Shiur #05: Easily Cookable Items
LAWS OF SHABBAT: COOKING
Refuah Shleima to Aaron Meir Ben Silah
Shiur #05: Easily Cookable Items
What Can Be Cooked in a Keli Sheini?
A number of Talmudic passages indicate that not every food is equal when it comes to the vessels in which they may be cooked; some are kallei bishul (easily cooked items), which get cooked even in a keli sheini (secondary vessel).
The mishna (145b) says:
Whatever was put into hot water before Shabbat may be steeped in hot water on Shabbat; but whatever was not put into hot water before Shabbat may be rinsed with hot water on Shabbat, except for kippers and Spanish mackerel, because their rinsing concludes their preparation.
We see from this mishna that kippers and Spanish mackerel, foods that are easily cooked, cant even be rinsed (with hot water) on Shabbat.
Tosafot (39a, s.v. Kol) cite an argument: is the rinsing mentioned here referring to irui from a keli rishon (primary vessel) or a keli sheini? According to the view that this is the latter, we can clearly see an established law that there are foods that can be cooked even in a keli sheini.
We can find an additional source in the words of the Gemara (42b) that raises the possibility that salt can be cooked in a keli sheini. The Rishonim do not adopt this ruling, but we may ask why: it may be that the reason is that nothing could possibly be cooked in a keli sheini; however it may be that specifically salt does not cook in a keli sheini, but other items do.
An Additional Problem: The Appearance of Cooking
An additional reason to rule stringently about a keli sheini comes from the words of Tosafot (loc. cit.); in their view, even though a keli sheini does not cook anything, there is a rabbinical prohibition to put uncooked items in a keli sheini, since this is mechzi ke-mevashel (has the appearance of bishul).
The Rishonim argue about whether this is indeed the halakha.
Ramban and Ran: No Prohibition of Bishul in a Keli Sheini
1. The Ran (20a, Rif, s.v. U-miha shaminan) writes that even a keli rishon does not always cook:
Even though a keli rishon cooks, this refers specifically to food items that are easy to cook, such as water, oil, spices and the like; however, foods that are difficult to cook cannot be cooked in it, just as we conclude concerning salt to be lenient. Nevertheless, since we are not experts in the nature of these foods, we forbid putting anything on Shabbat into a keli sheini, aside from that which is explicitly allowed in the Gemara.
In his view, there are food items that cannot be cooked even in a keli rishon, however since we are not experts in the culinary arts and techniques, we are stringent about a keli rishon for everything. However, the Ran indicates that the doubt is about a keli rishon only, while for a keli sheini there is certainly no prohibition of bishul at all, and there is no concern of kallei bishul.
The Rambam does not talk about the issue; however, his language (22:6) indicates that he is lenient:
If one pours a food from a pot to a bowl, even though it is boiling in the bowl, it is permitted to add spices to the bowl, because a keli sheini does not cook.
Though the Rambam talks about spices, he gives a general justification: a keli sheini does not cook, and this implies that a keli sheini does not cook at all. It may be that this approach is based on the understanding that the rule a keli sheini does not cook is not pragmatic but halakhic a keli sheini is not defined as a heat source that has a prohibition of bishul, and naturally one is allowed to cook in the keli sheini even those food items that may end up getting cooked in it.
Yereim: One May Not Put Anything Uncooked in a Secondary Vessel
2. The Yereim (ch. 274, 134a) offers a different approach. In his view, since there are foods that are easily cooked, and we cannot identify them, we may not put anything in a keli that is yad soledet bo (scalding), despite the fact that he allows putting salt even in a keli rishon:
Therefore, a person should be careful not to put anything in a keli sheini, or even in a keli shelishi (tertiary vessel) that is yad soledet bo, because we are not experts in the definition of soft and hard foods to know whether they can be cooked in a keli sheini.
The view of the Yereim is consistent with the view that the determination that a keli sheini does not cook is a pragmatic assessment, not merely a halakhic one, and as long as we do not know with certainty that a food will not cook if placed in a keli sheini, we must be concerned that it may belong to the category of kallei bishul.
The Leniency of the Shulchan Arukh
The words of the Shulchan Arukh (318:5) indicate that he is lenient about the law of a keli sheini, at least in reference to bishul achar afiya (cooking after baking): 
There is one who says that if one cooks that which has previously been baked or fried, this is considered cooking, and thus it would be forbidden to put bread even in a keli sheini that is yad soledet bo; however, there are those who allow it.
