Brining, with any kind of meat, is used to add flavor to the meat. The brine solution has a higher concentration of salt and flavoring than does the fluids inside the muscle cells. Osmotic pressure equalizes the concentration inside and outside the cells so that the flavor from the brine becomes part of the meat flavor. Also, the muscle tissue absorbs aditional water, making the bird juicier. Another way to obtain similar results is to inject the bird with a brine solution, or a broth made from bones and skin. Let it sit for an hour or two to let the solution distribute itself evenly through the meat.
Crispy skin is cause by heat and fat. The heat causes the moisture in the skin to evaporate, leaving a fat-crisped skin behind. Many people rub oil, butter, or lard onto the skin to help make it more crispy.
I don't use roasting bags because they trap the steam that would normally escape, creating a soft, steamed skin.
Myth - microwaves cook from the inside, out. Microwaves transmit energy by exciting the molecules they touch. The outside of foods radiated by microwave energy receive the most concentrated energy, absorbing it and heating. The microwave energy penetrates the food, but gets weaker as it goes because it is giving up energy as it penetrates. The outside gets hot first, but the inside is heated as well. So the food cooks faster because there are two heat sources, direct energy from the microwaves, and thermal conduction from the hotter outside of the food to the inside.
Just so you know, microwave energy is simply the same electro-magnetic energy used to transmit radio signals. It falls within a specific frequency range. Radars transmit microwave energy in a directional path, and have an antenna that is tuned to the specific frequency that is transmitted. The radar picks up the reflected radio waves and the electronics turns that reflected energy into a displayed reading on a screen, telling how far, and in what direction the object reflecting the energy is from the radar.
In my home town, at the height of the cold war, we use to have a radar that was so powerful, that if you dripped a cow in front of the transmitter, is would be cooked before it hit the ground.
Is there any wonder that the first microwave marketed was called by the brand name - Radar Range?
Seeeeeya; Goodweed of the North