Sometimes one removes a pot from the plata on Shabbat in order to remove food, and then wishes to return it to the plata. May one take this action, known as haĥzara? Once again there is disagreement among the poskim.
According to those who are lenient and allow placing food on a plata or blekh on Shabbat (maintaining that this does not resemble cooking, as explained in the previous section), one may certainly return a pot to the plata if it had already been there on Shabbat, as long as the food is fully cooked and the fire is covered. (If the food is not fully cooked, one violates the Torah prohibition of cooking. As long as the fire is covered, there is no concern that he will turn up the flame.)
Those who are concerned that placing cooked foods on the plata on Shabbat resembles cooking, and thus forbid doing so, view returning food to the plata differently. Since the food was already on the plata before Shabbat, returning it does not resemble cooking. Therefore, as long as it is clear that one is simply returning the pot to the plata, and not placing it there for the first time on Shabbat, he may do so. In order to make it clear that this is haĥzara and not initial placement, three conditions must be met, le-khatĥila: 1) the pot must not be placed on the floor; 2) the person removing it must have in mind that he will return the pot to the plata; 3) the person must keep hold of the pot until he returns it to the plata. Be-di’avad, if there is a great need to return the pot to the plata because that is the only way there will be hot food at the meal, then even if these three conditions are not met, one may return the food to the plata. This is because the food is still, in fact, being returned to the plata, and not being placed there for the first time.
. The laws of haĥzara apply specifically to a kira, and the leniency is on condition that when one returns the pot, he places it on top of the kira and not inside it. (If he wishes to place food there on Shabbat, there must be some additional separation between the kira and the pot.) For those who maintain that placing a pot on the plata is forbidden because it resembles cooking, haĥzara may still be permitted, since this would be the equivalent of placing an item on a kira and not inside it. However, one must ensure that certain conditions are met. SA 253:2 mentions only the first condition, that the pot is not placed on the ground. Some maintain that placing the pot on the counter is the equivalent of putting it on the ground, since the counter is attached to the ground (Or Le-Tziyon 2:17:6; Menuĥat Ahava 1:3:5). Others maintain that the counter is different from the ground, because it is normal to briefly place a pot on the counter and then return it to the stove (Az Nidberu 8:17). The custom is to be lenient. One who wishes to be stringent should place the pot on a towel instead of directly on the counter (see SSK, ch. 1 n. 61).Two additional conditions are mentioned by Rema. If one places the pot on a bench, according to Rema, as long as he keeps hold of the pot he may replace it. But if he places it on the ground, it does not help to keep hold of it; he must hold it so that only part is on the ground and part remains in the air (Shvut Yitzĥak vol. 2, p. 161, based on Maharam Schick §117). According to Igrot Moshe, OĤ 4:74, Bishul §33, if one keeps hold of the pot, that is enough to render haĥzara permissible, even if it was placed on the ground. In any case, be-di’avad if one did not meet this condition, Rema is more lenient. According to SA, the first condition is absolute; if one placed the pot on the ground, he may not return it. According to Rema, however, be-di’avad he may return it even if it was placed on the ground. I did not record SA’s opinion in the main text because some maintain that it is always permitted to heat cooked food on a plata or blekh. Therefore, even those who are stringent can be lenient here and follow Rema. All of this of course assumes that there is no problem of actually cooking when one returns the pot to the heat source. Regarding liquids, see sections 5-6 above. According to SA, one may return liquids to the plata only if they have not cooled to below yad soledet bo, while according to Rema 318:16, as long as they retain some warmth this is permitted. However, some are more stringent and maintain that one may not return a pot to the plata itself because a plata is considered the equivalent of a kira whose coals have not been covered. This is the opinion of Ĥazon Ish, OĤ 37:9, 10 and R. Qafiĥ. However, since this law is rabbinic and the vast majority of poskim are lenient, I did not present this opinion in the main text.