Siman 95

The halakha was decided in the Gemara (Chullin 111b) that fish that were placed on a plate may be eaten with kutach because it is a case of giving flavor from a giver of flavor. The explanation of the matter: hot roasted fish that were placed into a plate in which meat had been eaten, it is permitted to eat the fish with kutach, which is a dairy food. We do not say that the fish contain the flavor of meat which they absorbed from the plate, because this is not a complete flavor; for certainly if they were cooked together with the meat it would be forbidden to eat them with kutach, and likewise to eat hot milk in a meat plate, because it is a first flavor and is like actual meat. However, this plate itself is not meat, but rather the meat gave flavor into it, and the plate gave flavor into the fish, and it is two flavors of a permitted substance and the flavor is weakened. Therefore, it is permitted to eat them with kutach. There is no difference whether the fish and the plate are both hot, or whether one is hot and the other is cold, and all the more so when both are cold (and see there in Tosafot s.v. Halakha). Regarding that which concerns danger, it will be explained in siman 116 with the help of Heaven.

And this is the foundation of the law of nat bar nat, for in any such case where the food absorbed from a meat vessel that was used within the day, it is permitted to eat this food with milk, because the flavor was weakened and it became nat bar nat, and likewise the reverse. And this law applies only to meat with milk or milk with meat, for since the second flavor is still of a permitted substance and it was weakened to such an extent, it is not considered significant enough to forbid. However, regarding a forbidden substance, wherever there is flavor it forbids forever (Ran on Chullin 41a, s.v. dagim), meaning, for example, a pot in which a forbidden substance was cooked, and afterwards water was cooked in it, and some of the water was put into food, sixty times the volume of all the water is required, for we consider the water like the forbidden substance itself even though it is a second flavor, and so on forever. And one should not ask: in any case the flavor of the forbidden substance was weakened just as the flavor of the meat was weakened, and granted, according to the one who holds that a piece becomes a carcass regarding other forbidden substances it is understood, but according to the one who does not hold so, why do we not permit the food that was cooked with this water? What difference is there to me between the weakening of a meat flavor or the weakening of a forbidden flavor? For certainly they are not comparable, for that which we permit nat bar nat is not because we hold that the first flavor does not spread to the third, for if we were to say so, certainly even regarding other forbidden substances it would be permitted in such a case according to the one who does not hold that a piece becomes a carcass. Rather, we permit it when the second flavor was of a permitted substance because it lacks the significance that such a weak flavor, which is of a permitted substance, should forbid; but regarding the flavor of a forbidden substance, this does not apply (I learned this from the words of the Ran, of blessed memory, see there). And see what I wrote in siman 94, section 23.

And know that even regarding nat bar nat of a permitted substance, we only say this when the first taste was in a vessel and the second in the food, such as with fish that were placed on a plate as we have written. However, when even the first taste was in food, we do not permit nat bar nat. For example, if some hot food was placed on hot meat, and afterwards they placed the fish on this hot food, it is forbidden to eat the fish with kutach. For so ruled the Rishonim, the author of Sefer HaTerumah (siman 61) and the author of the Sha'arim, siman 60 [cited in the Pri Megadim in the Mishbetzot Zahav, subsection 1, and in the Havat Da'at (subsection 1)], that specifically when the first taste is in a vessel and the second is in food, the taste is weakened; but when the first is in food, it is like the substance itself [ibid.]. And there is one who wishes to disagree with this [see Pitchei Teshuvah (subsection 1)], but there is no reason in his words, for it is certainly so, based on the foundation that we wrote in the previous section, that we only say the taste does not spread because of its weakness, and this applies when the first taste is from a vessel and not from food.

