Premium cigars differ from cigarettes in one big way—cigarettes are wrapped in paper or, as the National Cancer Institute puts it “other substance that does not contain tobacco”, while cigars are 100 percent tobacco through and through. But there are big differences in what’s inside each of them as well. Cigarettes typically contain a blend of heat-cured and air-cured tobacco. Premium cigars also contain air-cured tobacco, but there’s a big difference—cigar tobacco is fermented as part of the curing process. Cigarette tobacco isn’t. Fermentation is what gives cigar tobacco its distinguishing characteristics, and what makes it taste and smell different from cigarette tobacco. During the fermentation process, cigar tobacco is literally cooked—not on stoves or in ovens, but in tall piles, called “burros” or “bulks”. If you’ve ever built a compost pile, you’ll recognize the process—the piles generate heat, which is what cooks the tobacco. When the piles reach a certain temperature, they’re taken apart and restacked, which starts the whole process over again and ensures even fermentation throughout. This process, also called “sweating”, changes the chemical composition of the leaves as moisture, sap, and ammonia nitrate are released from the leaves. The starches in the leaves also convert into plant sugars, and the leaves darken in color. The process also reduces the nicotine content in the leaves. Cigarette tobacco also loses some nicotine during its curing process, but since it’s not fermented it doesn’t lose as much. It also doesn’t go through some of the other chemical changes that cigar tobacco does. While the fermentation process delivers tobacco with the characteristics that cigar smokers desire, it doesn’t make cigar tobacco any healthier than cigarette tobacco. Lower nicotine levels are offset by substances like nitrates, nitrosamines and several other known cancer-causing substances that also form during fermentation and that cigarettes also contain. What cigar smokers don’t get when smoking their favorite sticks are all of the other additives that go into cigarettes, such as carbon dioxide, which is used to treat some of the tobacco that goes into the finished product, and other added substances—plasticizers, sugars, and flavor additives among them.