Reference for Bava Batra 191:6

דרומאי מתנו משמיה דר' יהושע בן לוי ראשונים ודאי יין אחרונים ודאי חומץ אמצעיים ספק

[it is regarded as] certainly vinegar;<span class="x" onmousemove="('comment',' R. Joshua regards the contents as vinegar as soon as they begin to deteriorate in odour though the taste may still be that of wine. Since it is now proper vinegar, the deterioration must have commenced at least three days previously. ');">¹¹</span> prior to that, [as] doubtful.<span class="x" onmousemove="('comment',' Because it is possible that the deterioration, as regards odour, began immediately after the test, and this, according to R. Joshua who is guided by the odour, changes the character of the contents from wine into vinegar on the very first day. ');">¹²</span>

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