Leftover oil and wicks
This is the approved revision of this page, as well as being the most recent.
The extra oil and wicks
- One can add oil to the leftover oil and wick from the previous day and reuse it. If there’s leftover oil and wicks from the eighth day, it is forbidden and should be burned. That only applies if the oil and wicks were leftover before the mitzvah was fulfilled, meaning that the candle went out within the half hour of mitzvah, however, if the candles burnt for the half hour of mitzvah, the oil and wicks are permitted. Some poskim argue that anything that is put into the Chanukia is assumed to be set aside for the mitzvah and is forbidden. To satisfy all opinions, when putting the oil into the Chanukia one should stipulate that only the oil needed for the half hour of mitzvah should set be aside for the mitzvah.
- Many Poskim rule that it is permitted to discard the leftover oil in a “respectful” way even if the candles did not last for a half hour. 
- This only applies if the amount of oil was placed in the cup and it turned out that there was extra, however, if one originally filled the cups with extra oil it’s permissible. However, some are strict unless one made a stipulation that the extra oil is permissible. 
Extra oil in the container
- The unused oil left in the container, which wasn't poured into the Chanukia, is totally permitted. 
- Many say that it also permitted if it was poured into the Chanukiya but never lit.
Keeping the leftover oil around
- One who has forbidden oil should burn it and not keep it around until next Chanukah. Some, however, have the Minhag to keep it until the burning of Chametz. 
- Even though one isn’t allowed to nullify a forbidden object Lechatchila, after the fact if forbidden oil was mixed with 60 times that amount of permitted oil, the forbidden oil is nullified. If some oil was already added, then one is permitted to add more permitted oil to nullify it. Some say that even in that case one can’t nullify a forbidden object Lechatchila. 
- The wicks have the same halacha as the oil. 
- Shulchan Aruch 677:4 writes that if there is leftover oil from one night of chanuka, one may add oil and light it on another night of Chanukah. Rav Nassim Karlitz (cited by Piskei Shemuot pg 134) ruled that even if only the exact amount needed for the mitzvah was placed into the candles on one night and there is leftover oil, it is permitted to light with that oil on another night of chanuka. (Bei'ur Halacha 677:4 s.v. Min seems to support this.)
- The Pesikta Rabati (Pesikta 3) writes that if there is extra oil after the first night, one should add more oil and light it again on the second night. One can continue to add more oil and light each night, but after the last night, one should burn the leftover oil, since it is considered designated for the mitzvah. This Midrash is also found in Midrash Tanchuma (Naso 29). This Midrash is cited by the She’iltot (26), Tosfot (Shabbat 44a s.v. SheBaNer), Rosh (Shabbat 2:9), Smak 280, Mordechai (Shabbat 265-6), Roke’ach 226, Sefer Eshkol (2 Chanukah pg 20), Rabbenu Yerucham 9:1, Rabbi David Avudraham (Tefilat Chanukah), and Ohel Moad (Chanuka 2) quote this midrash as halacha. Tur, and S”A 677:4 concur.
- The Mordechai (Shabbat 266) wonders why the oil from the chanuka candles would be forbidden if one may blow out the candles after a half hour (S”A 677:2 based on Rif and Rosh 2:3). He quotes the Maharam, who answers that the oil would be forbidden only if the leftover oil would have been necessary for the candle to burn for a half hour had it not gone out. Hagahot Maimon (Chanukah 4:4), Sefer Eshkol (2 Chanukah pg 20), Bet Yosef 677:4, Sh”t Maharshal 85, and Darkei Moshe 676:5 agree. [The Ran (9a s.v. Iy Nami) seems to have understood these two opinions as contradictory as he comments that the Rif 9a who says one can benefit from the candle after the half hour argues on the Geonim who say that the oil is forbidden for benefit after the 8th day. However, from the Rosh and Tur who quote who halachot seem to think that these opinions are not contradictory.]
- Alternatively, the Mahari Avuhav (cited by the Beit Yosef 677:4) answers that if one puts in the oil without any stipulation, all of it is considered set aside for the mitzvah. If, however, one stipulates that only the oil that is necessary for the mitzvah will be set aside, then one may derive benefit from it after a half hour. The Bach 677:4, Pri Chadash 677, and Knesset Hagedolah agree. [Piskei Rid and Riaz (Shabbat 22a) and Rabbenu Yishaya Harishon (Shababt 45a) give a third answer that only on Chanukah it’s permitted and afterwards it’s forbidden.]
