What’s the halachah if a fly falls into the wine, may it still be used for kiddush? The Kaf HaChaim (s.k. 21) writes: “If the wine becomes wormy, however, the taste or smell is unaffected, and one sieves the wine to remove the worms, one may use the wine for kiddush.”
R’ Yitzchok Zilberstein (Chasukei Chemed, Succah 36b) speaks at length about a similar shailah. He discusses a case when Reuven came home from shul on Friday night and is about to make kiddush, and then he finds a bug inside the bottle of wine.
The Gemara in Succah (36b) discusses if an esrog that was pecked at by a mouse is suitable to be used on Succos. The Rema (649:5) rules: If an esrog has been pecked at by a mouse, one shouldn’t use it the entire Succos, as it is considered disgusting, If, however, the place where it was pecked at is removed then it’s suitable to be used for the mitzvah. The Shiltay Giborim (Avodah Zorah, 25a MiDafay HaRif) asks: What’s the difference between the case of the esrog, and the halachah (Orach Chaim 154:12) that if a mouse is found inside the shul’s oil, if the oil became disgusting it shouldn’t be used to light candles in the shul and it doesn’t help to remove it. Why by the esrog does removing the effected part help, whereas by the oil it does not?
The Kapos Temorim answers: Oil which had a mouse dissolve inside it is much more disgusting than a mouse simply eating from the outside of the esrog.
R’ Elyashiv (He’oras) answers: Candles in a shul are different as they are lit for kavod Beis HaKnesses and for kavod Hashem, like we learn: כבדו את ה' באורים – “Honor Hashem with light”, therefore, oil which had a mouse dissolve inside shouldn’t be used as it’s a lack of kavod. However, the esrog on Succos is coming for a mitzvah, but not for kavod, therefore, it’s not so bad that it’s disgusting.
R' Zilberstein writes: Seemingly these two answers will make a difference regarding the case of the bug inside the kiddush wine. According to the Kapos Temorim that the problem with the oil is that there was a mouse that dissolved inside the actual oil, then here as well, if the bug dissolved in the wine, it would be a problem (if however, it was taken out a live it may still be ok). According to R’ Elyashiv, however, that the oil is a problem due to kavod, and by mitzvos there is no problem, when it comes to kiddush such wine would seemingly be ok.
R’ Zilberstein suggests another answer to the contradiction between the case of the oil and the esrog, and suggests that a live mouse pecking from an esrog is not as bad as a dead one. In our case, if the bug was alive it would be ok, however, if it was dead then it would be a problem. He ends off tzorich iyun.