The Rema (ad loc.) explains that the language of there are those who allow it is meant to be understood as a leniency specifically for a keli sheini. In other words, essentially there exists a prohibition of cooking after baking, but there is no prohibition to do so in a keli sheini. This is how the Mishna Berura (43) explains: This view holds that a keli sheini cannot cook anything.
It should be noted that there are those who believe that the Shulchan Arukh is lenient even for a keli rishon, because there is no prohibition on cooking after an item has been baked (we well get to this in a later shiur) and according to this, he is not speaking of a keli sheini at all.
The Remas Stringency
However, the Rema himself writes that we follow the view of the one who says, and we do not put bread even into a keli sheini.
It is our preferable custom to be careful not to put bread even into a keli sheini, as long as it is yad soledet bo.
The Mishna Berura (42) explains that according to this view we should be stringent about a keli sheini, even for other foods, following the Yereim. This, according to him, is the law for Ashkenazim:
This view holds that there are items that can be cooked in a keli sheini because they are soft, and we are not experts. Therefore, he goes further, forbidding putting baked bread, which is soft, even in a keli sheini. Similarly, according to this view, we should be stringent about other food items even in a keli sheini.
The Middle View
3. There are Acharonim who espouse a middle view: it is permissible to cook anything in a keli sheini, excluding foods that appear to be kallei bishul. This is what the Shulchan Arukh (318:25, 44) and the Torat Shabbat (318:16) believe: a keli sheini does not cook, and one need not be concerned that everything might fall into the category of kallei bishul. However, if we observe that a certain food is easily cookable, one must treat it stringently. As the Arukh Ha-shulchan writes (ad loc. 28) about tea leaves:
The plant called tea, over which hot water is poured, is known to be easily cooked, and even in a keli sheini it will become cooked, as our own eyes have seen, so one who pours hot water over them on Shabbat, even using a keli sheini, is liable to bring a sin-offering, and many have stumbled in this
This is also what the Chazon Ish writes (52:18-19), that it is possible that the prohibition is specific to baked goods, as once a food has been baked, it may more easily be cooked. The same would apply to eggs or other foods that, as we may observe, are easily cooked. When it comes to all other items, it is permissible to put them in a keli sheini, and one need not be concerned about this in general.
Practical Law and Custom
In fact, the Ashkenazic custom is to follow the Mishna Berura, and Ashkenazim do not put anything that is not cooked in a keli sheini, due to the concern of kallei bishul. (Even the Chazon Ish, who, as mentioned above, supports being lenient about this by the letter of the law, notes that the custom forbids it). This also appears in Shemirat Shabbat Ke-hilkhata (1:53). Among the Sefardic authorities, there are those who write that the custom is to be lenient (Tevuot Shemesh by Rav Shalom Messas, ch. 30, ch. 66; Tefilla Le-Moshe vol. I, ch. 33), and there are those who forbid it (Ben Ish Chai, Year 2, Bo 6; Rav Mordekhai Eliyahu in his notes to Kitzur Shulchan Arukh, 80:3). Nevertheless, it makes sense to see the concern about a keli sheini as a rabbinical prohibition only.
Water, Oil and Spices
What falls into the category of spices?
The Taz (318:8, 14) writes that it is forbidden to put onions in a keli sheini that is yad soledet bo, since they are sharp and cook quickly. On the other hand, the Magen Avraham (15) writes that this is allowed because this is analogous to spices, a view confirmed by Shulchan Arukh Ha-Rav (318:11) and Arukh Ha-shulchan (318:44).
On the other hand, the Mishna Berura (45) is stringent about this, explaining (Shaar Ha-tziyun 69) that when the Magen Avraham was lenient he was only explaining that according to the views that we are not concerned about bishul in a keli sheini, but only about it being mechzi ke-maveshel, there is no prohibition for onions; however, according to our view, which is concerned about actual bishul too, following the path of the Yereim, we may not put onions in a keli sheini. Rav Moshe Feinstein writes (OC Part 4, 74, Bishul, 18) that an onion is not like spices, and one should be stringent about it, because it is fit to be eaten on its own, as opposed to spices; this is evidenced by the law that onions must be tithed even though spices are exempt from tithing.
