Transfer of Taste (3)

  • Rav David Brofsky

Iruy and Proper Use of Sinks (3)




In previous shiurim, we discussed environments in which taste can be transferred from one substance or utensil to another.  We noted that while we clearly require the proper medium (such as a liquid) and heat (yad soledet bo), the authorities debate whether the location of the encounter between two substances is important.


A keli rishon, i.e., a utensil which was heated on the fire, even after it was removed from the fire, is certainly an environment conducive to the transfer of taste.  However, we questioned whether a keli sheni, or even iruy, could also facilitate a netinat ta'am.


Regarding a keli sheni, the Shulchan Arukh (YD 105:2) rules in accordance which the majority of Rishonim who believe that just as a keli sheni cannot accomplish bishul on Shabbat, it also cannot induce a transfer of taste.  Many Acharonim (Shakh and Taz), however, seem inclined to adopt, except in extenuating circumstances, the stringent view of the Rashba and Maharshal, who maintain that a keli sheni can transfer taste to at least a kelipa (outer layer) of the substance. 


Regarding iruy - i.e., the pouring of a hot liquid from a keli rishon onto a cold substance - we noted that the Rishonim debate whether contact with this liquid is similar to contact with a keli sheni or with a keli rishon.  The Shulchan Arukh rules that iruy can facilitate an absorption or extraction of taste "kedei kelipa."


This week, I would like to address a common application of the laws of iruy – sinks.


Pouring Hot Water onto Dishes – Potential Problems:


Last week, we cited two comments of the Rema which drew criticism from the Shakh.


Firstly, we learned in a previous shiur that the Rema (95:3) rules, in accordance with the opinion of the Sefer Ha-Teruma, that if one places a dairy dish which is ben yomo (has been used within the last 24 hours) into a ben yomo meat pot filled with boiling water, the entire contents are prohibited. 


Does this stringency apply even if one pours water from a ben yomo meat pot onto a ben yomo dairy pot?


The Rema rules that when one pours hot water from a ben yomo dairy keli rishon onto a ben yomo meat pot, the meat (bottom) pot is prohibited. 


The Shakh (95:5) disagrees and suggests that be-di'avad, especially if a financial loss is involved, one should NOT prohibit the bottom pot.


Secondly, the Rema rules that if hot water is poured from a keli rishon onto ben yomo meat and dairy dishes together, even if they are not clean, the dishes are permitted.  He explains that iruy is not considered a keli rishon to the extent that it can cause both the extraction of taste (or the heating up of a substance) and its subsequent absorption into another utensil.


The Shakh once again disagrees, and in this case rules more stringently than the Rema.  He maintains that if the two dishes are dirty, they are prohibited.  He questions whether one should also be stringent if only one of the dishes is dirty and recommends stringency if no great financial loss is present.  In other words, the Rema and Shakh debate whether iruy of hot water has the ability to cause the "be'ein" (substance) of milk and/or meat to be heated and absorbed into another utensil.


The ramification for modern usage of a sink should be clear.




Firstly, we should note that most authorities seem to view hot water from the tap as iruy mi-keli rishon, despite the fact that the boiler may be located quite far from the sink.


One may suggest that the status of the water should be similar to the status of water taken by a ladle from a keli rishon.  The Taz (end of YD 92) cites the opinion of the Maharil who views iruy from a ladle as iruy from a keli sheni.  The Taz disagrees, but notes that if the ladle remained in the keli rishon for some time, everyone would agree that it is considered to be a keli rishon.


Moreover, maybe the first burst of water should be subject to the debate between the Taz and Maharil, but certainly once the pipe as been exposed to hot water for a period of time, the water should be considered iruy mi-keli rishon.


Needless to say, tap water only presents a halakhic problem if it is yad soledet bo.  This is often not the case, as it is uncomfortable to wash dishes in very hot water.


