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A. Placing hot uncooked food on top of a hot pot so the uncooked food retain is heat:
A vessel which contains a hot food which is Yad Soledes is permitted to be placed on top of a pot which is insulated in clothes in order so it retain its heat and not get cold. This applies even if [the food in the upper pot] is not yet completely cooked in which case doing something to hasten its [further] cooking contains the cooking prohibition, nevertheless [here it is allowed to place it on top of another insulated pot which is not on a source of heat] being that it is impossible for it to become completely cooked through doing so and it cannot even further cook it, and it rather only retains its heat.
If the lower pot will heat the food to the point of Yad Soledes: However one may not place a vessel which has in it [food that] is not hot to the point of Yad Soledes on top of [another] pot which is so hot that it can heat the upper [pot] to the point that it will become Yad Soledes. The same law applies to placing [a pot] on top of a kettle which is this hot. However, this only applies when the [food in the] upper [pot] has not yet fully cooked in which case it contains the cooking [prohibition] even when hot.
B. Sealing the cover of a pot of uncooked food on Shabbos:
It is allowed to seal the lid [of the upper pot] in order to retain its heat.
C. May one re-insulate on Shabbos a pot that had been insulated before Shabbos?
If one wants to add [to the insulating material] on Shabbos other materials which do not add heat, he may do so. As well if one wants to remove all of the insulating material [placed before Shabbos] and place other material there in its place, whether the original insulation is hotter than the second one, or if the second insulation is hotter than the first [he may do so]. [However] this only applies if the food was fully cooked, however if it is not fully cooked and is insulated on top of a Kirah (that has in it coals) in the [permitted] ways to be explained [in Halacha 10], then it is forbidden to even add on to the cover, as this addition causes to speed up the cooking due to the coals.
Raw fruits: Nevertheless, on Shabbos itself it is forbidden to place these fruits in any area which the food can become heated to the point of Yad Soledes. [Furthermore] even to place it near an oven prior to it being turned on, is forbidden, unless it was completely cooked before Shabbos as explained in chapter 253 [Halacha 20]. [Furthermore] even if one insulated it from before Shabbos near a hot pot which was wrapped with clothes or with other items which do not add heat, and on Shabbos the covering [of the fruits] fell off, it is forbidden to replace it onto the fruits, if they are not yet completely cooked and the area there is Yad Soledes. Furthermore, it is also forbidden to add another clothing on Shabbos [to the insulation], being that this hastens it to finish cooking on Shabbos.
May one re-insulate a pot or add insulation to a pot that was insulated before Shabbos even if the food is not fully cooked?
If the pot is standing over a source of heat then it may only be reinsulated if the food is fully cooked, as by returning the insulation one speeds up the cooking. However if the pot is not on any source of heat, then it is always allowed to re-insulate or add more insulation on Shabbos, even if the food is not fully cooked, as this does not make it cook any further. [See footnote for opinion of M”B]
May one return a cover to a pot of non-fully cooked food that is off the fire?
May one place a cloth or the like on a pot of non-fully cooked food that is off the fire?
According to Admur it is permitted to place it on the side of the pot. According to the Mishneh Berurah it is forbidden.
 Admur 318:14; Michaber 318:6 [however does not mention uncooked food]; Taz 318:9; See also 257:8 that allows adding insulation so long as the pot is not on top of a constant heat source. However, see 254:4 which rules it is forbidden to place uncooked foods on top of an insulated pot; Tehila Ledavid 254:4 establishes the case there [254:4] to be referring to a pot that is on the fire and is insulated in a permitted way, such as with a board over the top of the pot, and the insulation is thus not touching the walls of the pot.
Other Opinions: See the following footnotes for other opinions that argue on the allowance of this law to uncooked foods.
 Tzaruch Iyun why Admur mentions that the lower pot is insulated? Perhaps this is because if the lower pot were not covered with insulation, it would be able to further heat, and further cook the upper pot and hence be forbidden. However, when there is a cloth insulation separating, it will never be able to further cook it.
 Admur ibid; Taz ibid; Elya Raba; brought in M”B 318:50
Other opinions: Many Poskim rule it is forbidden to place hot uncooked food on top of a hot pot due to the cooking prohibition. [Mahraiy Ben Chaviv; Bach; Olas Shabbos; Tosefes Shabbos 318; M”B ibid]
 Taz ibid
 Admur ibid; not mentioned in Taz
 Admur 318:15
 Tzaruch Iyun on the novelty in this additional statement.
 Admur 318:14; “It is allowed to seal the lid [of the upper pot] with dough in order to retain its heat if he has dough that was kneaded yesterday [and was designated for this purpose and is thus not Muktzah].”
 Admur 257:8
 Admur 254:4
 See 257:8; 318:14 which rules it is permitted to place uncooked foods that are Yad Soledes on top of an insulated pot; Tehila Ledavid 254:4 establishes the case here to be referring to a pot that is on the fire and is insulated in a permitted way, such as with a board over the top of the pot, and the insulation is thus not touching the walls of the pot.
 Shabbos Kehalacha Vol. 2 page 60; See Piskeiy Teshuvos 257:7 footnote 53 that discusses the dispute this matter
 Based on Admur 257:8; 318:14; M”A 257:; Taz 318:9; Peri Megadim; However see 254:4 which rules it is forbidden to place uncooked foods on top of an insulated pot; Tehila Ledavid 254:4 establishes the case there to be referring to a pot that is on the fire and is insulated in a permitted way, such as with a board over the top of the pot, and the insulation is thus not touching the walls of the pot.
Other opinions: Some Poskim rule it is forbidden to add or reinsulate whenever the food is not fully cooked even if it is not on a source of heat. The reason for this is because the insulation delays the cooling down of the food and during this time the food is able to cook more. [M”B in Biur Halacha 257:4 “Gorem Lah”; Beis Meir; Nehar Shalom; Mor Uketzia]
 Shabbos Kehalacha Vol. 1 p. 230-234
 Admur in 257:8 and 318:14; However, see 254:4 which rules it is forbidden to place uncooked foods on top of an insulated pot; Tehila Ledavid 254:4 establishes the case here to be referring to a pot that is on the fire and is insulated in a permitted way, such as with a board over the top of the pot, and the insulation is thus not touching the walls of the pot.
 Biur Halacha 257 “Lo Nisbashel”
 Shabbos Kehalacha Vol. 1 p. 230-234