Cigar in dynamics
Burning of a cigar is divided into two phases: active (when you are actually drawing) and passive (between the draws). While you are drawing the air is sucked into the cigar body through the incandescence zone, and thus the smoke flow, which is called mainstream, is formed. In between the draws, the air goes upwards around the incandescence zone sustaining burning and producing the smoke flow which is called sidestream.
Not all the scents can be smelled through the nose. The lightest, or volatile, scents are dissipated and quickly disappear, the smoker just misses them. All chemical substances with the boiling point of 100°C or less are called volatile. The substances with the boiling point between 100 and 200°C are called semi-volatile. All substances with the boiling point of more than 200°C are considered heavy scents.
The temperature in the incandescence zone reaches more than 800°C. Along the cigar body the temperature falls to 600, 300, 200, 50°C etc. Heavy scents are retained by the cold tobacco leaves while more volatile scents continue to flow with the smoke. Such dynamics is typical of the first third of the cigar. At this stage the smoker receives the lightest scents with the smoke. But the fire front moves to the end of the cigar, the hot smoke warms it gradually and, finally, along with the light scents still heavier scents appear.
Each new draw creates a new wave of scent which differs from the previous one because the cigar warms up with each draw. Thus heavier scents such as truffle, chocolate and ginger appear. Those scents can not be distinguished in tobacco in the beginning and this phenomenon is called cigar smoking dynamics.
The last third of a cigar acts as a filter. Many heavy scents, as well as nicotine, settle down here. Thus the smoke acquires more strength. Beginning aficionados usually leave their cigar after the second third, but some enthusiasts like to smoke it to the very end.