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Searing Meat does NOT "Lock in the Juices" - Page 2

post #31 of 49
Allow me to expand on this a little...
As the water temp rises, assuming the paper cup is full, some water will spill over as it expands. keeping the cup full and moist. The water inside the cup will also keep the paper cup itself from getting to hot to burn....for a while...once the water is gone, and the humidity inside the oven is low enough....i think the paper would burn at 500 degrees.

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post #32 of 49
Correct again The Cat.

As long as liquid water is in contact with the paper, the paper will not burn (even if it rested directly on the oven rack). When water boils, it maintains a constant temperature of 100C (212F) (at sea level of course). Similarly, water in the freezer will stay at 0C (32F) until all of it turns to ice before going colder.
We know these points as boiling point and freezing/fusion point.

The principle applies in cooking. If liquid water is present, regardless of the heat applied to the pan, if the food is in contact with the water it will cook at 100C. If for example the pan is very hot and a steak is placed in it then the water in the meat vaporizes quickly and steams away from the surface. What happens is a thin layer of meat is dried. The water that was there is gone in steam and push towards the colder environment inside the meat.
Meat proteins usually like to hold on to water but if cooked at high heat they denature (goes from red to gray). Denatured proteins are insoluble in water hence cannot hold water. A seared surface will always appear dry because it cannot soak up water.
An extreme example of this is when you make boeuf bougignon and the meat cubes cook way too long. Even if cooked in a liquidy sauce the meat can actually be very dry. Overcooked proteins=cannot hold water.

The problem with the word juiciness in this thread is:
foodies relate juiciness with tenderness, moisture, mouthfeel and flavour.
Scientist relate juiciness to yield i.e. weight before and weight after and calculate how much water is retained.

I understand both camps and there are misconceptions and myths on both side. I have demonstrated how a seared roast beef prior to slow cooking loses more water then a slow cooked roast but is so much better tasting.
A seared surface does not seal the water inside. A lot of water is lost during the searing and not a lot after that because the moisture below the surface is pushed towards the colder center and will stay there until done. The resting time is good to equilibrate the temperature across the whole roast. A even temperature across the whole roast will have an even moisture. Moisture is related to temperature.

A well seared roast will eventually leak at the surface, if rested too long, because the surface proteins are more severely denatured.

(that was a tad too long an explanation....)
Luc H.
I eat science everyday, do you?
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post #33 of 49
FWIW, as a scout leader we used to, as a stunt, show kids how to boil water in a paper cup. This was over an open fire, mind you, which may or may not have the same effect as an oven.

Wherever water is in contact the paper doesn't burn. That's true. Why, because the flash point of paper is greater than 212F. However, exposed paper (i.e., anything above the water level) did not burst into flame. Instead, it would char, and burn away like that. But never with actual flames.

I have no explanation for why this is so. But anyone can observe it.
They have taken the oath of the brother in blood, in leavened bread and salt. Rudyard Kipling
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They have taken the oath of the brother in blood, in leavened bread and salt. Rudyard Kipling
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post #34 of 49
Siduri,

Starting with a cold pan, the meat will appear to sweat as it heats up. Atmospheric water condenses on the upper surface of the meat which is (a) the coolest local region, and (b) below the dew point. The sweat rolls onto the surface of the pan and collects until the pan is hot enough to evaporate it. Also, as the meat slowly heats up, moisture held in the interstitial areas between the cells begins to flow freely and exits the meat through surface pores. In a cold pan the liquid appears as liquid. In a hot pan the protein strands in the liquid contract and form fond -- a semi-solid.



Luc,

As long as there's water in the cup the paper will not burst into flame. This is because the paper transfers the heat energy it gains through convection to the water through contact immersion. Although localized areas of the paper cup vary in temperature, paper is a sufficiently efficient conductor to transfer enough energy to stay below it's ignition temperature. The tendency of systems to equilibrate temperatures is a function of what physicists call The Zeroth Law of Thermodynamics. It's the zeroth because it's so basic and so intuitive.