And also, even when the first taste was in a vessel, we do not say "taste from taste" at the time of cooking. For example, if milk fell onto a pot in which fish are being cooked, opposite the broth, and afterwards they cooked the fish with meat, the fish are forbidden if there was not sixty times against the milk. And we do not say, behold the milk gave taste to the pot and the pot to the fish and it is literally "taste from taste," for since it fell at the time of cooking and the cooking permeates the entire pot, it is as if they are all tied to one another, and it is as if the milk fell upon the fish [Chavat Da'at, subsection 1]. And there is one who says that even at the time of cooking we say "taste from taste" [Pitchei Teshuva in the name of Beit Ephraim], and it appears that the primary view is like the first opinion and one should not be lenient in this. [And it is possible that it depends on the opinions that will be explained regarding whether there is a distinction between if they were brought up or if they were cooked, and it requires further study, and look closely]:

Our teachers, the Rishonim, have three approaches regarding the law of nat bar nat. Some say there is no difference between whether the fish were placed hot onto a meat plate or whether they were cooked in the plate or roasted in the plate; in all of them, it is permitted to eat the fish with kutach because it is nat bar nat. This is the opinion of Rabbeinu Tam and Rabbeinu Yitzchak the Elder (Hagahot Ashri Chullin chapter 8, siman 29), and it is similarly explained from the commentary of Rashi (Chullin 111b), and it is also implied from the Rambam chapter 9 (Rambam, Laws of Forbidden Foods 9:23), see there. And some say specifically "placed onto" but not "cooked in," for when they were placed onto a hot plate, the fish only absorbed the thickness of a peel, and the absorption is minimal; in this case they permitted nat bar nat. However, when they were cooked in the plate and all the meat flavor that was in the pot was absorbed, they did not permit nat bar nat in this case, for this is as if they were cooked with actual meat. This is the opinion of Riban in the name of Rashi, of blessed memory, which the Tosafot and the Rosh cited there. And some say that if they were cooked it is permitted, but if they were roasted it is forbidden; for in the case of cooked there are three flavors: the meat in the plate, the plate in the water, and the water in the fish. And even though it could be said that the discharge went from the plate itself to the fish, nevertheless, we are witnesses that the majority of the discharge went into the water. But in the case of roasted, since the discharge goes from the plate itself to the fish, it is like a first flavor and is forbidden. This is the opinion of Sefer HaTerumah (siman 61), the Semag (Prohibitions 140-141), and the Semak (siman 213), and to this the Rosh agreed (Kol HaBasar, siman 29):

Our teacher, the Beit Yosef, decided according to the first opinion that it is permitted in every case, as he wrote in section 1: Fish that were cooked or roasted in a meat pot that was washed well so that no fat is clinging to it, it is permitted to eat them with kutach, because it is a case of nat bar nat of a permitted substance. And if it was not washed well, if there is more than one-sixtieth of the substance on the surface of the pot relative to the fish, it is forbidden to eat them with kutach. An egg that was cooked in water in a dairy pot, it is permitted to place it inside a chicken even ab initio, but if it was cooked in a pot with meat, even in its shell, it is forbidden to eat it with kutach. Thus far his words. And the pots were ben yomo, and it is a simple matter, and therefore he did not need to specify, and he already explained this in siman 93, that in a pot that is not bat yoma, even if one cooked milk itself it is permitted, and all the more so the fish that were cooked in it, that it is permitted to eat them with kutach.

He was precise to write "well-washed so that no fat is clinging to it," and it is certainly obvious that since it is well-washed, no fat is clinging to it. It appears to me that he comes to teach us that the concern is only regarding the clinging of fat, such as if they cooked only meat alone in the pot without a dish, and when there remained around the pot from the inside, the fat of the meat remained, and it is like the substance of the meat and not like its flavor. However, if they cooked in it a dish of types of groats or potatoes or of rice and millet or of dough, and they also put meat in it as is our way of cooking, where the meat is a small amount compared to the dish, even if the pot is not well-washed we have no concern with it. For that which is around the pot from the inside is a dish that has the flavor of meat, and it is only the flavor of meat and not meat itself. And even according to what we wrote in section 3, that when the first flavor is in a food we do not rule with the law of nat bar nat, nevertheless here also the primary flavor is in the pot, and we are not concerned with the small amount of sauce around the pot that has the flavor of meat, and we judge this with the law of nat bar nat [so it appears to me].

