Reference for Bava Batra 191:7
הא גופא קשיא אמרת ראשונים ודאי יין אלמא ריחיה חלא וטעמיה חמרא חמרא והדר אמרת אחרונים ודאי חומץ אלמא ריחיה חלא וטעמיה חמרא חלא
What is the reason? — Wine [begins to] deteriorate from below, and it is possible [that it had already] deteriorated [during the test] but he did not know.<span class="x" onmousemove="('comment',' And, consequently, despite the test, the contents were already, at that very moment, vinegar. ');"><sup>13</sup></span> [Moreover, even] if it is assumed that deterioration [begins] from the top, [and it will be argued that it must have been wine] since [this man] had tasted it and [ascertained that] it had not [then] deteriorated, [it may be retorted that] it is possible that it deteriorated [immediately] after he tasted it, [and it had] the odour of vinegar and the taste of wine, and [the law is that wherever] the odour is vinegar and the taste. wine, [it is regarded as] vinegar.