It's the powdered weed, once it's rolled it basically becomes compacted into a solid cylinder of marijuana and air isn't able to be pulled through the pot. Like the man said before, semi-crumbly weed is far better. Also hand rolled joints seem to burn far better than machine rolled, in my opinion.

It probably seemed more moist after you unrolled it because of the resin from the few hits that were taken.

Sayonara!