It is mainly a corn based brew and unlike malted barley, it is unable to created the enzyme, called amalyze, needed to breakdown starch. This enzyme is prevalent in one source, human saliva. So the workers at Dogfish Head got tested and then proceeded to grind 40 pounds of corn with their teeth. Since this seems unsanitary to you and I; Sam did mention that this mash produces the wort which is then boiled so as to kill any bacteria from the chewing. The Chicha beer also contained cinnamon and a some other herbs Sam had to ship in from Puru.
I do not know about you, but I would hesitate a little before drinking a brew that came from someones mouth.