AND.............
the only real and SAFE guideline in breaking a fast to completion is the return of genuine hunger, and where the tongue may not have cleared before that point is reached...............
"The primary indication that the fast is to be broken is the return of hunger; all the other indications are secondary. Often one or more of these secondary signs are absent when hunger returns, but one should not refrain from breaking the fast when there is an unmistakable demand for food, merely because the tongue, for example, is not clean. Inasmuch as all the signs do not invariably appear in each case, do not hesitate to break the fast when hunger returns".
Dr H M Shelton.