The acharonim wrote that his intention is not that we require knowing that it was washed well, for even in an ordinary case we say that presumably it was washed well, as is the way of householders who clean the pots after eating; and he only came to exclude a case where we know that it was not washed well [Shach, subsection 1]. And there is one who disagrees on this, but it is not the primary view, for even if we say that it is not rinsed well, nevertheless, it is presumably clean of fat. And know that the author of the Issur V'Heter HaAruch wrote [Rule 33 (Law 2)] that in an ordinary vessel there is sixty in the cooked food against the dirt upon it. And know that this requirement of sixty in the fish against the substance on the surface of the pot applies when they were roasted, but when they were cooked, it is sufficient that there be sixty in the fish together with the water in which they were cooked, for the flavor spreads equally into the fish and the water [Pri Megadim (Siftei Da'at), subsection 1].

And that which he wrote, that an egg that was cooked in a milky pot is permitted to be placed inside a chicken, it is not specifically a chicken, for the law is the same for the meat of an animal; for there is no difference in the law of nat bar nat between the meat of an animal, which is prohibited with milk from the Torah, and the meat of a bird, which is rabbinic. And even if the egg was peeled, provided that the pot was clean. Rather, it is because the source of this law is from the Responsa of the Rashba (Part 1, Siman 516), and there the incident was such, and it is his way to bring the wording of the source. And that which he wrote, that when it was cooked with meat it is prohibited to eat it with kutach even if it was cooked in its shell, the reason is simple: for the shell of the egg is perforated and the flavor enters it. And the proof for this is that when one cooks it in dye-water, the dye will also be on the egg itself [Taz, subsection 2]. And one cannot say the reason is because it exudes through the shell, for if so, we would judge it with the law of nat bar nat, as we would consider the shell like a vessel; rather, certainly in the shell itself there are perforations [Pri Megadim, ibid.], and not necessarily actual perforations, but rather like thin perforations that cannot be perceived by the sense of sight; however, in any case, it is not similar to a vessel [ibid.]:

From the language of the Gemara it appears explicitly that in the matter of nat bar nat there is that which is forbidden lechatchila and only permitted b'dieved, and there is that which is permitted lechatchila. Specifically, to place the fish in a meat bowl in order to eat them with kutach is forbidden lechatchila, and therefore the Shas says "fish that were brought up in a bowl," meaning b'dieved when they were brought up; but once they were brought up, it is permitted to eat them with kutach lechatchila, and therefore the Shas says "it is permitted to eat them with kutach," and "permitted" means lechatchila, see there. And there is one who says that if one acted lechatchila to place the fish in a meat bowl in order to eat them with kutach, we penalize him so that he may not eat them with kutach [Pri Chadash subsection 1 in the name of Minchat Kohen], and there is one who disagrees in this since it is merely a distancing [Pri Chadash], and it appears like the first opinion so as not to become accustomed to a prohibition.

Our teacher, the Rema, wrote in section 2, and this is his wording: There are those who are stringent regarding roasting and cooking to prohibit nat bar nat, and the custom is to prohibit it lekhatchila, but bediavad it is permitted in every case, and specifically to eat with milk and meat itself, but to place them in their vessel is permitted lekhatchila, and so they practiced. And likewise if they were not cooked or roasted initially, but only were placed in a meat vessel, it is permitted to eat them with milk itself, and likewise the reverse, and likewise if the vessel in which they were cooked or roasted was l'fagam, such that it was not ben yomo, we practice permissibility lekhatchila to eat them with the second species. Thus far his words.

