Smoke Rings

Ol' Mississippi teaches me something new all the time. I always thought that when you smoked a brisket, the smoke-ring was caused by the amount of smoke making its way into the meat. Turns out I'm wrong:

Note the pink "smoke ring". The smoke doesn't actually turn the meat pink. The ring is the result of the meat being cooked at a low temp in a closed environment. The fire emits gasses that dissolve in the moisture on the surface of the meat. New compounds are created which are similar to the nitrates that are added to deli meat to keep them pink.