Carryover

[g.johnson]

Thanks for the physics lesson, though learning physics from someone who thinks heat "travels" might be a fool's errand. 

Would you be more comfortable if it were said that heat "migrates"? Really, heat does flow from hotter to cooler. How should we describe it? I've been working with heat for thirty or so years and have usually refered to its transmigration as travels, moves, or flows. Now, that I'm thinking about it, I mostly say that it flows. (As evidenced by my unconscious use of it in my second sentence.)

Edit: Maybe you could get a carry over of 15 degress if you were cooking a whole pig and covered it after it came off the fire.

Radiates?

"Flow" is a good historical answer since heat was thought to be a fluid until the 18th/19th century.

"Radiate" only applies to one method of heat transfer (i.e., radiation). Conduction and convection being the others.

[tommy]

"Flow" is a good historical answer since heat was thought to be a fluid until the 18th/19th century.

"Radiate" only applies to one method of heat transfer (i.e., radiation). Conduction and convection being the others.

ugh. he gets smugger by the post.

[g.johnson]

How often do I get a chance to show off?

[Nick]

"Flow" is a good historical answer since heat was thought to be a fluid until the 18th/19th century.

"Radiate" only applies to one method of heat transfer (i.e., radiation). Conduction and convection being the others.

ugh. he gets smugger by the post.

Tommy, he's right. Heat "travels", or flows, by all three.

Taking the piece of meat in question, when you take it out of the oven a number of things are going to happen. For one, the meat is going to be hotter toward the outside of it than the inside of it. It will also be hotter than the air that's surrounding it once it's outside of the oven. So, by conduction, the heat inside the meat will travel to the meat that's even further inside and cooler. The meat that's closer to the outside will lose temperature as it flows to the cooler air surrounding the meat. By covering the meat with foil, less will be lost to the surrounding air and more will be driven toward the cooler (but still hot) meat in the middle.

But, say you don't put foil around it when it comes out of the oven. (I'll leave aside thin film boundaries for now.) The meat is hot and is Radiating its heat to the surrounding air which is cooler. At the same time, the heat from the meat is setting up air currents by means of Convection and the air is moving from the bottom part of the meat and then, because heat in air rises, travels up to the top and beyond - where it then loses its heat to the cooler surrounding air and falls to repeat the cycle. Foil restricts both the radiation and, if left a little lose, the convective currents.

Now, I have to get out of here and cook some chili. Heat transfer is easy compared to flavor transfer.

[tommy]

ugh.  he gets smugger by the post. 

Tommy, he's right. Heat "travels", or flows, by all three.

my comment had nothing to do with the thermodynamic properties of meat, as i agree with him. i was merely pointing out that he's a smug bastard.

Edited February 9, 2003 by tommy (log)

[Nick]

my comment had nothing to do with the thermodynamic properties of meat, as i agree with him.  i was merely pointing out that he's a smug bastard.

Maybe I haven't read enough of his posts. I haven't gotten the idea that he's a"smug bastard."

[tommy]

my comment had nothing to do with the thermodynamic properties of meat, as i agree with him.  i was merely pointing out that he's a smug bastard.

Maybe I haven't read enough of his posts. I haven't gotten the idea that he's a"smug bastard."

ok then.

[g.johnson]

my comment had nothing to do with the thermodynamic properties of meat, as i agree with him.  i was merely pointing out that he's a smug bastard.

Maybe I haven't read enough of his posts. I haven't gotten the idea that he's a"smug bastard."

Tommy has been busting my balls about being a smug European, Manhattanite, scientific bastard ever since I made some disparaging comment about Jersey.

[Nick]

Tommy has been busting my balls about being a smug European, Manhattanite, scientific bastard ever since I made some disparaging comment about Jersey.

Jersey? You mean that place where after you pull out of NYC on an Amtrak you ride through miles of chemical wasteland and drainage ditches filled with greenish/brown goop? The place that used to be called the Garden State because of all the truck farms that fed NYC?

Edited February 10, 2003 by Nickn (log)

[tommy]

Jersey? You mean that place where after you pull out of NYC on an Amtrak you ride through miles of chemical wasteland and drainage ditches filled with greenish/brown goop? The place that used to be called the Garden State because of all the truck farms that fed NYC?

ooo, twist the knife why doncha.

[Stone]

brining tends to draw out some moisture

What do you mean by that?

lay a fish filet on the cutting board and salt it. come back 10 minutes later and it will have sweated.

obviously, dunking pork in a brine overnight will have a different end result but the salt will still have an effect on how the meat cooks. i'm not saying so with a negative connotation either.

But surface salt and brine solutions produce two different results. Brining increases the moisture content of meat.

Wouldn't this have something to do with osmosis? If there's more junk dissolved in the brining solution than in the water in the meat, wont the water flow out of the meat to achieve an equilibrium? Kind of like water flowing out of your skin when you sit in the bath and start to pucker? I assumed that was why the brining water turns pinkish -- it's the blood in the water leaching out of the meat into the brine.

I think brining intensifies flavor similar to sun-dried tomatoes -- by leaching out the water and leaving the flavor behind. But that's a wild guess.

[gknl]

brining tends to draw out some moisture

What do you mean by that?

lay a fish filet on the cutting board and salt it. come back 10 minutes later and it will have sweated.

obviously, dunking pork in a brine overnight will have a different end result but the salt will still have an effect on how the meat cooks. i'm not saying so with a negative connotation either.

But surface salt and brine solutions produce two different results. Brining increases the moisture content of meat.

Wouldn't this have something to do with osmosis? If there's more junk dissolved in the brining solution than in the water in the meat, wont the water flow out of the meat to achieve an equilibrium? Kind of like water flowing out of your skin when you sit in the bath and start to pucker? I assumed that was why the brining water turns pinkish -- it's the blood in the water leaching out of the meat into the brine.

I think brining intensifies flavor similar to sun-dried tomatoes -- by leaching out the water and leaving the flavor behind. But that's a wild guess.

Actually, believe it or not, your fingers getting all pruney is due to the skin absorbing water, not losing it.

According to Wolke's What Einstein Told His Cook (pp 143-145), there are two processes involved with brining. One is osmosis where water travels into the cell from the brine (cells don't contain much water compared to the brine), making the meat jucier. The other is diffusion; cells don't contain much dissolved salt either, so salt ions travel inside the cells too, making the meat more flavorful. Once inside, the salt changes the protein so that it can hold more water and proteins holding water tend to be softer (more tender). Thus brined meat is jucier, more tender, and saltier (more flavorful).

Osmosis works with water pressure; diffusion with salt concentration. Two separate things.