Finally, I'd like to correct what seems to be a general misapprehension in this thread. The boiling point for all of the water in the cup is not 212F (100C) -- even at sea level. That is, it won't all suddenly turn to vapor. The BP refers to the liquid/atmosphere interface and not the water below the surface. There, the pressure is higher and the BP rises according to depth. Water can be kept liquid at temperatures significantly above 100C by its own weight, and held in place by the meniscus surface tension alone. E.g., water superheated in a microwave. Under greater pressure, like the cooling systems of nuclear reactor, water can be heated to temperatures in excess of 300C without vaporizing.

Y'all each owe me a drink :beer:
BDL
post #35 of 49
Water won't instantly vaporize at 100 C because there's latent heat needed to boil it away. Latent heat is needed for phase change.

I've experienced superheated liquid water in a very clean pyrex cup when I was making tea. It didn't boil when I expected it to. 8 minutes of microwaving when it would usually boil in 5. When I opened the door of the microwave oven, somehow it got nucleation sites and boiled so furiously that most of instantly turned to steam. It was a good thing I didn't have my hand in there yet. It is regarded as a very rare thing, and I saw this very rare thing myself.

I'm not a chef by any means, but I am educated in chemistry and physics. I'm also very aware of the pressure factor involved in boiling point (or saturation point, as it is often called in my trade). I am an air conditioning technician now, but this is a new career for me at age 45. I worked at Hewlett Packard 17 years.
post #36 of 49
Sounds like somehow a vacuum environment was created, and when the different air temps and pressures inside the mike and out met, all **** broke loose.
post #37 of 49
I think that's likely Cat Man, now that you mention it. thx. Probably there was higher pressure in there until I opened it up.
post #38 of 49
Dr/Senor/Mr/Jeffe Luc will tell us for certain....I believe.

I was just guessing, sorta...

To me, this is as much logic (read: zero emotion in decision, emotional factor recognized and accounted for) as it is science, if not more.

Remember, when scientists (religious theologins originally, but same pig, prettier lipstick nowadays) declared their opinions as science? (Luc, this is not a bash on you or your peers at all, but I suspect you know what I mean)

Disclaimer: I'm currently reading World Without End, the Ken Follett sequel to Pillars of the Earth.....so I'm kinda living in the 13th century right now.
The crop harvesting technique storyline is really intriguing

Cat Man
post #39 of 49
"Finally, I'd like to correct what seems to be a general misapprehension in this thread. The boiling point for all of the water in the cup is not 212F (100C) -- even at sea level. That is, it won't all suddenly turn to vapor. The BP refers to the liquid/atmosphere interface and not the water below the surface. There, the pressure is higher and the BP rises according to depth. Water can be kept liquid at temperatures significantly above 100C by its own weight, and held in place by the meniscus surface tension alone. E.g., water superheated in a microwave. Under greater pressure, like the cooling systems of nuclear reactor, water can be heated to temperatures in excess of 300C without vaporizing."

BDL
I am slightly confused by your post.
The boiling point for all the water in the cup is indeed 100C, exposed or not. Aside from air pressure variables.

Once water molecules reach that temp, things change, period.
Outside of a contained environment, h2o turns from liquid to gas at 100C (sea level, more or less)

Yes, I understand surface temp vs immersed, but in this scenario we're discussing, immersed becomes surface at some point, eventually.
post #40 of 49
Sorry, the discussion has gone on while i slept - your day is my night -
anyway, this may well be true. However, once the pan is full of water, the meat boils, and the result is completely different to the palate (for one thing, my guess is the inside cooks through quicker resulting in meat that certainly tastes and feels drier - in the other posts i think someone said that when it's too well cooked protein won;t hold water) in any case, yuck.
"Siduri said, 'Gilgamesh, where are you roaming? You will never find the eternal life that you seek...Savour your food, make each of your days a delight, ... let music and dancing fill your house, love the child who holds you by the hand and give your wife pleasure in your embrace.'"
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"Siduri said, 'Gilgamesh, where are you roaming? You will never find the eternal life that you seek...Savour your food, make each of your days a delight, ... let music and dancing fill your house, love the child who holds you by the hand and give your wife pleasure in your embrace.'"
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post #41 of 49
Yeah, and be grateful you haven't. It's not a "method" - it's what you get when you get invited to dinner around here in practically every house i've ever been in. (italian home cooking is not what it's cracked up to be by any means). Not that they think about it, they just do it. They load a pan up with meat, packed together, because people don;t seem to have more than one frying pan and if they do they don;t have big enough stoves to hold them, and then when it's time to cook it they turn it on (to low usually). I've watched this time and time again when i'm a guest at a friend's house. I have to literally sit on my hands to keep from interfering. Don't get me wrong, i'll eat practically anything, and am grateful to any invitation to dinner both for the company and not to have to do the cooking. But it's a very trying test of my friendship to not say something (like AARGH!!! STOP!!!)