- Although the S”A 677:4 and Taz 672:1 agree with the Maharam, the Magen Avraham 677:10 and Mishna Brurah 672:7 write that it’s proper to make a stipulation that only the amount necessary should become forbidden in order to satisfy all opinions. Eliyah Raba 677:2, Chaye Adam 154:31, Torat HaMoadim 5:25 agree with the Magen Avraham.
- Tosfot (Shabbat 44a s.v. SheBaNer) ask why the oil isn’t permitted after chanuka just like other tashmishei mitzvah, such as the wood from a sukkah, are permitted after the mitzvah is finished (Megillah 26b). Tosfot answer that since chanuka candles are so beloved and a person is not waiting for them to be extinguished, he sets aside all of the oil for the mitzvah, and it is considered tashmishei mitzvah even past the time of the mitzvah. Similarly, the Ran (9a s.v. Iy) answers that since the oil usually is used up completely, a person automatically sets it aside for the mitzvah.
- On the other hand, the Avudraham (Seder Hadlakat Ner Chanukah) explains that the leftover oil is considered like a tashmishei kedusha because the candles are a zeicher of the candles in the beit hamikdash, which themselves are hekdesh. See also Sdei Chemed (Maarechet Chanukah 9:1), who first quotes Rav Shlomo of Vilna as having originated this idea and then says that he later found this explicit in the Me’iri (21a).
- Nitei Gavriel (Chanukah responsa #9) explains that according to Tosfot, the primary prohibition is not to derive benefit from it, but one may dispose of it respectfully. Even according to the Avudraham, he argues, one need not burn the oil and it is sufficient to bury it like other tashmishei kedusha. Similarly, Rav Hershel Schachter (Halachipedia Article 5773 #12) quoted Rav Schwab as saying that our minhag is not to burn it but rather to put it in a bag and discard it. Rav Chaim Kanievsky (cited by Piskei Shemuot p. 240) and Rav Shlomo Aviner (kimizion.org/maamar/wjw72a.doc) agree. See, however, Piskei Teshuvot 677:9, who writes on his own that one should burn the leftover wicks and may not simply throw them out.
- Mishna Brurah 677:18
- Bei’ur Halacha 677:4 s.v. HaTzarich writes that everyone agrees that if there is leftover oil in the container it is permitted. Not only according to Shulchan Aruch who holds that only the first half hour of oil is forbidden here is it permitted, but even according to the Bach that any oil that was placed in the cup to the burned is forbidden, here it is certainly permitted because it was never put in a candle to be burned. Berot Mayim 27, Kaf HaChaim 677:28, Ikrei HaDaat 35:32, Yalkut Yosef 677:14 agrees. [Sh”t Bet Av P”C 98 says that originally Peni Yehuda disagreed and then retracted.] See, however, Nitei Gavriel 57:1 who quotes some who disagree.
- Torat HaMoadim 5:26 permits the extra oil even if it was poured into the Chanukiya but was never lit. He cites Sh”t Mahari MeBruna 51, Sharei Knesset HaGedolah 673:8, Magen Avraham 673:8, Eliyah Raba 673:11, and Erech Hashulchan 672:5 as his support in opposition to the Olot Shabbat 672 who based on the Rama says one shouldn’t use oil that was put in the Chanukia and not lit. Chazon Ovadyah (Chanukah pg 160) agrees.
- Tur 677 in name of Maharam MeRotenburg says not to keep it until next Chanukah because someone may come to use the forbidden oil. Mishna Brurah 677:19 and Torat HaMoadim 5:27 agree. Halichot Yosef (pg 499) and Piskei Teshuvot 677:9, however, write that the Minhag Balza is to use it for burning the chametz.
- Shulchan Aruch 677:4. See Chazon Ovadyah (Chanukah pg 160-6) and Torat HaMoadim 5:28 at length.
- The Tur 677:4 writes that the prohibition of the leftover oil applies also to the leftover wicks. Kitzur S”A 139:20, Aruch Hashulchan 677:6, Piskei Teshuvot 677:9, and Nitei Gavriel 57:1 concur. Rav Hershel Schachter (Halachipedia Article 5773 #12) said that it is ineffective to make a stipulation for the wicks because they themselves are used for the mitzvah. See, however, Shevet HaKehati 1:200, who writes that since the wicks are burnt the same amount whether they burn for a short or long time, they may be used even if they go out within a half hour.