The "there are those who are stringent" refers to the second opinion in section 5, and for the law he also agrees with the first opinion, as this is the opinion of most poskim, except that they were accustomed to be stringent like the second opinion lechatchila, but bedieved it is permitted; that is to say, lechatchila one should not eat them in kutach, but bedieved when they were placed in kutach it is permitted to eat and we rely on the first opinion, and this is not like the lechatchila and bedieved in section 10, see there. And there is one who wishes to say that if they were roasted even bedieved it is forbidden [Shach, subsection 4 in the name of the Rashal], and this is according to the third opinion that we brought in section 5, but from our teacher, the Rema, it does not imply so, and especially since our teacher, the Beit Yosef, decided the halacha according to the first opinion. And know that there is one who wishes to say that according to the second opinion if the fish and the bowl are both hot their law is like those that were cooked and it is forbidden, and it is only permitted when one is hot and one is cold [Taz, subsection 3], but it does not imply so from all the words of the Rishonim. And it is true that it somewhat implies so from the wording of the Tur who wrote boiling fish etc. in a cold bowl etc., see there, however even he does not intend this specifically, and he said it as a greater novelty as the commentators wrote [see Bach, and so it implies from the Beit Yosef], and the proof for this is that if it were not so, why did he conclude "but if they were cooked etc.", let him say "but if both are hot," rather it is certain that there is no distinction in this. [And also the Gaon Rabbi Baruch Frankel disputes him in the margin, and the Tosafot who wrote so (Chullin 111b) wrote it as a greater novelty for Rav that even in such a case he forbids as is proven from their words, and also the Rosh intends this, and it appears to me that the Tur was drawn after their wording, and there is no need for the forced explanation of the Bach, and look closely, and also the Shach subsection 6 contradicts his words in siman 94 subsection 33 as the Pleiti wrote (subsection 3)]:

And that which he wrote, that to place them in their vessel is permitted ab initio, meaning to place something that was cooked in a milk vessel into a vessel of that day's use in which meat was cooked, even when it is boiling, for this is two flavors by way of vessels. And some say that only to place them is permitted, but to pour by way of pouring from a vessel in which milk was cooked, and now they cooked some item in it, to pour the cooked food into a meat vessel of that day's use is forbidden ab initio, and perhaps even ex post facto, as he wrote below in section 3. This is his wording: And if one poured from a first vessel of meat onto a milk vessel, its law is like a first vessel and it forbids if it was of that day's use. Thus far his words. [Pri Chadash, subsection 6]. However, his words require further study as will be explained there (section 22) with the help of Heaven [ibid.], and many of the great authorities agreed that it is permitted [Shach, subsection 5, in the name of the Issur V'Heter HaAruch (rule 34, law 5), and in the name of the Mas'at Binyamin], and the reason he permitted placing them in their vessel is that in this we rely on the first opinion [Taz, subsection 5].

And that which he wrote, that if they were not cooked or roasted initially but only were placed in a vessel of meat, it is permitted to eat them with milk itself, and similarly the reverse. Thus far his words. This is simple, because in the case of being placed in a vessel it is permitted according to all opinions, and we have already written that the later authorities are stringent that when both are hot it is like they were cooked, and in my humble opinion this does not seem correct as I wrote in section 12. And that which he wrote, that if the vessel in which it was cooked or roasted was not ben yomo, we practice leniency ab initio to eat them with the second species. Thus far his words. The reason is also simple, and it has already been explained in a similar case in siman 93 (section 2), see there.

He further wrote: And all this is when the food is not a sharp thing, but if it were a sharp thing, such as if they cooked sharp things in a vessel of meat even if it is not ben yomo, or if they crushed spices in a mortar of meat, if one ate them with milk it is forbidden even ex post facto until there is sixty against the meat absorbed in them; nevertheless, a food is not called a sharp thing because of a few spices in it, only if all of it is a sharp thing, and its majority is like its entirety, and see further in siman 96 (Shulchan Aruch Yoreh Deah 96) (Shulchan Aruch section 1). Thus far his words. For with a sharp thing we do not say nat bar nat, because its sharpness makes it as if the forbidden substance is present, and also with a sharp thing "not ben yomo" is not applicable, for sharpness sweetens it for improvement as if it were ben yomo, as will be explained in siman 96 (section 4), and there it will be explained (seifim 13-14) what is called a sharp thing, and we have only the ruling of our teacher, the Rema; however, in a place where there is a doubt if this is a sharp thing or not, one should be lenient [see Pitchei Teshuvah subsection 4], and in siman 96 more will be explained regarding this with the help of Heaven.

