When it comes to getting the maximum yield from the crushed material, a sifter grinder with an integrated pollen catcher is an absolute must. The finer the mesh size, the cleaner the ground-up outcome - the only thing that works even better is a pollinator.
Pollen, crystals, skuff, kief - dust in your grinderIf you don't just use a normal grinder without pollen compartment, but one with a filter to grind your herbs - especially very resinous herbs - you'll soon notice that the filter collects a kind of sticky dust in the lower compartment. This is not simple waste which can't be used for smoking, but a blend of very concentrated pollen and resin which goes by various names: Skuff, crystals, pollen or kief.
If you use a pollen grinder with a sieve so collect the dust, you can use it in many ways, it is very versatile. You can add it to your incense herbs or tobacco blend and smoke it or use it for culinary purposes. You can't, however, smoke the pure dust because it burns very quickly. But when you add this herbal concentrate to your tobacco, incense blends and bakery, it can turn out just perfect.
Removing the sticky pollen from your grinder may be quite tedious, depending on the herbs used and the amount of resin they carry. One good strategy is placing the grinder in the freezer for half an hour, then the crystals will come off rather easily.