Smoke ring (cooking)

The pinkish color in meat is typically due to the presence of a compound called myoglobin.

Organic fuels such as wood and charcoal, when burned, produce nitrogen dioxide (NO2) gas.

The NO combined with the myoglobin form a stable pink molecule that does not denature in the heat.

The highest concentrations of atmospheric NO2 can be achieved in a smoker through the utilization of charcoal briquets, or wood fires; both of which are capable of producing up to 200ppm (parts per million) NO2 in the cooking chamber.

For this reason, keeping the exterior of the meat moist via basting or spritzing is often recommended.