Yerushalmi Avodah Zarah 4:8 ירושלמי עבודה זרה ד׳:ח׳

MISHNAH: One may buy a used wine-press from a Non-Jew¹⁰⁷Since it is stated later in the Mishnah that grape juice becomes wine only when it is collected in the cistern below the wine press, a wine press used by a Gentile does not have to be cleansed from the remainders of the Gentile’s pressing before being used by the Jew to make kosher wine.. Even if he¹⁰⁸This now starts a new topic. The Gentile may help the Jew to load the grapes into the wine press even if the grapes are already oozing juice.. takes it in his hands and puts it on the pile¹⁰⁹“The apple” or “the swollen”. Any heap of organic material is called by this expression, so also the heap of ashes at the center of the altar in the Temple courtyard. Here it denotes the heap of grapes to be pressed.. It does not become libation wine until it flows down into the cistern. If it flowed into the cistern¹¹⁰The place where the juice flowing from the wine press is collected. As Rashi points out, European wine presses are not built over cisterns; there the place of the cistern is taken by the barrel into which the juice is collected.
If the Gentile touches the fluid in the cistern, the contents of the cistern become forbidden, the fluid still in the press is permitted. The status of the fluid in the pipe leading from press to cistern has to be discussed in the Halakhah., what is in the cistern is forbidden and the remainder in permitted.

HALAKHAH: “One may buy a used wine-press,” etc. Rebbi Ḥanin stated: Only if the Jew did not turn his eyes away from him¹¹¹The Gentile can help in preparing the harvest for pressing only if at all times a Jew sees him so one is sure that he does not touch the cistern or any storage barrels of grape juice. Quoted in Tosaphot 55b, Roqeaḥ #495, Raviah # 1096, Mordekhai #845, Rosh (Note 113).. But if he turned his eyes away from him, not then. So far if he¹¹²The Gentile. was taking juice and grapes together to put on the heap. If he gave these and those separately, (even from what was left in the fissures, what is under the bunches is forbidden, on the sides is permitted.)¹¹³The reading of Rosh (Avodah zarah4, #50) in the version of R. Lipman Heller Wallerstein and R. ḤID Azulai seems preferable:
הָיָה נוֹתֵן אֵילּוּ בִפְנֵי עַצְמָן וְאֵילּוּ בִפְנֵי עַצְמָן אֲפִילוּ כֵן
מוּתָּר. גוֹמָמִיוֹת שֶׁתַּחַת הָאֶשְׁכּוֹלוֹת מוּתָּרוֹת.
שֶׁבְּצִידֵּיהֶן הֵן אֲסוּרוֹת.
“If he gave these and those separately, even so it is permitted. The fissures under the bunches are permitted, on the sides they are forbidden.”
If the grapes are harvested into a vat, if the entire vat is emptied into the wine press one does not care if juice already oozed from the grapes since this is part of the pressing process. If the grapes are taken out of the vat and then the fluid is poured into the press separately, this also is acceptable. But if then some fluid is left in the fissures between the wooden planks which form the walls of the vat, it is grape juice in a separate vessel which is no different from a barrel standing under the pipe through which the juice flows from press to cistern; any touch by the Gentile will turn it into forbidden libation wine. Rebbi Yose ben Rebbi Abun in the name of Rebbi Joḥanan: Itself it becomes libation wine¹¹⁴He objects to making a difference between places where some juice is left; any juice left in the vat has the same status as juice in the cistern..

A wine press on which a Gentile stopped a leak from the inside is forbidden, from the outside permitted, for it is impossible that there not be wet bast where he touches and turns the entire cistern into libation wine¹¹⁵If the wine press were completely dry, there would be no difference whether the Gentile plugs the leak from the inside or the outside. But if it is moist, the bast which he uses to plug the leak retains some wine which then turns the wine press into a vessel like vat and cisterns, and the Gentile’s touch forbids the wine. But from the outside it never can be considered inside a vessel..

