Related su Terumot 8:14

One who takes terumah from a [wine] tank and finds it uncovered, or a watermelon and finds it to have bite marks (Ter. 8:6), it is [valid] terumah, but he goes back and takes terumah [a second time, as the first terumah involved hazardous conditions]. [Apropos of wine,] Rabbi Yishmael son of Rabbi Yosei says in the name of his father, we take terumah from wine on behalf of vinegar, but we do not take terumah of vinegar on behalf of wine, except according to the proportion.

One who eats untithed produced makes repayment from the gleanings, from the forgotten sheaves, from the peah (the corners of the field set aside for the poor), and from produce that has not grown at least a third, the words of Rabbi Eliezer. [But] Rabbi Akiva says, we do not make repayment with something that is not subject to tithes. [On the subject of eating untithed produce,] said Rabbi Natan, "Rabbi Eliezer would say, [with respect to one who began casually eating a cluster of untithed grapes in the field (see Ter. 8:3, Beitzah 35a:10-11)], he is permitted to wait until the arrival of the Sabbath and exit the courtyard and finish [eating them in the field]."

[Wine in a container attached to] a strainer is forbidden due to exposure. [But] Rabbi Nechemiah says, if [the portion of the container topped by a strainer] was underneath, it is [considered] covered, even though the upper part was exposed. Behold, [the wine within] is permitted because a snake's venom is like a sponge, and it stays in its place.

[With respect to] water that has been exposed, we do not pour it into a public thoroughfare, we do not knead clay with it, we do not permit a Gentile to drink from it, nor the livestock of others, but [if one chooses,] one may give his own livestock to drink exposed water. One may not sprinkle it on his house, nor may he wash his face, his hands, or his feet with it. Others say, [the Sages] were only talking about an instance where he has scraped [his face, hands, or feet, and thus the presumptively poisoned water would penetrate his skin]. And how much water [is required to dilute the poison (Ter. 8:5)]? [For exposed water] on the ground, 40 seahs. Others say, 200 [seahs], whether dispersed or scattered. Rabbi Nechemiah says, enough to fill a swimmer's barrel (see Beitzah 36b:15).

A[n unsealed] flask that is placed in a litter or a chest [and then forgotten], behold, it is forbidden (see Y. Ter. VIII.3.21). [If] he checked them (i.e., the litter or the chest) and then placed it there, behold, it is permitted. [With respect to] a flask in its case, behold, it is forbidden. [If] he checked and then placed it there, behold, it is permitted. If he put it in a pit, even if it is one hundred amot deep, behold, it is forbidden. [If] he put it on top of a tower, even if it is one hundred amot high, behold, it is forbidden. [If he places it in] his drawing room (טרקלין), even if it is lime-plastered and decorated (i.e., like a palace, where one would not expect to find a snake), behold, it is forbidden. [If] they were covered but not corked, or if the cork is split (per MS Erfurt, adding "חוצץ"), behold, it is permitted. How big must the hole be [to render the flask susceptible to poison]? Big enough to stick a child's little finger inside. [With respect to] puncture marks in cooked foods or cabbage stalks, and anything that is moist, it is forbidden (see Ter. 8:6). Rabbi Shimon ben Manasya says, he can throw out [the portion containing] the puncture marks and eat the rest. Mushrooms are forbidden due to the danger to life. A puncture mark in a fig that was made into a dried fig, [or] on a date that was made into a dried [date], both of them are permitted. [If] he saw a bird that made a hole [with its beak] in a fig, [or] a mouse that bit a hole in a watermelon, they are both forbidden, for I say, lest there were puncture marks [beforehand]. [If] a watermelon had puncture marks and ten people ate from it -- the remainder, behold, [remains] forbidden. And likewise with a barrel [of wine] that was exposed and ten people drank from it -- the remainder, behold, [remains] forbidden.

We may not mix together pure terumah [and] doubtful [terumah] (i.e., terumah as to which there is a doubt as to its purity, e.g., if it is uncertain which of two piles is pure and which is impure, see Lieberman) with each other, but we may mix together terumah that became impure through a secondary source of impurity with terumah that became impure through a primary source of impurity, even though impurity is added onto impurity. If he said, "This doubtful [terumah] is pure," behold, it is pure! If he said, "It is incumbent on me to wait until I find out about [its status]," behold it is impure! [If] a doubt arose concerning impurity in a loaf of bread next to him, [or] a doubt concerning the impurity [of a loaf of bread] on his table, he takes it and secretes it in a hidden place.

A jar that broke in the lower winepress, and the upper winepress [contains] impure [wine], all agree that it should flow down and create medumma [on its own accord], and not to make it medumma with his own hands. [Note: The GR"A, following Ter. 8:9, switches "upper" and "lower," and replaces "medumma" with "impure."]