anyway, thanks to all of you for your exhaustive answers.
"Siduri said, 'Gilgamesh, where are you roaming? You will never find the eternal life that you seek...Savour your food, make each of your days a delight, ... let music and dancing fill your house, love the child who holds you by the hand and give your wife pleasure in your embrace.'"
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"Siduri said, 'Gilgamesh, where are you roaming? You will never find the eternal life that you seek...Savour your food, make each of your days a delight, ... let music and dancing fill your house, love the child who holds you by the hand and give your wife pleasure in your embrace.'"
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post #42 of 49
I'll start by quoting from Wikipedia

I was sloppier with language than I should have been in my previous post, and radically misused the term "Boiling Point." I didn't want to drag the discussion into science jargon. Not a particularly good reason, and confusing too. My bad. That cherry's certainly gone now. I'll try to be more precise.

My point was that there's a temperature gradient within the container itself; and if heat is applied to the bottom of a pan hotter temperatures exist below the surface than at the surface, even though water, at the surface is turning to steam. You see, that heat is going somewhere. The phase change can be retarded below the surface, so not all of it vaporizes instantly at BP -- and can be heated measurably higher. In a deep enough pan, even though roiling, the gradient is enough to serious effect thermometer calibration. I'm sure Yeti, in his professional life, learned to calibrate thermometers by placing the probe just below the surface, and waiting for a full, rolling boil before measuring.

Pressure, and/or containment can come from surprisingly simple sources. Surface tension alone can hold enough pressure for superheating.

I'm not sure what Yeti meant when he was talking about "latent heat." I know what the term means, although Yeti's term "heat" is not quite standard, "energy" is. And the term "latent" is archaic. I'm just not sure what Yeti meant. The modern (since the mid 20th Century) term for latent energy is enthalpic energy. However Yeti seemed to imply that some special energy other than the energy which brought the liquid to BP is necessary for phase change. If the implication is not just sloppy reading on my part, or sloppy writing on his, then: No. enthalpic energy can be and usually is heat energy from the same source. But it's that extra wee bit (to use a scientific term) the system needs for phase shift after the liquid hits BP temp. Meanwhile the temperature of the liquid at the surface stays about the same. This is a function of the No Free Lunch Law of Energy.

The term "latent" (meaning hidden -- as opposed to "patent" meaning obvious) was originally used, because although heat energy was added to the system, temperatures did not increase. Now that we have a quantum understanding of enthalpy (H = U + pV) we're more precise.

There's some recognition of enthalpic energy in the term saturation temperature which is the temperature at which a given liquid hits its saturation pressure and undergoes phase change -- either gaseous or solid. "Saturation" refers is from the energy required for the phase change. I'm not familiar with the term "saturation point" used in this context.

Yeti actually covers a manifestation of these phenomena in his description of the superheated water in the microwave. Superheated means it was super hot. Super as in a lot higher than boiling point. What held it in the container? Surface tension -- the same thing which allows a bug to skate on a pond. Not vacuum or low pressure as you guessed. FWIW, it's not everyday, but not all that uncommon either. The FDA has warnings on microwaves.

Remember the deep pan with the temperature gradient?, with the heat applied to the bottom? As the water is heated, air dissolves out of the water and breaks the surface tension with small bubbles. Then the water at the bottom reaches its BP before the water at the top, some of it turns to steam, which forms bubbles, which then rise to the top, keeping the surface moving and a meniscus from forming.

