Summary of Re-cooking a precooked liquid:[12]

If is still Yad Soledes: Does not contain any cooking prohibition and thus is permitted according to all to cook by a fire [in ways explained in chapter 253] or to place in any pot of food that was heated on a fire and is now off the fire.

If is no longer Yad Soledes but is still hot enough to be eaten: The custom is to be lenient and allow it to be further warmed in the permissible ways explained in chapter 253.

If is cooled off to the point that it is no longer hot enough to eat: The custom is to be stringent that reheating contains a cooking prohibition [even after the fact and thus the food is forbidden to be eaten on Shabbos, Vetzaruch Iyun from 253]. If, however, a gentile heated it near a fire one may be lenient to eat it on Shabbos.

Q&A

What is the definition of Yad Soledes according to the Michaber?[13]

One should be stringent to consider 71 degrees Fahrenheit as Yad Soledes in this regard.

What is the definition of a liquid food?[14]

The food must be completely dry and not contain any moisture at all.[15] If a food has enough moisture to be Tofeiach Al Menas Lehatfiach, it receives the same law as a liquid.[16] This means that a solid food must be dry to the point that it’s moisture cannot wet one’s finger enough to make a further finger wet.[17] In such a case it is considered dry[18], even if it contains liquid inside of it, such as by a piece of meat. If any part of the solid contains this amount of moisture, then it has the same laws as a liquid even if majority of the solid is dry.[19] 

· Example: Spaghetti for soup may not be placed in a Keli Rishon if it has the amount of moisture stated above. [It may however be placed in a Keli Sheiyni and even have soup from a ladle taken from a Keli Rishon poured onto it in any case.[20]]

Does water have an Issur Bishul when it cools down?

Some Poskim[21] rule that according to all Poskim water that has completely cooled down to the point that all people would heat it, has a Biblical prohibition to heat it up even according to the Rama.

When is a liquid considered pre-cooked?[22]

When it has been previously cooked to the point of Yad Soledes. Others however hold it must be cooked until boiling point. If it has been cooked to less than Yad Soledes according to all there is a Biblical prohibition to further heat it on Shabbos even if it is still hot.

· If a liquid had been originally cooked to only Yad Soledes and is still warm may it be heated even past Yad Soledes, to boiling point?[23]

Yes, as once it has been cooked to Yad Soledes it is considered cooked.[24]  However there are Poskim[25] who rule one is to be stringent in this.

Should one ideally be stringent like the Michaber’s opinion which holds that so long as the liquid is below Yad Soledes it is forbidden to reheat it?

The M”B[26] writes, based on an implication from the Magen Avraham, that although we are accustomed to be lenient, nevertheless it is proper to be stringent like the Michaber. However, from the Alter Rebbe it is implied that we do not hold at all like the opinion of the Michaber. See Shabbos Kehalacha Vol. 1 p. 140 for a further analysis on this subject.

Does Lach have an Issur Bishul if it is Mitztamek Vera Lo? If the precooked liquid which has fully cooled down had cooked to the point of “condensing in a way damaging for the owner” is it still forbidden to reheat? [27]

Some Poskim[28] rule it does not have a prohibition of reheating even according to the stringent opinion if the food is Mitztamek Vera Lo. Others[29] however rule the same prohibition applies. Practically according to Admur it is forbidden.

Is fruit juice considered a liquid?[30]

Yes.

Is pure jam or paste, and the like of other pure fruit/vegetable pastes, considered like a liquid or solid?[31]

This matter is disputed amongst Poskim. The Igros Moshe rules that a liquid substance is determined by whether or not it can flow, and thus considers all pastes like a liquid[32]. However, Rav SZ”A rules that ketchup has the status of Yaveish being that it derives from tomato paste, and something which was originally a solid remains a solid even when its turned into a flowing paste.

· Is ketchup considered a liquid?[33]

This is subject to the above dispute and thus according to the Igros Moshe that a liquid substance is determined by whether or not it can flow, ketchup is a liquid[34]. Now, although ketchup is precooked, nevertheless since it is considered a liquid it thus contains the cooking restrictions being that it is cold.

· May one reheat a doughnut with jam inside?

If the jam is not made of pure fruit, then according to all it has the status of a liquid. If it is made from pure fruit, it is subject to the dispute mentioned above by ketchup.

If the liquid fully cooled down, and then became reheated[35] may one place it into a Keli Rishon?[36]

No. It only remains permitted to be further heated when it is still warm due to the heat of a Keli Rishon.[37]

May one use a wet spoon or ladle to remove soup from a pot that is off the fire?

No. See the laws of a Keli Rishon-Q&A there!

May one pour Keli Rishon water back into a Keli Rishon?

Only if it has yet to cool off, and the Keli Rishon is off the fire.

I poured 10 bowls of soup from the Keli Rishon soup pot which is now on the counter. By the time the tenth bowl was ready to be served, it had managed to become cold and I went ahead and poured it back into the Keli Rishon. What is the law of the Keli Rishon soup? May it be eaten on Shabbos? 

