Related על בבא בתרא 168:14

One who [intends to] take terumah from a barrel of wine and discovers that it is vinegar, if he knew it was vinegar [at any point] before he took terumah, it is not [valid] terumah (Ter. 3:1). But if it turned into vinegar [after he set it aside], behold, this is [valid] terumah. In case of doubt involving terumah, he goes back and takes terumah [a second time], the words of Rabbi Yosei, since Rabbi Yosei says, wine and vinegar are two kinds. But the Sages say, they are one kind.