All commercial pipe blends contain chemical casings. All of them contain varying constituents and concentrations. Like tomatoes bred for surviving transport, commercial pipe tobacco is engineered to survive its supply chain, yet arrive in a condition that meets consumers' expectation of "moist" tobacco. Add to that the predilection of most commercial pipe blenders for "improving" the pouch aroma and room note. So you have a chemical soup served up on a scaffold of tobacco....Stokkebey English Oriental Supreme. ...alarming dryness in my mouth. Is there a particular reason for that?
Beyond that, I have no answer.
Bob