When the discharges of meat vessels and milk vessels that are ben yomo encounter one another in the heat of a kli rishon, our teachers disagreed whether this is nat bar nat or not; for example, meat bowls that were rinsed in a milky cauldron with hot water that is yad soledet bo, even if both are ben yomo, for there are those who say it is permitted, as this is literally nat bar nat: the meat in the bowl, and the bowl in the water, and likewise the milky cauldron, and the two flavors are still of a permitted nature, and this is literally like fish that were served in a bowl. And this is provided that he says, "It is clear to me that there was no fat adhering to them," for if there was fat adhering even to one of them, then the second flavor is of a forbidden nature, unless there is sixty in the water against the substance of the fat on the surface of the bowl or the cauldron. But if it is not clear to him that there was no fat adhering, it is forbidden, for we say that presumably fat was adhering; and even though ordinary vessels are clean, as written in siman 94, it is different here because he is coming now to rinse them [Pri Chadash, subsection 12]. And this is the opinion of our teacher, the Beit Yosef, in section 3:

And there are some of our teachers who hold that even with clean vessels it is forbidden when both of them are ben yoman, for this is not nat bar nat, because the two discharges mix together; and when it discharges from the bowl into the water and from the cauldron into the water, the discharges meet and it becomes a second taste in the prohibition of meat and milk. Furthermore, the bowls themselves touch the cauldron itself and there is discharge from one to the other not by means of the water. This is the opinion of our teacher, the Rema, who wrote there: And there are those who forbid even if there is no fat adhering to them, unless one of the vessels is not a ben yoman from the absorption of a kli rishon, and then all the vessels are permitted and the water is treated as forbidden ab initio. But if both are ben yoman and one rinsed them together in a kli rishon, everything is forbidden, and such is our custom and one should not deviate. And specifically when they were rinsed together and in a kli rishon, but if they were rinsed one after the other, or in a kli sheni even together, everything is permitted. Thus far his words.

And his words are clear, that when one is not "of its day," everything is permitted, for the one that is "of its day" is permitted because it absorbed from the one that is not "of its day," and the one that is not "of its day" is permitted even though it absorbed from the one that is "of its day," but this is a "flavor from a flavor" of a permitted substance, since the one that is "of its day" was not forbidden, consequently all its discharge is of a permitted substance. And that which he wrote, "but if both are 'of their day' and he rinsed them together in a kli rishon everything is forbidden," he comes to add that even though he did not rinse the meat bowls in a milky pot, but rather rinsed both of them in another kli rishon, it is also forbidden, because of the discharges that mix as I have written, but in a case where they were rinsed one after the other it is permitted, since the flavors did not mix it is a "flavor from a flavor" of a permitted substance, and likewise in a kli sheni it is simple that it is permitted, for we hold (Shulchan Aruch Yoreh Deah 105:2) a kli sheni does not cause discharge and does not cause absorption.

And even in a case of one that is not of its day, if fat is stuck to them and there is not sixty in the water against the fat, if the fat is stuck to both of them, both are forbidden. And if the fat is stuck to one of them, that which has the fat is permitted, for it absorbs from that which is not of its day, and that which does not have the fat is forbidden because it absorbs from the fat. And if one is of its day and the second is not of its day and there is fat on one of them: if the fat is on that which is not of its day, everything is forbidden, for the one of its day absorbed from the fat and the one not of its day absorbed from the one of its day. And if the fat is stuck to the one of its day, it is permitted and the second is forbidden, as is understood [Pri Chadash, subsection 13].