Rav Huna in the name of Rav: The jet is like the cistern¹¹⁶Babli 55b. The case of the conduit from wine press to cistern which was not treated in the Mishnah is decided: The moment when a drop of grape juice passes the filter at the bottom of the press and enters the pipe leading to the cistern it turns into wine.. Rebbi Ze`ira asked: Everywhere¹¹⁷The basic text is Mishnah Ṭahorot8:8 which states that any flow downwards is no connection for impurity while standing fluid on a level surface is. Babli 72a. you do not say that flow is connection, but here you are treating flow as connection? Rav Huna is of the opinion that if the cistern became libation wine, the flow became libation wine¹¹⁸In these matters, any defect is transferred upwards but not downwards.; if the flow became libation wine the cistern did not become libation wine¹¹⁹If the flow was cut off and prevented from reaching the cistern.. Rebbi Abba did not say so, but if the cistern became libation wine, the flow did not become libation wine; if the flow became libation wine the cistern became libation wine. What Rav Huna said in the name of Rav, the jet is like the cistern, for Rav Huna is of the opinion, just as the cistern becomes libation wine so the jet becomes libation wine. There, they say in the name of Rav, the touch of a Gentile makes libation wine. Rav Naḥman bar Jacob said, only when it is flowing¹²⁰A libation consists of shaking the wine as an homage to the gods. Therefore if the touch of the Gentile did not move the wine from its position at rest, no libation was made..

An Aramean fell into a cavity. The case came before Rebbi Huna who said, immobilize him¹²¹Since libation wine is created by a Gentile moving the wine, the Non-Jew has to be immobilized until the cistern is emptied. until you have emptied the cavity. Rebbi Ḥanina said, he is moving his hand. He said, bring willow baskets and approach from under his hand¹²²Hebrew and Aramaic זלף means “to sprinkle” (Note 161). This does not make any sense here. The word is Arabic زلف “to approach, advance toward”. One brings baskets or mats of willow weave and approaches his arms from below so that his hands are in the air above the wine and cannot move the wine..

Simeon bar Ḥiyya was instructing Ḥiyya bar Rav. Starting when does a Gentile make libation wine¹²³This seems to be a question which Ḥiyya bar Rav asked Simeon bar Ḥiyya.? He told him, from when he knows the nature of idol worship. (Rav Joshia left) [Rav put out his head]¹²⁴The translation [in brackets] follows the argument of S. Lieberman (Hayerushalmi Kiphshuto New York 1995, p. 226) that one has to read not אפיק רב יאשיה but אפיק רב ראשיה as in Eruvin1:1, 18d line 33. from the curtain and told him, you may say this if one buys grapes from the Gentile. But the Gentile proper makes libation wine when he is one day old¹²⁵Babli 57a, where Simeon bar Ḥiyya actively opposes Rav. Rav admits the leniency only for grape juice flowing from grapes in a vat. But in this case, even an adult Gentile was admitted as help. The leniency applies only to the juice left in the vat after it was emptied of grapes, cf. Note 113..

May a Gentile make libation wine with his mouth? Rebbi Ada in the name of Rebbi Eleazar: A Gentile cannot make libation wine with his mouth. Rebbi Jeremiah in the name of Rebbi Abbahu: A Gentile can make libation wine with his mouth. And we have stated thus: “If a market supervisor¹²⁶This should read אגרנימוס Greek ἀγορανόμος “market supervisor”. tasted from a cup or from a suction pipe¹²⁷To check the quality of the wine, whetrher the customer would not be overcharged. and returned¹²⁸The remainder of the wine. to the amphora it is forbidden.” In the opinion of Rebbi Ada in the name of Rebbi Eleazar, only if the Gentile returned it¹²⁹Since they hold that the motion of the wine induced by the overseer’s mouth cannot make libation wine, if the Gentile returned it to the amphora he causes waves in the wine which makes it libation wine forbidden for usufruct.. In the opinion of Rebbi Jeremiah in the name of Rebbi Hoshaia, even if a Jew returned^129aFor him the wine drawn by the overseer is libation wine in all cases; the person who returns the wine to the amphora will make it forbidden in all cases..