Rav Auerbach: Modern Spices are Problematic
Rav Auerbach is cited (Shemirat Shabbat Ke-hilkhata ch. 1, n. 152) as claiming that our modern processed spices cannot be equated with those in the Gemara:
It does not make sense that these are the same spices as those that we use in order to season our food, as [the latter] are extremely fine; all the more so will they be cooked in a keli sheini!
Rav Feinstein and Rav Elyashiv: Modern Spices are the Same
However, Rav Moshe Feinstein (loc. cit.) writes that cocoa and coffee are included in the category of spices, and it is permissible to put them in a keli sheini, even if they have not been cooked and even if they are finely ground. In his view, it would appear that even other ground spices may be put in a keli sheini. This is also what is cited in the name of Rav Elyashiv (Shevut Yitzchak, Bishul, 24:3), that spices are not easily cooked, and it does not matter that they have been finely ground:
I have heard from Rav Y.S. Elyashiv that a substance that is hard in its nature, even though it is ground and made fine, does not become easily cookable, since it is not made soft.
The Chazon Ish (52:19) allows putting lemons into a keli sheini because it falls into the category of spices, while Rav Auerbach (Shemirat Shabbat Ke-hilkhata, ch. 1, n. 150) writes that one should not be lenient about this, and Rav Feinstein (loc. cit.) writes that one should be stringent as well.
One should add that the prohibition in a keli sheini applies to foods that have never been cooked, but a liquid that has been boiled and cooled may be put in it (Mishna Berura 318:23). Indeed, we are stringent to say that concerning a liquid food (davar lach) there is a prohibition of cooking, as we shall see in a future shiur, but since this law is the subject of a dispute of Rishonim, and furthermore most Rishonim believe that a keli sheini does not cook, these two can together form a good basis for leniency.
Translated by Rav Yoseif Bloch
 This is based on the assumption that the prohibition is one of bishul, as Rashi (39a, s.v. She-hadachato), the Rambam (9:2) and the Beiur Halakha (318:4, s.v. Ve-hadachatan) rule. It is also possible that this is forbidden because of the eclectic melakha of makkeh ba-pattish, striking the final hammer blow, which includes various action that complete a process. (This follows the view of the Peri Megadim, cited by Beiur Halakha loc. cit.).
 As for salt, the Ran himself in his Chiddushim (42b) writes that salt can be cooked in a keli sheini. The logic is that salt does not require true bishul; rather, making it lukewarm is equivalent to cooking it, and therefore it does cook in a keli sheini. This appears to be how the Ran explains the law of Spanish mackerel. In light of this, something that requires actual bishul cannot be cooked in a keli sheini, and only concerning kippers and Spanish mackerel is there any reason to forbid it.
 This is the generally accepted understand of his view, that the halakha follow the latter view, and this is what Rav Ovadya Yosef writes (Yechaveh Daat, Vol. II, ch. 44).
 In truth, if we are concerned about kallei bishul, it may be that this is a biblical doubt. However, since many are lenient about this, it appears that the ban is only a stringent view, and this issue should not go beyond the rabbinical level (and naturally one may be lenient about it in cases of doubt). However, when it comes to things that may be observed to be kallei bishul, there is a reason to be concerned about the doubt of a Torah prohibition.
 According to Shulchan Arukh Ha-Rav (318:12) and other Acharonim, all liquids have the status of water and oil, and there is no prohibition to put them in a keli sheini. However, in the words of the Mishna Berura (318:39), it appears that one should be lenient only for water and oil (as he only allows one to put tea essence and milk in a keli sheini because they have already been boiled).
 As we mentioned above, the view of Tosafot is that even when a keli sheini does not cook, there is a rabbinical prohibition to put uncooked things in a keli sheini, because it is mechzi ke-mavashel. Tosafots words are adopted by the Mishna Berura (318:34) and other Acharonim. According to this, why does the Gemara allow putting certain things in a keli sheini? Concerning spices, Tosafot explain themselves that putting them in does not involve an issue of the appearance of bishul, since they come only to impart taste to the food. Concerning water and other liquids, the Peri Megadim explains (Eshel Avraham 318:32) that since they are mixed well in the food, this does not look like cooking. The problem of mechzi ke-mevashel relates, according to him, only to solid foods soaked in a liquid contained in a keli sheini, not foods that are mixed in it.
 We may justify this lenient view, by noting that, throughout the Talmud, we find that spices are referred to as ground, for example in Beitza (14a), crushed spices etc. If so, the fact that the Mishna allows putting spices in a keli sheini without any limitations apparently indicates that this is allowed for fine spices as well.