And know that seemingly the prohibition we stated according to the view of those who are stringent is only regarding bowls that are a kli rishon of meat and of milk, for as for a kli sheni and a kli shelishi, they were never forbidden with a complete prohibition, neither regarding a prohibited substance nor regarding meat in milk. And if so, if one rinsed together bowls and plates and spoons of milk and of meat together in a kli rishon, we have no concern with it, for our bowls, their use is only as a kli sheni, as one pours from the pot into the bowl, and even when one pours and conducts iruy from the pot to the bowl, behold, iruy only causes absorption and emission to the extent of kedi klifah, and certainly plates, behold they are a kli shelishi, and so too the spoons. However, the author of the Issur V'Heiter HaAruch wrote [siman 34, ot 15] that the bowls and the plates and the spoons are also forbidden when one rinsed those of milk and of meat together. And his reason is that although iruy is only to the extent of kedi klifah, nevertheless, through the many times that one pours from the pot into them, and each time a small absorption remains in it, the absorption spreads throughout the entire vessel. And so too the plates, it is common to place hot meat upon them sometimes, and regarding milk, a hot solid mass of milk such as a milk pashtida and the like, and so too one pours from a pot onto the plates, and the spoons, it is their way to be inserted into a pot. Therefore, if it is clear to him that within this ma'at l'ma'at these bowls or plates or spoons were not used with the use of a kli rishon, one may permit it simply [Shach subsection 13 in the name of Torat Chattat], and the sage must investigate this from the questioner.

Our teacher, the Rema, wrote that if one poured from a kli rishon of meat onto a milk vessel, its law is like a kli rishon and it forbids if it was ben yomo; but if one poured boiling water that was neither of meat nor of milk onto milk and meat vessels together, and even if fat was stuck to them, everything is permitted, for irui is not exactly like a kli rishon such that it would cause the vessels one pours upon to absorb from one another; and if a milk bowl is found among meat vessels, we do not fear that perhaps they were rinsed together in a manner that they become forbidden. Thus far his words.

And we have already written in section 13 that these words of his are perplexing, for what did he see to forbid in the case of irui from a meat vessel onto a milk vessel? For this is literally nat bar nat, and even according to his approach that it is forbidden in the case of cooking, he himself ruled that after the fact it is permitted, and here, to forbid the vessel is considered after the fact, and in irui the mixing of expelled flavors is not applicable. Therefore, the great later authorities ruled that it is permitted in the case of irui [Shach subsection 5, and Mas'at Binyamin, and Pri Chadash subsection 17]. And even if there was fat stuck to them, one only requires kelipah according to the law of irui, and in a place where it is impossible to peel, it is permitted as was written in siman 91. And there is one who wished to provide a reason for his words, that we consider the stream of the irui as if it is in the vessel from which one is pouring [Taz subsection 13], and this is by reason of nitzok. And these are things that are not understood, to be so stringent regarding nat bar nat, [also the Pri Megadim is not comfortable with this, see there]. However, since it issued from the mouth of our teacher, the Rema, one should perform hag'alah on the vessel if it is of metal, and if it is of earthenware, one should not use it for twenty-four hours [the Gaon Rabbi Zalman Margolios in Beit Ephraim].

And conversely, they wondered about him regarding that which he was lenient in pouring boiling water over meat and milk vessels; for since he ruled that if one rinsed them in a kelli rishon it is forbidden, and pouring certainly cooks to the depth of a klipah, if so, it certainly causes absorption to the depth of a klipah even in a vessel (Shach subsection 20, and Peri Chadash there). However, regarding a klipah when it is impossible to peel, or when the klipah is not discernible, they were not stringent in this as is written in siman 91 (see Havat Daat subsection 11). And know that pouring from a forbidden vessel that is ben yomo certainly forbids to the depth of a klipah. And this which he wrote, that if a dairy bowl is found among meat vessels we do not fear lest they were rinsed together in a manner that they become forbidden. Thus far his words. That is to say, lest they were rinsed in a boiling kelli rishon, and not only that, but even if they are accustomed in that house to rinse in a kelli rishon they are also permitted, by reason of a sefek sefeika: perhaps they were not rinsed, and if you should say they were rinsed, perhaps it was not ben yomo (Taz subsection 14); and furthermore, we do not presume a prohibition; and furthermore, ordinary vessels are not ben yoman even the vessels of an Israelite, as is written in siman 122 (see Pri Megadim there).

