Gonna go out on a limb here... I think perhaps we're talking about "soft cake?" The kind of cake that balls up in tar-like bits when scraped rather than has a crispy, rock-like nature? The kind of cake that when touched feels like earwax? The kind of cake that smells a little sour rather than a little sweet?
I used to have this problem in a few of my pipes. A few things contributed to this, and I studied it a little via personal trials.
* Pipe age--a seasoned pipe with an established cake seems to keep caking the right way a vast majority of the time...newer pipes can be susceptible to soft caking.
* Tobacco type--aromatics, usually saturated with propylene glycol can be a big problem. Propylene glycol never evaporates, but it will vaporize. If the pipe isn't brought up to temperature, the stuff can penetrate solid cake and turn it into a mess after a few bowls. Fortunately, smoking a non-aromatic mixture a half dozen times (and smoking it properly) will cure the soft cake into hard cake pretty quickly.
* Packing and tamping--if a smoker doesn't have a real "method" that works for him or her in these two realms, it may lead to some soft caking. Loose packing can throw out a glut of instant moisture and heat that only partially "cakes" a pipe. If this is done repeatedly, it's layers up on layers of cake that's only gone through half the process. Tamping comes into play because messing with the tobacco too much, mixing it around mid-smoke, playing with it, dumping out ash, defeats the dynamics that happen with the heating of tobacco during combustion--thus, half-baked cake.
* Resting--let your pipes take a break. If you're pounding them three times a day, every day, they may be a little moist. Some briars have different internal structure and grain than others, and will absorb (or resist) moisture better than others. That said, they also dry out at varying rates. I've found pipes that have softer cake (or softened cake) often are asking for a little more time to sit before the next smoke.
Combinations of any of the above can result in what seems like a "constant soft cake problem," for if you solve one, and not another, it can seem like a never ending battle.
Just keep it simple. Get decent tobacco, go slow, smoke full (or at least properly packed/tamped partial) bowls. Let pipes rest. Don't constantly fuss over cake, it can manage itself, and becomes obvious when it would like some attention.
These are simple devices, you just gotta let 'em be pipes, find your rhythm while interacting. They're patient, too--a lesson any of us could learn more about if we listen to 'em. :lol:
8)
