of chicken inside a balloon. Blow the balloon up with air. The balloon expands. Do you think that the chicken inside the inflated balloon is under significantly greater pressure than it was under previously? This is to say, do you thinkthe air pressure inside the balloon is significantly greater than the air pressure outside the balloon? Hint: Google for Boyle's Law.

Edited June 27, 2003 by slkinsey (log)

[slkinsey]

But again, you're not answering my question.

I guess you will have to either perform the exercise for yourself or wait to watch me do it.

Inventolux, what I think people are having a problem with is that you are making a lot of claims that seem to fly in the face of science, and you refuse to offer any sound support whatsoever other than your own opinion and "you'll just have to wait to watch me do it." This kind of argument simply does not hold water.

[inventolux]

Multiple layers of plastic wrap. (6) Then you tie it like a roast. It will build a lot of pressure depending of the temperature of the air that gets trapped inside the pouch. If you indeed have already done this experiment,(and I find that remarkable if you have already used this exact technique) then you would see my point.

I did it that way before I had the capability to cryovac. Didn't seem like rocket science to try doing it that way. I have also done it with heavy-duty ziplock bags with the air sucked out of them.

What I think you don't quite understand is that the expanding of the plastic from the air does not necessarily mean that there is significant pressure being built up inside the plastic. Take this example: Put piece of chicken inside a balloon. Blow the balloon up with air. The balloon expands. Do you think that the chicken inside the inflated balloon is under significantly greater pressure than it was under previously? This is to say, do you thinkthe air pressure inside the balloon is significantly greater than the air pressure outside the balloon? Hint: Google for Boyle's Law.

Air inside a balloon and air inside a heated cavity are 2 totally different scenarios. You arent just using pressure, you are using heat over a longer period of time than you would normally use. The google search doesnt help my case or your case because it doesnt take into consideration of slowly heating the item inside the cavity, holding at a constant temperature for a period of time, then finally allowing it to rest for a period of time. If you were to try this zip lock bags, the bags would surely burst because the zipper seal isnt strong enough to hold the pressure. (I know because I have tried it to lower costs on bags which typically run higher than zip locks.)

[Dave the Cook]

Inventolux, what I think people are having a problem with is that you are making a lot of claims that seem to fly in the face of science, and you refuse to offer any sound support whatsoever other than your own opinion and "you'll just have to wait to watch me do it."  This kind of argument simply does not hold water.

I agree.

I am not absolutely conviced that the technique doesn't work, though I have my doubts. I know that Sandor Zombori uses this techique for rack of lamb, but lamb at 135F is quite different from chicken at 135F.

But if it does work, I am sure that we don't have a good explanation of why.

[inventolux]

I will be the first to say I am no chemist. I am just beginning to understand that side of food.

Edited June 27, 2003 by inventolux (log)

[Dave the Cook]

Take 1 chicken breast and season it with S&P

Place onto plastic wrap

Pour 6 tb buttermilk onto chix

Add 1 clove of crushed garlic, 1/2 diced shallot, 2 slices of lemon peel, and 2 sprigs of thyme

wrap up 4 to 6 times and tie with kitchen string like a roast

Poach at 135f for 25 to 30 minutes

Let rest for 5 minutes.

Perfectly cooked chicken

OK, I'm going to try this tonight.

inventolux, could you be a little more specific about the chicken? Bone-in whole breast? Boneless half breast?

When you say "tie...like a roast" do you mean roll the breast into a cylindrical shape as well?

Do the other ingredients get piled on top, wrapped inside, or distributed as evenly as possible?

Any tips on maintaining such a low temperature for half an hour? Double boiler?

[slkinsey]

Just to add another data point, I did the following calculation. My assumption was that the volume would not change at all (i.e., that the package would not bulge), which would not be the case in real practice.

Before heating

Volume 1: 1 liter

Temperature 1: 277 kelvin (39F)

Pressure 1: 1 atmosphere

After heating

Volume 2: 1 liter

Temperature 2: 330 kelvin (134F)

Calculated Pressure 2: 1.19 atmospheres

As we can see, the pressure increased by 19%.

For the calculations, I relied on The Combined Gas Law Calculator.

[Dave the Cook]

Just to add another data point, I did the following calculation.  My assumption was that the volume would not change at all (i.e., that the package would not bulge), which would not be the case in real practice.