Educational background seems to have reared its ugly head here, and it's a lane down which we probably don't want to go too far. It becomes competitive, feelings get hurt, CV's get fraudulated, and too many people with too much to offer feel excluded.

At any rate, returning to the intersection of science, educational bona fides and cooking, when I was an undergrad in the late sixties - early seventies, I took Organic Chem from a professor named Calvin. Dr. Calvin was, among other things, a Noble Laureate. He used to laugh about how dumb housewives were because they believed a simmer would cook differently than a rolling boil -- when they were both 100C and obviously, ab definito and a priori would cook just alike. QED, what a maroon! Not to mention an officious, sexist pig.

Finally, I'm not sure if science was ever principally in the hands of "theologians." There were some important "natural philosophers" in the medieval church, but they tended not to be theologians. Not important ones, at any rate. Part of this is due to the shift in Catholic theology from Neo-Platonism to Aristoteleanism around the 13th C. Aristotle's deductive logic was very helpful with math (think Descartes, Pascal), but not with science, per se. It's true though that two of the medieval leaders of the inductive revolution in thought which became scientific method, and eventually modern science actually were priests who made important theological as well as natural-philosophy contributions -- Robert Grosseteste and Roger Bacon both of whom argued for "empricism" and induction.

Should I mention that Occam's contribution to science is overrated, and that his "razor," is almost never stated in any way to which he would agree? Or that when people claim to use it, they almost always use it wrong? No? Oh, well.

Important medieval and renaissance contributions were made by non-priests as well. Our modern understanding of European science in the middle ages is that it did go on, and not only in the priesthood. And outside of Europe, the Islamic world was certainly active. Indeed, Europe borrowed heavily both in technology and thought. When it comes to the renaissance, think of Brahe, Galileo and Newton. Not a priest among them. Brahe was an anti-priest if ever there was one. Galileo's relationship with the Church was hardly friendly. Actually Isaac Newton was something of a theologian (very weird, don't ask) if not a priest. But, even looking back from our modern day there was nothing quaint about Newton's renaissance science. Smartest man that ever lived? Maybe. For that matter, Bacon warn't no slouch neither.

Well it's not me,
BDL
post #43 of 49
Boar_D_laze I will be honest here I have not read your last post completely yet....

I read enough to say this: yes there is a gradient of temperature in depth but in a glass of water or even a deep pot that effect is entirely negligible and of zero consequence in cooking. The main reason why is because water heated from below has convection currents circulating upwards and falling downwards which mixes and creates an even mean temperature throughout a small volume of water relatively speaking. All the water must attain a temperature of 100C (at 1 atmosphere of pressure, sea level) to start the phase change process. Additional heat is required to actively create steam.

The temperature gradient as per water depth explains extreme conditions like for example, Excessive water temperature (above 100C) around volcanic vents in the the deep ocean.

Super heating conditions happen when the applied heat is less directional like in a microwave where the heat is applied relatively evenly throughout the liquid (little or not convection currents). When this happens, nucleation is the clincher to break the equilibrium for spontaneous burst of bubbles. Water cannot be liquid at above 100C but the conditions in the microwave can trick water into this state. These liquids are flukes and are highly unstable.

Superheated water is like opening a pressure cooker already pressurized: boom. The water inside a pressure cooker is around 120C only because it is under pressure. If you suddenly open the lid and water at that temperature must turn to steam (very quickly).

Siduri,
I have been to those type of dinners... I hear you.. I also sit on my hands.

Luc H.
I eat science everyday, do you?
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post #44 of 49
You're missing the context of the entire conversation. Or at least my part in it.

That is as it may be. However, to move back into the cooking context, you need to discuss whether the surface temperature of a pan with a small amount of water can be at a temperature above water's BP. This goes to a question Siduri originally raised, i.e., whether meat can ever sear in a wet pan. I didn't answer the question because I don't know whether the Maillard reaction is scotched more by the presence of water on the meat's surface interfering with the chemistry of the reaction, by the efficiency of immersion conduction in carrying heat away from the meat, or by the efficiency of immersion conduction in dissipating heat from the pan preventing the surface of the pan directly beneath the meat from reaching the 175C threshold for a (relatively) fast Maillard.

