" [color= rgb(24, 24, 24)]Sugars or any ingredient that carmelizes, causes good bark (some feeling that turbinado sugar is better) "...[/color]
[color= rgb(24, 24, 24)]Not entirely true. A well prepared Beef Brisket or Pork Butt will have a great bark with the only the addition of Salt and Pepper or some Garlic Pwd, Onion Pwd and a little Cayenne for kick. This happens because of a breakdown of the meat Proteins into Amino Acids and their reaction with existing Carbohydrates in the muscle fibers independent of added sugar. [/color]
" The level of humidity in the smoker has not been agreed on whether it is a significant factor."...
Yes and No...High humidity in a short smoke will most definitely Inhibit bark formation. Bark is a balanced combination of the meat surface, Drying out, Undergoing the protein changes that develop Color and Flavor during the Maillard Reaction and the Caramelization of Sugars both naturally occurring and/or added. The 2-3 hours it takes to get a 5Lb Rib Eye Roast to 130*F IT at a Smoker temp of 225*F will have a near Zero Bark formation in a highly humid smoker. Conversely a 15Lb Beef Brisket smoked at 225*F for 20-25 hours will develop a great Bark regardless of Humidity.
" Bark can be built on most any meat smoked and is not limited to one or another. "...
Not exactly. Different meat protein densities and compositions under go the Maillard Reaction at different temperatures and to varying degrees. While Red Meats will pretty much all develop Bark at about the same time for a given temp. It is next to impossible to to get any type of Bark on Chicken/Poultry or Fish. At best you can expect some browning of the Chicken Skin and to a lesser extent the exposed meat at Smoker temps but no true Bark. Not to mention that by the time a good bark developed the Chicken would be inedible. The same holds true for Fish with the addition that the required Temperature to Brown Fish is well above 400*F and is not readily accomplished without the use of a Fat and being in physical contact with a Pan/Hot Surface or using the Radiant Heat generated by the 600-700*F temps of a Grill.
I'm not sure what you were looking for or what format you wanted but I hope this info helps...JJ