Our teacher, the Beit Yosef, wrote in section 4: It appears to me that if they placed ash in the hot water that is in the cauldron before they placed the pots inside it, even though fat is stuck to them, it is permitted, for by means of the ash it imparts a flavor that impairs. Thus far his words. The commentators on the Shulchan Aruch disagreed with him, as this law is not found in any posek; and furthermore, if so, why did the poskim write not to perform hagalah on a vessel that was used within the day because it is a flavor that improves and requires sixty in the water against the absorbed [flavor]—let them place ash there [Shach, subsection 21]; and furthermore, that which they said in the Shas (Avodah Zarah 67b) that regarding the vessels of Midian the Torah prohibited vessels used within the day, behold it is possible to impair them with ash. However, many of the great authorities disagreed with them and sustained the ruling of our teacher, the Beit Yosef, for these are not precise objections at all, for is it that there are no bitter things that impair? However, the Torah and the poskim spoke only of hagalah that is by means of water alone; and furthermore, hagalah is not effective by means of ash at all, as is written in Orach Chaim siman 452 [Beit Yosef, ibid.]. And the simple custom among all authorities of instruction when a prohibited substance or meat is spilled under a pot of milk, or the reverse, in an oven, and there was ash there, is that they permit the cooked food even without sixty, and prohibit only the pot. And even though there are those who hesitate that perhaps in a single moment it does not impair, nevertheless they have so practiced, and the senses testify that you have nothing more impaired than this—even if they strain the cooked food, the taste of the ash remains, and it is obvious that a human being would not eat it. And so one should instruct. And also soap, which is called "seife," and our tallow candles impair greatly, and if they fell into the cooked food, they do not prohibit the cooked food.

It is permitted to place a vessel containing milk next to a vessel containing meat inside one chest, and we do not fear that perhaps some will fall from this into that and he will not know and will come to eat them as such; for since the meat and the milk are physically present, and everyone knows that they forbid one another, people are careful regarding it. And similarly, it is permitted to place a vessel containing milk next to a vessel containing vinegar, because even if a little milk falls into the vinegar, it will mix well and be nullified before he puts some of the vinegar into meat. And there are those who are stringent ab initio when both are uncovered, and it is good to be careful in this. But it is forbidden to place a vessel containing kutach next to a vessel containing salt if both vessels are uncovered, because people are not careful about falling from this into that since they do not forbid one another, and also their appearance is the same [Perishah], and there is reason to fear lest a piece of kutach fall into the salt without his knowledge, and the kutach is physically present and is not nullified within the salt, and he will put it into a meat cooked dish, or salt meat with it. However, even in this, if he transgressed and placed this next to that, it is permitted, and we do not presume a prohibition, and it is permitted to put the salt into a meat cooked dish and to salt meat with it. And the Rambam in chapter 9 (Rambam Hilkhot Ma'akhalot Assurot 9) explains the reason because the salt absorbs the flavor from the kutach, see there, and these laws are in the Gemara (Chullin 112a), and from this one may learn for everything similar to this:

Salt placed in a meat bowl is permitted by law to be placed in milk, for salting does not apply to vessels to cause them to emit or absorb. However, one should not permit it based on the principle of nat bar nat, for salt is a sharp substance, and the law of nat bar nat does not apply to a sharp substance, as I wrote in section 15. Nevertheless, it is proper to be stringent even in this case ab initio [see Taz subsection 18, and see Nekudot HaKesef]. In all the House of Israel, the simple custom is to have specific vessels for salt, for meat alone and for milk alone, as I wrote in siman 88, see there; and one who does so, may a blessing come upon him.