Thermos Flask on Shabbos

Question: I forgot to put my Shabbos kettle on before Shabbos so took a thermos flask to my neighbours to fill up, though they thought it could be an issue of hatmana. Can one fill such a flask on Shabbos?

Answer: The Gemara (Shabbos 51a) teaches that the issur of hatmana, insulating foods on Shabbos, only applies to the pots in which the food was cooked, though not to any container into which the food is dispensed. As one knowingly cools the food by transferring the food, it is unlikely that one will then heat the food. Rashi explains that by transferring the food, one demonstrates that they don’t mind if the food loses a little bit of its heat. One would, therefore, be able to insulate the second container. Rambam (Shabbos 4:5) explains that chazal only prohibited insulating the food in the pot in which it was cooked. The Shulchan Aruch (OC 257:5) follows Rambam.

R’ Moshe Feinstein (Igros Moshe OC 1:95) writes that according to Rashi, one may not be allowed to transfer hot food into a thermos as one clearly does want to retain the heat. Nonetheless, as the Shulchan Aruch and others follow Rambam, one may use a thermos. Likewise, the Chazon Ish (Shabbos 37:32) and R’ Shlomo Zalman Auerbach (Minchas Shlomo 2:8:1) allow one to use a thermos flask writing that hatmana is specifically using towels and blankets, etc. to insulate. Accordingly, even Rashi would allow one to use a thermos flask.

R’ Ovadia Yosef (Yabia Omer OC 1:14) and R’ Eliezer Waldenberg (Tzitz Eliezer 11:29) quote R’ Shmuel Wosner who challenges the Chazon Ish, writing that he saw poskim who wouldn’t fill thermos flasks, though they both disagree with R’ Wosner’s challenge.

In conclusion, one may fill a thermos flask with hot water from a Shabbos kettle on Shabbos.

Sukka on Shemini Atzeres

Question: I know that some people eat in the sukka on Shemini Atzeres while others don’t. My parents aren’t religious and so I don’t have a specific custom. What should I do?

Answer: The Gemara (Sukka 47a) writes that there is a machlokes as to what one should do on Shemini Atzeres in chutz laaretz when there is a safek as to whether to treat it as the seventh or eighth day of Sukkos. The Gemara concludes that one should not shake the lulav and esrog though one should sit in the sukka without reciting the beracha, leishev basukka (See Rambam, Sukka 6:13; Rema OC 668:1; Yechave Daas 2:76). Tosafos explains that as people sometimes sit in a sukka during the year, it is less obvious as to why they are doing so than shaking one’s lulav and esrog.

R’ Tzadok Hakohen wrote a sefer (Meshiv Tzedek) defending the practice of not eating in one’s sukka on Shemini Atzeres. Likewise, the Aruch Hashulchan (OC 668:4) justifies this minhag explaining that Tosafos’ rationale wouldn’t apply in particularly cold climates when people would only sit in a sukka for the mitzva. R’ Moshe Sternbuch (Moadim Uzemanim 1:92) challenges this, however, as most of the rishonim lived in Europe and Russia and they never suggested that people should be exempt because of this.

There is a machlokes however, as to whether one should sleep in the sukka on Shemini Atzeres or not. While the Vilna Gaon (Maaseh Rav 222) writes that one should, the Mishna Berura (668:6) concludes that the minhag is not to.

In conclusion, one should eat in a sukka on Shemini Atzeres without reciting the beracha, leishev basukka, unless one has a specific minhag not to do so.

Build Sukka After Yom Kippur

Question: I heard that one is supposed to build their sukka after Yom Kippur though I don’t always have the strength to do so after fasting. How important is it?

Answer: The Rema (OC 624:5; 625:1) writes that it is commendable to begin building one’s sukka straight after Yom Kippur so that one goes from one mitzva to another. The Pri Megadim (Mishbetsos Zahav 624:3) and Mishna Berura (624:19) add that one should complete assembling it the following day.

The Kaf Hachaim (OC 625:11) stresses the importance of building one’s sukka oneself rather than having another do so on their behalf. One should at least place a little sechach on by themselves.

The Pri Megadim (Eshel Avraham 25:1) questions whether one who is unable to build the sukka oneself immediately after Yom Kippur should rather appoint somebody else to do so on their behalf. On the one hand, it is always preferable to do the mitzva at the first opportunity, though on the other hand, it is preferable to perform mitzvos oneself rather than by appointing others to do so on their behalf. The Sdei Chemed (Mem:58) and R’ Shmuel Wosner (Shevet Halevi 4:66) write that in such scenarios, one should rather preferable to perform the mitzva oneself, even if it isn’t the ideal time.

The Aruch Hashulchan (OC 624:7) writes that if one cannot build their sukka on motzaei Yom Kippur, they should learn the halachos of building a sukka during that time instead (See Kaf Hachaim OC 624:35).

Nonetheless, the Shaarei Teshuva (625:1) argues that it is best to begin building one’s sukka before Yom Kippur (See Avnei Yashpei 8:110:3).

In conclusion, one should try one’s utmost to at least place some sechach on one’s sukka on motzaei Yom Kippur. One who cannot do so should learn some of the halachos then instead.