I am a complete novice, and have a question on what I am tasting. I have both Frog Morton and Penzance. The first one third to half bowls with each tastes light and pleasingly "sweet"; maybe sweet is a bad term, but I mean comfortable, light and tasty to me. The last two thirds to one half of the bowls tastes sour; not bad sour, but not as pleasant, again to me, as the first part. As an aid to deciding what future pipe tobaccos to get, would anyone care to speculate on what I am tasting in the last part of the smoke? Perhaps latakia? Bare in mind that my only other experience to date has been with a mellow burley. I have not tried any of the Virginia tobaccos. Thanks!