With that in mind, clearly one avoids many potential kashrut quandaries by acquiring two separate sinks.  The only question remaining would relate to the proper method of washing a pareve utensil in a meat or dairy sink.  As we discussed in previous shiurim, this does not pose a major problem, and one should simply avoid contact between meat or milk and the pareve pot.  If such contact were made, under hot water, it would seem, based on a number of considerations, that the pot may still retain its pareve status.


At the other end of the spectrum, washing both dairy and meat dishes in the same sink simultaneously would seem to pose the greatest problem.  The debate between the Rema and Shakh would certainly be applicable.  While in such a case, there may still be many reasons to be lenient (i.e., was the water really yad soledet bo? was soap used? can the dishes be kashered?), a halakhic authority should be consulted.  In any case, this is certainly not a le-chat'chila method of washing dishes.


May one use one sink for consecutive washing of meat and dairy dishes?


Firstly, the sink must be washed thoroughly between use for meat and dairy dishes.  Otherwise, one may be subject to the debate between the Rema and Shakh.  In other words, the Rema's scenario of hot water from a keli rishon poured over dirty meat and dairy dishes is strikingly similar to pouring hot water over a sink with meat residue and a dirty dairy dish.  The Shakh, as we mentioned, is stringent in this case.  Therefore, it is crucial that the sink be thoroughly cleaned.  This reason alone may be sufficient, according to some, to encourage the use of washing basins or inserts as opposed to racks. 


Assuming the sink is clean, one must ask the following questions.


Are we concerned that the sink itself truly absorbed taste, and has it really attained the status of being "not kosher"? Furthermore, are we concerned that the sink may emit taste and render the dishes inside "not kosher"?


Rav Moshe Feinstein zt"l (Igrot Moshe YD 1:42) notes that it is quite difficult for a sink to become not kosher.  He insists that a sink can only absorb ta'am if it is poured directly, from a hot keli rishon onto the sink, or if a hot stream of tap water is poured directly over food residue.  He claims that the probability of this happening with both meat and dairy substances, within 24 hours of each other, is low.


Furthermore, it is virtually impossible, even if the sink has become treif, for the sink to affect other dishes.  After all, iruy, according to the Rema, cannot effect two transfers of taste.  Therefore, iruy cannot enable an extraction and subsequent absorption of non-kosher taste.


Soaking dishes in the sink may also present a problem, although we noted that many authorities are lenient regarding a keli rishon, and certainly when two transfers of taste are involved (Maharshal).


Rav Moshe concludes that one may use one sink for both meat and dairy dishes consecutively, yet notes that common custom is to use separate dairy and meat racks.  He does not mention a pareve rack, although many have adopted the custom of using a pareve rack for pareve pots and dishes.


If a dish or silverware should happen to touch the bottom of the sink, it would not require kashering.


The Minchat Yitzchak (2:100) adopts a more stringent approach, and requires one to thoroughly clean the sink and then use separate basins for meat and dairy.  (Interestingly, when this opinion was presented to Rav Moshe, he wrote that he will certainly receive complaints of "Rebbe you have made it so difficult for us!" (Igrot Moshe). 




One of the most common kashrut questions involves the use of sponges.  What if one washes dairy dishes with a meat sponge?


In general, it is quite difficult to construct a case in which this presents a serious kashrut question.  Seemingly, in order for there to be a problem, a stream of hot, yad soledet bo water must fall directly on a piece of meat on the dairy pot.  Alternatively, the water may fall onto both a dirty sponge and pot, in which can the Shakh, cited above, may be stringent.


Usually, however, the sponge is clean, or the water is not hot enough to present a problem, or the stream of water was interrupted, or one used soap (which renders he taste defective), and therefore the pots or dishes are permitted.  Furthermore, often the meat residue is insignificant in size and therefore may not pose any problem.  However, in case of doubt, one should consult with a halakhic authority.


Preferably, one should have at least two sponges (dairy and meat), if not three (for pareve pots or utensils).


Next week, we will begin our study of reicha and zeia (smell and steam) and their practical ramifications relating to ovens and microwaves.