Meanwhile, Yeti answered with what I suspected was speculation. I asked some questions, and the conversation shifted from searing to some of the nuances of BP. Returning to Siduri's question: I speculate some combination of the factors I raised above. Do you happen to know?

To return to the scientific knowledge context, you need to address Cat's contention (at least as I understand it) that at 100C+ all water in an open system instantly turns to steam.

Within the context of the conversation this might or might not be interesting (in the mathematical sense of the word -- that is, both true and informative). However, it does not go to Cat's (erroneous) contention that once a water molecule reaches BP temp[slightly restated, but sic], vaporization instantly occurs. I attempted to (a) explain that just ain't the way it happens; and, (b) talk about one or two of the reasons it ain't. Also, your expression, "an even mean temperature throughout a small volume of water relatively speaking" is meaningless. Relatively speaking. I think you meant, "within a small volume of water temperature differences from place to place are also small." If so, that's true. However, your explanation of "convection currents," if by which you meant advection was not quite so true. In fact, the principal method of heat transfer in a small volume of water is by the diffusion of Brownian motion. If by "convection" you meant the combination of advection and diffusion then your statement is true, but not informative.

Yeti was circling around this, using the term latent heat, although he was a little unclear -- not that I can throw stones. I actually discussed this in the post to which you're responding, using the term enthalpic energy. As I said, "No Free Lunch."

That's an extreme example. But the temperature gradient effect is linear. It's just bigger at higher pressures -- doesn't mean it doesn't occur at lower.

Here, your use of the term "convection currents" clearly implies advection to the exclusion of diffusion. Does that apply to your previous use?

When you said, "[C]annot be liquid .... but conditions ... trick water into this state." (?!!) You didn't really say that, did you?

Also, I'm a little unsure about your characterization of "applied heat," in a microwave. A microwave doesn't work by "applying heat," or even heat energy, by which we usually mean energy in the infrared spectrum (003 - 4 x 10^14 Hz) is transferred by contact, radiance, or convection. By definition, microwave energy wavelength does not overlap infrared. That's what makes one micro and the other infra. A microwave oven applies (wait for it) [I]electro magnetic/I] radiation around 2.45 x 10^9 Hz. The energy cannot be transferred in any way other than radiation. The EMR actually increases the translational kinetic energy of the molecules within whatever it was you stuck in the oven. These molecules express their love as heat. The magnetron shooting said EMR is actually very directional. Very, very directional. It seems less directional though because of the degree of penetration.

Similar in the boom sense, but otherwise different. In the case of a pressure cooker, steam is superheated raising the pressure in the cooking vessel. The additional pressure increases the BP of the water in the vessel so the overall temperatures of both water and steam in the vessel are around 125C. In the case of the microwave, the surface tension of the water alone prevents vaporization. An interesting corollary to superheated fluid is a Bose-Einstein condensate.

We may be getting to a point where the precision in language required is out of proportion to the information which can be conveyed.

BDL
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post #45 of 49
Latent heat of evaporation is 540 calories per gram . . this is by no means "just a little bit". Even rapidly boiling water takes quite a while to evaporate.

I'm not sure why Wikipedia calls the term "latent heat" obsolete. It's very much alive and defined.
post #46 of 49
Ok let me take a break here to reread these last long post and make sure I understand everything before i comment again.
Luc H.
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post #47 of 49
I think this thread has morphed into something way different than the original intent. It doesn't have much to do with searing meat any more, and I am an offender. I'll let the seared meat rest.
post #48 of 49
Let sleeping dogs lie, let seared meat rest. Both are better off for it. It keeps their juices inside. :rolleyes:
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 Don't handicap your children by making their lives easy.
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post #49 of 49

wow

your totally right. i ****ing cant stand it when i see a beautiful piece of meat ruined by seizing up by having over excessive heat and carelesness due to lack of knowledge of basting and resting
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