Gemara

64b (Beraisa): A Yisrael may leave a Ger Toshav alone with wine in the Yisrael's store for a short time, even if the city is mostly Nochrim. He may not deposit wine with him for a long time, even if the city is mostly Yisraelim.

69a (Mishnah): If a Yisrael left a Nochri in a store with barrels of wine, even if he goes in and out, the wine is permitted. If he told him that he will not return for the time to pierce, seal and dry, it is forbidden.

70a: Reuven's wine was in a house. A Nochri entered and closed the door. There was a crack in the door. The Nochri was found between the barrels.

(Rava): The barrels that can be seen through the crack are permitted. Those on either side (outside the field of vision) are forbidden.

(Rava): If a Nochri was found near a Yisrael''s wine in an inn, if the Nochri would be considered a thief, the wine is permitted. If not, it is forbidden.

Question (Beraisa): If an inn was locked (and a Nochri was with wine inside), or if a Yisrael asked him to guard the wine (from the outside), it is Asur.

Suggestion: The Nochri has no excuse why he is there.

Answer: No, the case is that he has an excuse.

Rishonim

Rambam (Hilchos Ma'achalos Asuros 13:12): If one deposited wine with a Ger Toshav, or sent it with him and went away for a long time, or left his house open to the Chatzer of a Ger Toshav, one may not drink the wine. It seems to me that all Nochrim are the same regarding concern for switching and forging.

Beis Yosef (YD 128 DH Kasav ha'Rambam): Why does the Rambam say 'it seems to me'? The Gemara explicitly forbids depositing with a Nochri! Above (11:7), the Rambam wrote Stam that one may leave a Ger Toshav with wine, but one may not deposit with him! I think that the Rambam relies on his reasoning to forbid b'Di'eved if he deposited with him.

Rosh (5:16): When wine was left in an inn and a Nochri was found near it, Rava permitted it only if the Nochri would be considered a thief. Rashi explains that he is not considered a thief when he can justify why he entered. Even though he cannot justify touching the wine, it is forbidden. If he did not come to be Menasech, why did he enter?! This is unlike leaving a Nochri in one's store. Then, we permit if the Yisrael goes in and out. The Yisrael know that he is there, so the Nochri is afraid. Here, the Yisrael does not know that the Nochri is there, so he is not afraid, so it is permitted. If not, it is forbidden. Surely, he entered for Nisuch. Above the Gemara mentioned that he closed the door, and here it does not say so, the case is that he closed it, for we ask from the case of a locked inn. Since the door is closed, the Yisrael cannot see, so the Nochri is not afraid. If the door is open, he is afraid, even though the Yisrael does not know that he is there. We permit even when a Nochri is next to the pit (in the winepress - 60b), even though the Yisrael does not know that he is there, since he did not close the door. Also, when the door was closed but there was a crack in the door, even if the Nochri can justify himself, e.g. he has wine there, barrels that can be seen through the crack are permitted, because the Nochri fears. The same applies when the door is open. If he cannot justify himself, even if the inn was locked, it is permitted. Rashi says that when we permit, we permit even drinking. When we forbid, we forbid even Hana'ah. The Ra'avad says that we forbid only drinking. We forbid Hana'ah only if he deposited the wine for the Nochri to guard it without a seal. A Mishnah (Demai 3:4) says that Peros deposited with a Nochri are like the Nochri's Peros. Presumably, Rashi holds that (the Bach's text - presumably, Rashi is correct;) since we are concerned lest he touched, it is as if he deposited, so it is Asur b'Hana'ah.

Ran (31a DH Rebbi): Rashi explains that one may leave wine with a Ger Toshav in the Yisrael's store. Since the Ger Toshav does not serve idolatry, he will not touch or be Menasech it. We are not concerned lest he let another Nochri touch it, for it is a short time, and Nochrim do not regularly enter the Yisrael's store. One may not deposit wine in the Ger Toshav's house, lest other Nochrim touch it, for they are often in his house and he is not concerned if they touch it. Rashi connotes that if the Ger Toshav would touch it, it would become forbidden. R. Tam disagrees. If we are concerned lest Nochrim touched the wine, it should be Asur b'Hana'ah! Rather, we do not deposit with him for a long time. He is careful not to let Nochrim touch, but perhaps people will see the Ger bring wine from his house and say that the Yisrael drinks the Ger's wine (which is forbidden). We may designate wine with him, for a short time. We are not concerned lest he touch it; his touch does not forbid drinking wine. Even so,his Stam wine is Asur. The Rambam holds that a Yishmaeli is like a Ger Toshav. If so, we may leave wine with him, and we are not concerned about a Safek lest he touched wine, but if we know that he touched wine, it is forbidden.