This matter requires further analysis.[38] Nonetheless, if this was done without consent of the parent of the home then seemingly at the very least it would remain permitted for all the other family members to eat on Shabbos.[39]

Question: [Motzei Shabbos, 26th Teves 5781]

I have a general question that comes up on Shabbos every so often that I would like to know. Am I allowed to pour directly from the hot water urn on Shabbos into a cup of hot water that I had previously taken out of that same urn? For example, if I made myself a Tea in a Keli Shelishi, and the Tea is no longer hot, can I add more hot water to it directly from the urn or must I use a Keli Sheiyni. Also, regarding soup, I have the same question, regarding if I can pour myself a second serving even though there still some broth left in my original bowl.

Answer:

Adding more water from the urn into a cup of plain hot/warm water: For Ashkenazim, it is permitted to add more hot water directly from the urn into a cup of water that one had removed from that urn, so long as the water that has remained in the cup is still somewhat warm to the point it would still be served as a warm drink. In such a case it is permitted to add more water even if one had poured the water into a second or third vessel. Furthermore, according to some Poskim, it is even permitted for Ashkenazim to add more water directly from the urn into the cup even if the water has cooled off completely, although one who is stringent is blessed. However, according to Sephardim, some Poskim rule that it is always forbidden to add anymore hot water directly from the urn into the cup even if the water is still Yad Soledes being that the water has been moved into a second vessel [Keli Sheiyni] and is thus considered as if it is cold according to their opinion. All the more so would it be forbidden for them to do so if the water is no longer Yad Soledes.

Adding more water from the urn into a cup of tea: Even according to Ashkenazim, it would be forbidden to add more hot water directly from the urn into the cup of tea, even if the water is still very hot, being that the tea itself has not yet been cooked, and was made using a Iruiy Keli Sheiyni or Keli Shelishi, and hence now when one comes to add more hot water to it directly from the urn this is considered Iruiy Keli Rishon which has ability to now cook the tea.  Now, even if one were to remove the teabag before adding more hot water to it, it would seem that it would still be forbidden to add hot water directly from the urn, being that the particles from the teabag that have now entered into the water and turned it into tea would still have a cooking prohibition. Vetzaruch Iyun.

Adding a second serving of soup: This follows the same ruling as adding more hot water directly from the urn into a cup of plain hot/warm water, and hence so long as the soup is still lukewarm, Ashkenazim may add a second serving directly into it, and even if the liquid has already fully cooled off, those Ashkenazim who are lenient have upon whom to rely, although one who is stringent to first wash and dry the bowl, or take a new bowl, is blessed. Sephardim, however, must take a new bowl, or wash and dry the previous bowl, in all cases.

Explanation: There is a debate between the Ashkenazi and Sephardi Poskim regarding if we apply the rule of cooking after cooking by liquids that are no longer Yad Soledes, with the Sephardim being stringent to consider it a Biblical prohibition, and the Ashkenazim being lenient so long as the liquid is not fully cool down. Now, regarding if liquid that is in a Keli Sheiyni is Halachically considered cold even though its temperature is still hot, some Poskim rule that it is to be treated as if it is cold. However, this stringency only applies for the Sephardim, while for Ashkenazim we view it as hot so long as the temperature has not cooled off. Now, regarding if Ashkenazim are stringent by fully cooled off liquid even by Iruiy Keli Rishon, or only by a Keli Rishon, this matter is debated amongst the Poskim and the Tzemach Tzedek and Ketzos Hashulchan conclude that one may be lenient although one who is stringent is blessed.

Sources: Regarding the dispute if we apply Bishul Achar Bishul Bedavar Lach, see: Admur 318:9; Michaber 318:4; Rama 318:15; Regarding the status of a Keli Sheiyni in this regard and if we consider is as cold, see: P”M 318 A”A 12; Biur Halacha 318 “Im”; Iglei Tal Bishul 11-8; Admur 253:14 [invalidates Mimeicham Limeicham only because of Michzi Kimivashel and not because of Bishul Achar Bishul]; Shabbos 38b; Shaareiy Tziyon 253:47; Piskeiy Teshuvos 318 footnote 227; Shabbos Kehalacha pages 365-356 [writes is permitted even for Sephardim!];  Regarding if we apply this stringency of Bishul Achar Bishul Bedavar Lach even by Iruiy Keli Rishon, see: Tzemach Tzedek Mishnayos Shabbos 3, brought in Ketzos Hashulchan ibid footnote 31; Ketzos Hashulchan 124:12; Shevisas Hashabbos Hakdama Mivashel 19; Or Letziyon 2:30-10; Beis Meir brought in Biur Halacha “Vehu” that those who are lenient do not need to be protested; Igros Moshe 4:74 Bishul 18; Piskeiy Teshuvos 318:51; See the following Poskim that one may always pour liquid of a Keli Rishon onto water, even if not cooked: Admur 318:20; Taz 318:18; Tosafos Pesachim 40b; Tur 318; Rashba, Ran and Rif on Shabbos 20a; Elya Raba Y.D. 68; Peri Megadim Yoreh Deah 68; Iglei Tal Ofeh 29; Tzemach Tzedek Mishnayos Shabbos 3:5, brought in Ketzos Hashulchan 124:12 footnote 31, and Tehilah Ledavid 318, in understanding of Michaber/Admur.