Though there are numerous types of tobacco flavors, they generally fall in one of two categories: aromatic and non-aromatic. The lines between these two categories are often blurred, though. Much of this is due to the individual tastes of pipe smokers. One person may consider a particular type of tobacco to be aromatic while another person holds a different opinion. Things can get even more confusing when it comes to specialty or custom blends.
Aromatic tobacco is lightly mixed with flavorings like vanilla or cherry, which provides a scented smell and flavor to the smoke. Depending on how the flavoring is added, these types of tobaccos tend to be moister than non-aromatic tobaccos, which can cause issues when smoking them. A lot of the problems associated with smoking aromatic tobaccos can be avoided by purchasing high-quality blends, setting a portion out to dry prior to smoking, and carefully packing the pipe. Some people even blend aromatic tobacco with a little dry non-aromatic tobacco to reduce the overall flavor and moisture content.
Non-aromatic tobacco, then, do not have added flavoring. Instead, manufacturers focus on producing tobacco with good natural flavors such as spice, grass, and wood. They come from a variety of different places including England and the Black Sea region. This type of tobacco smokes cleaner than aromatics and tends to have more earthy tones. Some are naturally sweeter than others due to the sugar content of the type of tobacco plant used. Non-aromatics can be used dry or wet.
Aromatic tobaccos are not better or worse than non-aromatic and vice versa. Like different flavored cigars, the best type of tobacco for any one individual should be based on personal taste. Some people like the added flavorings of aromatic tobacco, especially since there are so many. Others prefer the natural taste of unflavored tobacco. It is a good idea to sample different flavors in both categories.
One concern that many pipe smokers have about aromatics vs. non-aromatics is the tendency for the scent and taste of aromatic tobacco to linger in the pipe. The oils from the tobacco can seep into the bowl and affect the taste of subsequent bowls of tobacco, even after a cleaning. To avoid this, it is a good idea to use different pipes, e.g. a pipe for aromatic tobaccos and one for non-aromatics. Thoroughly scraping out the cake and treating the bowl with salt and alcohol can also reduce or eliminate any lingering aromatic smell or taste.