Poskim

Shulchan Aruch (YD 128:1): If a Nochri was alone with wine, even in a Yisrael's Reshus, even for a short time, it is Asur b'Hana'ah. However, if we know that he does not serve idolatry, one may leave him with wine in our Reshus for a short time, in order to walk a Mil or more, even in a city of all Nochrim, even if he told him that he will be away for a while. However, one may not deposit wine in his house, and even in our houses it is forbidden for a long time.

Beis Yosef (DH v'Im): Rashi explains that one may leave wine with a Ger Toshav, e.g. he leaves him in the Yisrael's store for the time for the Yisrael to walk a Mil or more. One may not do so with a Nochri. Since the Ger Toshav does not serve idolatry, he will not touch or be Menasech it. He will not let another Nochri touch it, for he does not benefit from this. We are not concerned for switching in a short time. One may not deposit wine in the Ger Toshav's house, lest he switch it with his wine, which is forbidden.

Beis Yosef (DH u'Mah): The Tur says that the Nochri's wine is Asur because he is not concerned if other Nochrim touch it. This is like the Rosh, who permits drinking wine touched by a Nochri who does not serve idolatry. The Rashba holds that one may not drink wine touched even by a Ger Toshav, so in any case his wine is forbidden.

Beis Yosef (DH v'Yishmaelim): The Ran said l'Halachah that a Yishmaeli is like a Ger Toshav, for he does not serve idolatry (but not to rely on this in practice). Since this matter is mid'Rabanan, one may rely on the lenient opinions to leave wine with him, but not to deposit.

Beis Yosef (DH Kasav ha'Ra'avad): The Rosh favors Rashi, who forbids even Hana'ah. It seems that also the Ran (34a) does (he brings Rashi's opinion last). The Rashba (1:738) says 'my opinion will not resolve what the mountains argued about, but presumably when it is a Safek that he touched, it is Asur b'Hana'ah, like Rashi and the opinion that forbids (Hana'ah from) Stam wine of Nochrim.

Taz (1): There are two ways to explain the difference between Yichud (leaving him alone with wine) and depositing. The Tur holds that Yichud is for a short time, and depositing is for a long time. Rashi holds that Yichud is in the Yisrael's Reshus, without making him a Shomer on the wine, just he leaves the wine in the Yisrael's house with him. The Heter is because the Nochri has no Asur wine to switch in place of it. Depositing is in the Nochri's house. Nochrim go in and out. He does not care if others touch it. Therefore, the Shulchan Aruch is stringent to forbid both (definitions of depositing). It permits only in the Yisrael's house for a short time. Even though nowadays all Nochrim do not serve idolatry, l'Chatchilah one may not deposit with them. We consider them like idolaters, like the Rema says.

Shulchan Aruch (ibid): If he transgressed and deposited, one may not drink the wine.

Shach (3): This connotes that one may benefit from the wine. The Bach refuted this, for we permit Hana'ah only when we know that he did not touch. If not, it is Asur b'Hana'ah, for he lets Nochrim touch it. The Rosh and Tur forbid depositing lest he switch it with his own, which is surely Asur (b'Hana'ah), since he lets Nochrim touch it.

Note: The Bach (7) says that nowadays, even if a Nochri Vadai touched the wine, one may not drink it, but one may benefit from it. However, the Shulchan Aruch forbids Hana'ah if one deposited with a regular Nochri, so we cannot say that he teaches the leniency of nowadays.

Rema: Nochrim in Chutz la'Aretz, even though they do not serve idolatry, one may not leave them alone with wine.

Beis Yosef (DH Kol): The Rashba says that even though Nochrim in Chutz la'Aretz do not (sincerely) serve idolatry, rather they just continue their fathers' actions, since they pour wine in front of idolatry, we cannot permit to leave them alone with wine. Even b'Di'eved it is forbidden.

Shach (4): The Rema did not forbid b'Di'eved. He holds that the Rashba forbids b'Di'eved because he forbids benefit from Stam wine of Nochrim and what they touch even nowadays that they do not serve idolatry, for sometimes they are Menasech. We permit benefit from their Stam wine, so we permit b'Di'eved wine left with a Ger Toshav or Yishmaeli. A proof is from Sa'if 4. The Rema permits drinking nowadays even if a Nochri entered a house with a Yisrael's wine, even if he locked the door with a key and would not be considered a thief, if there is no concern lest he drank. Also Hagahos Ashri, the Tur, Tosfos in the name of Rashi, the Mordechai, the Agudah, Semag, Semak and Isur v'Heter hold like the Rema, unlike the Rashba.

Beis Yosef (DH Nitfas): R. Yerucham says that being considered a thief is if a Yisrael would catch him touching, the governor would apply to him the law of a thief. He is not powerful, and the governor can punish him. This is like Rashi (61b DH Im, i.e. he fears the judges).