Perhaps the most important step in preparing cigar tobacco for smoking. After harvest, workers gather the tobacco leaves in large bulks (known as pilónes), moistening the leaves and allowing them to ferment. The pressure and the heat causes temperatures to rise, perhaps as high as 140 degrees Fahrenheit before the bulk is broken down and rebult. This process, called working the bulk, releases ammonia from the tobacco and creates a chemical change in the tobacco. Smoking unfermented tobacco can make a smoker ill.