Related for Yoma 112:2

One who purchases [one hundred logs of] wine from Samaritans on Sabbath Eve [that he intends to drink on Shabbat], and he forgot to separate [tithes from it], says, "Two logs that I will separate in the future, behold, they are terumah, and the ten [logs] closest to them are first tithe, and the nine [logs] closest to them are second tithe." And he deconsecrates [the second tithe and transfers its sanctity to money], and he may drink it immediately [relying on the separation that he will perform later], the words of Rabbi Meir. (Sukkah 23b:5, Steinsaltz tr.) But Rabbi Yehudah, Rabbi Yosei and Rabbi Shimon prohibit [this]. They said to him, to Rabbi Meir, "Do you not concede that if the wineskin [may] burst [and therefore he will not be able to tithe it in the future], [and thus] he has drunk from untithed produce?" He said to them, "When it bursts, [I will be concerned]." (Sukkah 24a:6.)