Before heating

Volume 1: 1 liter

Temperature 1: 277 kelvin (39F)

Pressure 1: 1 atmosphere

After heating

Volume 2: 1 liter

Temperature 2: 330 kelvin (134F)

Calculated Pressure 2: 1.19 atmospheres

As we can see, the pressure increased by 19%.

For the calculations, I relied on The Combined Gas Law Calculator.

Thanks for that.

In other words, it's not significant, especially once you take the expansion of the plastic into account.

[inventolux]

Take 1 chicken breast and season it with S&P

Place onto plastic wrap

Pour 6 tb buttermilk onto chix

Add 1 clove of crushed garlic, 1/2 diced shallot, 2 slices of lemon peel, and 2 sprigs of thyme

wrap up 4 to 6 times and tie with kitchen string like a roast

Poach at 135f for 25 to 30 minutes

Let rest for 5 minutes.

Perfectly cooked chicken

OK, I'm going to try this tonight.

inventolux, could you be a little more specific about the chicken? Bone-in whole breast? Boneless half breast?

When you say "tie...like a roast" do you mean roll the breast into a cylindrical shape as well?

Do the other ingredients get piled on top, wrapped inside, or distributed as evenly as possible?

Any tips on maintaining such a low temperature for half an hour? Double boiler?

Lets get specific:

Take a boneless, skinless chicken breast and season it with salt and pepper, let the seasoning dissolve into the meat. (about 7 minutes)

Take 1 clove of crushed garlic, 1/2 of a minced shallot, 3 sprigs of fresh thyme, 6 tb of buttermilk and a couple of lemon peel slices, yellow part only (1/2 inch wide X 1 inch long) and place onto a piece of plasic wrap about 1 foot squared. Wrap up like a package.

Repeat the wrapping procedure 5 more times. This will depend on the quality of your plastic wrap, restaurant wrap is better.

Tie the pouch like this illustration and add one more tie the length of the breast. Make sure it is tight. If you would like to roll the breast then you will need a longer cooking time. If it is about an 8 ounce breast, about 35 minutes.

Poach in water that is just below steeping. Make sure the breast is firm to the touch, not translucent and is opaque. But most of all, make sure you frequently pull the pouch out of the water to shift the ingredients to maintain even flavoring and cooking.

The even heating takes practice unless you have a thermometer.

[Dave the Cook]

I cooked Inventolux's chicken last night, using four boneless breasts. Two were prepared according to Invento's techinique; two others were prepared according to slkinsey's allusion to ziplock bags - one was tied, one was not:

I used a 12-inch saute pan for poaching, and attached a probe thermometer to monitor the temperature of the water:

The breasts were poached for 35 minutes at about 145 F. I didn't have a flame tamer (for some reason, they've become scarce), so 140 was the lowest stable temperature I could manage. I let the temperature rise to about 150 before putting the chicken in the pan. The temperature dropped to about 130, then rebounded to 145 within a few minutes.

Despite careful preparation, enough air remained in the packages to make them slightly buoyant, so I used a steamer basket to keep them submerged:

The packages were massaged briefly and rotated every seven minutes. At the 35-minute mark, I removed the packages:

I quickly inserted a digital themometer into one each of the wrapped and bagged breasts. The wrapped breast had an internal temperature of 125F; the bagged breast was 139F. I let them rest for five minutes, then opened all the packages. I cut one each of the wrapped and bagged breasts in half (wrapped on left, bagged on right):

I finished off the wrapped breasts in an already-hot pan:

It took about three minutes to bring them to an acceptable point.

Comments and observations:

135F is not very hot. (As a basis for comparison, my tap water is at 113F.) I was able to massage and turn the packages with my bare hands without lingering discomfort.

Thirty-five minutes is not sufficient, at this temperature, to cook the chicken to an aesthetically acceptable point. Unfortunately, my camera did not focus on the meat in the photo above (it seems to have captured the tongs perfectly instead). But even in this flawed depiction, the glistening, uncooked flesh is apparent. I am not sure if 135F (which eventually the meat would have achieved in a 135F-water scenario, after perhaps 50 or 60 minutes) would be acceptable or not; the meat in the 139F breast was what I would consider just barely done. The flesh had just solidified; any less done and I wouldn't have dared serve it to unadventurous types (of which I had three last night). Even then, I was blessed by subdued lighting.

