Here is what you need to know. The pipes that are narrow in the middle of the bowl smoke hotter than those that are fatter, like bulldogs, apples, Rhodesians. The more briar a pipe has, the cooler it will smoke but the heavier it will be. Those with longer stems smoke cooler than those with short stems. Long is at least 6 inches. Severely bent stems make the pipe lighter in the mouth, especially if they touch your chin. They also bend the smoke, probably making it less inclined to bite. But bent pipes can be a little difficult to clean. Very tall pipes produce a longer bitter endsmoke.