This problem is typically referred to as “cottonmouth”, as it feels about the same as shoving a bunch of cotton-balls into your mouth, and then trying to lick a stamp.
It was once thought that dry mouth was merely a side-effect caused by the hot smoke that is inhaled when smoking cannabis. However; it is actually not that easy of an answer at all.
Over the years it has been found that cannabis consumption will cause dry-mouth, even when it is not ingested in the smoked form. The mere fact that even when eaten or consumed in a liquid beverage, cannabis will still cause dry-mouth, means something else must be at play here. We simply can not blame cottonmouth on the smoke.
Now, knowing that any form of ingested cannabis – weather eaten, or smoked, will cause cottonmouth – we have to look further into how cannabis works with our body, in order to figure out just how and why, our mouths get so damned dry, when we consume this wonderful herb.