It could be slightly acidic to ever so slightly basic, but the mouth is pretty much a neutral environment.
This is a very acidic environment- no where else in the body is like this!
This environment is neutral, or even slightly basic.
The chyme that leaves the stomach is extremely acidic
The pancreas releases pancreatic juice into the small intestine, which contains basic chemicals that bring the pH level of the chyme up to about 7 or 8.
Pancreatic juice helps to neutralize acidic chyme that moves from the stomach to the small intestine.