Tin Foil

lauraashley, Jan 20, 6:08am
I was always told wrap shiny side in (that was a few years back!) -- anyone been told different?


lilyfield, Jan 20, 6:32am
no one ever told me- I just use any old way

elliehen, Jan 20, 6:59am
That's what the experts say - I'm sure there's a scientific explanation.

It always feels back to front to me ;)

alebix, Jan 20, 7:32am
I always have shiny side out, its more reflective for the heat etc...

jessie981, Jan 20, 7:33am
Shiny side out, but don't know why.

kiwibubbles, Jan 20, 8:55am
so you want the heat to reflect away from what you have wrapped up?

falcon-hell, Jan 20, 7:52pm
snap.

elliehen, Jan 20, 9:09pm
That makes scientific sense to me :)

elliehen, Jan 20, 9:15pm
Well, it still bothered me so I went to Google ;)

"Short answer:I believe that the dull side should be out.

Long answer:

That would be my answer too.The only real scientific basis that I can think of for this answer is:Radiative heating / cooling.The goal is to maximize heat transfer.Heat transfer can happen by
CONDUCTIVE, CONVECTIVE, and RADIATIVE means.

Conductive heating will happen by the hot grill in direct contact with the foil.This mode is limited by the thermal conductivity of the foil.

Convective heating will happen by the hot air movement around the foil and transferring its heat to the surface.Then it will also be limited by the a heat transfer coefficient based on how fast the air is moving and of course the temperature difference between the
foil and the hot air.

Radiative heating will happen by the absorption of infrared radiation (IR radiation) or heat emanating from all around the food (within the BBQ).Now please consider infrared radiation to be in the wavelength range of 880 nanometers or so.Realize that this
wavelength of "light" is very near the color red in the visible portion of the spectrum. Further, this means that the radiation will act like light and the foil shall act as a mirror.Knowing now that you want to transmit (foil to absorb all radiation) as much IR
through the foil as possible.It should be clear to you that the dull side should be OUTWARD facing so as not to minimize the reflection of IR radiation."

Just remember that if you're suffering from hypothermia and someone is trying to wrap you in a survival blanket, make sure they wrap you up with the shiny side IN to keep you warm!

lauraashley, Jan 22, 5:10am
Thanks Elliehen, I actually read all of that! That explains why things actually keep slowly cooking after being wrapped in foil with the 'dull' side out.

jessie981, Jan 22, 6:04am
So if you're taking the food out you need to decide whether you want the food to keep on cooking.

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