Given the wrapping and the tying, it is impossible to determine doneness with any accuracy. Indications of doneness (opacity and flexibility of meat) can only be guessed at -- it would be an educated guess, but a guess nevertheless. Continued experience with this technique would probably help.

The added flavor components (buttermilk, aromatics, lemon zest, etc.) adhered to the wrapped breasts very well. The bagged-tied showed a little of this phenomenon; the bagged only breasts did not at all. However, there was little discernable difference in taste of the meat. When finishing the meat off in the skillet, I did not remove the adhering components; this made for a fragile but tasty crust, mildly reminiscent of a tandoori-preparation.

No packages leaked. Whatever pressure might be developed inside a "sealed" container (I am now convinced that it is minimal) is not sufficient to rupture the closure of a ziplock bag (this was a "freezer-style" construction, which comprises slightly heavier plastic than the standard bag).

Comparing the finished temperature of the chicken packaged in different ways convinces me that proximity to heat source (the hot water) is far more significant than any pressure that might develop inside the package.

The wrapping (five layers of commercial-quality plastic) provided significant insulation. I don't doubt that addtional cooking time would have brought them to a condition similar to the bagged breasts. At 145F, anyway, I would call this a successful method, at least on techincal grounds.

The appeal of this technique for boneless chicken breasts eludes me. The result is (or could be, I am sure) a perfectly tender, perfectly cooked piece of chicken (with an interesting moist coating). But the preparation is a pain in the ass, and I already know how to cook this meat to this state with far less trouble. If I had a FoodSaver, I might soften this judgment somewhat.

However (and maybe we can turn this thread back to its original intent), I can see how much sense it makes for confit, especially if you have a FoodSaver, or some other way to create minimally-sized, liquid-tight pouches. Although I am still dubious of the temperature (for safety reasons), I don't see why this wouldn't be an acceptable, possibly superior, way to confit duck legs with a minimum of fat, at say 160F. But then, maybe we already knew that?

[Jinmyo]

It certainly is a good way to get around not having enough duck fat.

[paul o' vendange]

I will just throw this in. Likely the answer is no (esp. in light of slow braising/tight lids), but is it possible we don't want all the volatiles to remain in our cooking? I can only infer from brewing...where some compounds are not desired, and so some evaporation is desired (largely to rid of sulfurous, and vegetal compounds). I can't think of where this would apply in cooking, and obviously our job is largely to extract and preserve, not drive off, flavor and aroma. But I wonder if there is something here?

Merely a point of thought. Food chemists?

[JasonCampbell]

I'm probably being a bit thick, but isn't 135 F about 57 Centigrade?

Incidentally, if you're short on fat, top it up with goose fat.

[Dave the Cook]

...isn't 135 F about 57 Centigrade?

Yes. Why do you ask?

Edited June 28, 2003 by Dave the Cook (log)

[slkinsey]

Very, very, very cool of you to do this, Dave! And, of course, it is reassuring to see our predictions confirmed by your experiment.

However (and maybe we can turn this thread back to its original intent), I can see how much sense it makes for confit, especially if you have a FoodSaver, or some other way to create minimally-sized, liquid-tight pouches. Although I am still dubious of the temperature (for safety reasons), I don't see why this wouldn't be an acceptable, possibly superior, way to confit duck legs with a minimum of fat, at say 160F. But then, maybe we already knew that?

Other than making the confit technique possible with a much smaller amount of extra fat, I don't see how it offers much of an advantage over the regular way. Seems like more trouble really. And I would think that most people interested in making duck confit at home would be able to accumulate enough extra duck fat to make this technique superfluous with relatively little difficulty and a little forethought. I always cut out and render down the extra fat from poultry before roasting and save it in the freezer. My friends may think it's strange that I have 4 jars of fat in the freezer (goose, duck, chicken, bacon, lard) -- but maybe they're not real friends. I mean, I can always think of something to do with rendered animal fat.

Anyway... getting back on track... The one advantage doing it in cryovac/FoodSaver it does seem to offer is that each duck leg would be in its own individual confit container you could just throw in the fridge. That would certainly make it easier than digging a leg out of a crock when you wanted to just have one. Doing it with plastic wrap doesn't seem worth it.