We've all experienced the frustration of an improperly packed bowl of tobacco. It doesn't matter how experienced we are; it doesn't matter how much we've read about pipe smoking or practiced our technique; it's irrelevant how expert we've become with various cuts of tobacco or different-sized bowls; we all mess one up now and again. Maybe it's one in 100, maybe it's one in 1,000, but we all find ourselves at some point with a pipe that won't draw correctly because we weren't paying attention when we loaded it.
When it happens to me, I don't realize there's a problem until I'm already applying the flame because I rarely take the common-sense precaution of drawing through the loaded pipe before lighting it. Maybe it's hubris: I've been doing this for so long that I don't need to pay attention, my subconscious probably tells itself, and I don't need no stinkin' draw check. But I think our subconscious waits for a distracted moment to demonstrate that our impudence is self-defeating. I don't know about you, but my subconscious luxuriates in surgical strikes on my self esteem.
So there I am, frustrated by the improper draw and the subconscious groin kick, and because I have no respect for my subconscious, I stubbornly decide I'll turn that bowl around and make it behave. The general rule for these situations is to empty the bowl and reload it, but my ego won't allow it. I apply the light again and pump air through the pipe to get it going, but it's no fun. Sometimes it feels like the air is traveling down one side of the bowl, sometimes there's little draw whatsoever, and sometimes I've loaded the bowl in such a way that the pipe whistles, which is intolerable. But maybe, rather than reload, I can make it work...
Once there's some good ash on the top after the first light, there's no going back. Some people in this situation find relief by inserting a tamper pick into the tobacco and loosening it, prying up from the bottom to introduce more space between the tobacco strands. In theory it should work but in practice it lets ash sift down to the heel and into the draft hole where it waits for the right draw and opportunistically hurtles into the mouth. Ash in the mouth is not acceptable. In terms of smoking satisfaction, a mouthful of ash is low on the scale, about even with smoking while being chased by hungry hyenas, which does not provide optimum relaxation.
How we find ourselves in this dilemma is simple enough. We've packed too tightly throughout or have packed one part of the bowl more tightly than the next, resulting in a plane of increased density somewhere in the bowl. I think of it as similar to a thermocline, which manifests in large bodies of water like lakes and oceans, as well as in the atmosphere. It occurs when temperature differs at different depths or altitudes so that one layer is a drastically different temperature and density. The air does not mix and the thermocline is like a hard plane that keeps the layers separate.
With tobacco, it isn't temperature but density, and it can be easily discovered by inserting a pick into the bowl. Most often, we'll find that the pick inserts easily until it hits a dense layer, sometimes so dense that the pick must be forced through it. That plane of density (not to be confused with the Spear of Destiny, which could theoretically work if you have on lying around) interferes with good smoking.
There's another technique, however; one that most of us have intuitively found, and it works almost as well as repacking the bowl: aerate the tobacco by pushing vertical holes into it.
One hole is generally sufficient, but multiple holes may be employed for particularly troublesome packs. Simply push the pick straight down until it reaches the floor of the tobacco chamber. Afterward, run a pipe cleaner through the stem and into the heel to make sure no tobacco has shifted to a position blocking the airway. Lighting after this procedure will result in a direct burn through the new hole, so it's best to tamp lightly over it and compress that new channel ever so slightly, so that the ember spreads and the bowl begins to burn properly throughout.
Once that's done, it's easy to smoke the bowl while thumbing our noses at our subconscious. Some call it cheating; my wife calls it stubbornness; I call it convenience.