Cigars and Science. Physics and Thermodynamics

Cigars and Science.

Physics and Thermodynamics 

   In recent years, the art and science of cigar smoking have garnered increasing attention from both enthusiasts and researchers alike. A comprehensive understanding of the physics involved in achieving the perfect cigar smoke session has emerged as a topic of significant scholarly interest. I this article we go into the fundamental principles of physics that contribute to an optimal smoking experience, shedding light on factors including airflow, temperature, and combustion.

   At the core of a perfect cigar smoke session lies the intricate relationship between airflow and the burning process. When a cigar is lit, the combustion of the tobacco generates smoke, which is propelled toward the smoker's mouth through the act of inhalation or puffing. The rate of airflow directly influences the temperature at which the tobacco burns. Research indicates that a slower, more deliberate puff allows for a cooler, more flavorful smoke, while rapid inhalation can lead to overheating, resulting in a harsher taste and diminished enjoyment.

   The schematic below shows the cigar’s anatomy with the head, body, foot, and cap; its structure with the filler, binder, and wrapper leaf; and the zones for the different processes that take place in the cigar during smoking, such as the combustion, pyrolysis, and condensation zones. By: Chemical Engineer, Ed Fontes

   Temperature control is another critical factor that affects the quality of cigar smoke. The ideal smoking temperature is typically around 70 to 75 degrees Fahrenheit. At this range, the volatile compounds in the tobacco are released optimally, providing a rich and complex flavor profile. However, if the temperature exceeds this threshold, the chemical composition of the smoke can change, leading to an unpleasant experience for the smoker. Therefore, understanding the thermal dynamics of cigar smoking is essential for enthusiasts seeking to maximize their enjoyment. Moreover, the physical structure of the cigar itself plays a pivotal role in the overall smoking experience. Factors such as the cigar's ring gauge, length, and density of the tobacco blend can significantly affect the draw and airflow. A well-constructed cigar with an appropriate draw allows for a balanced flow of smoke, enhancing the flavor and aroma. Conversely, a tightly packed cigar may restrict airflow, resulting in an uneven burn and compromised flavor.

      Below are the results from a simulation of a relatively simple model of a cigar during a puff and between puffs. The model describes the combustion and formation of carbon, in addition to the pyrolysis of tobacco. We also included the transport of oxygen, smoke, and nitrogen in the model. Of course, in reality, the process is much more complex from a chemical engineering perspective, but the model provides a nice and simple view of the temperature distribution in the smoke and oxygen concentration.

The temperature distribution of smoke.

The oxygen concentration in a cigar.

   Temperature distribution of the smoke in a cigar (top) and concentration of oxygen (bottom). The oxygen concentration dramatically decreases in the combustion zone during a puff. By: Chemical Engineer, Ed Fontes