Questions and Answers from Hadar's Pesah Halakhah Hotline
Tuesday, Apr 04, 2023

If a person's custom is to eat up or destroy or give away to a non-Jew everything that's considered hametz gamur, do they still have to sell products that are not hametz gamur, like ketchup, mayonnaise, mustard, popcorn, rice krispies, corn flakes, vinegar? 

Answered by Jamie Weisbach

To begin with, if hametz is mixed into other foods prior to Pesah, it is batel b’shishim (Shulhan Arukh OH 447:4).  Therefore, if the hametz is less than one sixtieth of the total mixture, it is permitted on Pesah, even for eating, and certainly does not need to be sold.  While it is prohibited to deliberately create such a mixture in order to eat it on Pesah, it is permitted to buy or simply keep items like this. 

The relevant question here is whether mixtures containing hametz at a higher ratio than one sixtieth need to be sold, or can simply be put away and not eaten until after Pesah.

The Mishnah in Pesahim (3:1)  states that one transgresses Pesah due to mixtures containing hametz.  Rabbeinu Tam says that this Mishnah is referring only to the prohibition on eating hametz mixtures, but not to a prohibition on possessing them.  Therefore, according to this approach, it would be permitted (at least on a Torah-level) to keep mixtures containing hametz over Pesah as long as you did not eat them.  However, Rashi and Rambam (Hilkhot Hametz u’Matzah 4:8)  both say that this Mishnah also refers to the prohibition of bal yera’eh and bal yimatzeh -- that hametz should not be seen or found in the possession of a Jew on Pesah . 

If bal yera’eh and bal yimatzeh apply to hametz in mixtures, the next question is what ratio of hametz this prohibition kicks in at; do the prohibitions on eating and possessing hametz mixtures apply at the same ratios , or might they apply at different ratios of hametz in the mixture?   According to the Rambam, you are not liable for eating mixtures containing hametz unless they have a ratio of one olive’s bulk (kezayit) of hametz per the amount of that mixture you could eat in the time it takes to eat a loaf of bread.  This is because one is only liable for eating hametz if you eat a kezayit, so for mixtures as well,  you need to be able to eat that minimum quantity of hametz in a single act of eating in order to be liable.  What is not clear in the Rambam is whether this is also the ratio at which you are liable for possessing hametz.  The Maggid Mishnah (Hilkhot Hametz u’Matzah 4:8) brings two interpretations of the Rambam on this.  He personally argues that the same ratio applies, and therefore you are not liable for possessing hametz mixtures below this ratio.  Additionally, the Maggid Mishneh brings the position of Moshe HaKohen of Mainz who says that one can be liable for possessing hametz on Pesah even below this ratio.  In the Kesef Mishnah (Hilkhot Hametz u’Matzah 4:8), Rabbi Yosef Karo, (the author of the Shulhan Arukh) says that he thinks the second approach makes more sense; we are talking about owning the hametz, not eating it, so why would a ratio about the way you eat it matter in this case? 

The Shulhan Arukh (OH 442:1) simply says that you are liable for possessing mixtures of hametz during Pesah, and does not clarify his position on the relevant ratios.  The Mishnah Berurah (442:1) states that the Shulhan Arukh follows the position laid out in the Kesef Mishnah and holds that you are liable for keeping hametz mixtures over Pesah at any ratio, because all of the hametz in the entire mixture is joined together and there is, all told, a kezayit of hametz present, even if it is distributed throughout the mixture. 

According to the explanation of the Mishnah Berurah, it seems like if there was not a kezayit worth of hametz in the entire mixture that you might not be liable for keeping it over Pesah.  However, the Mishnah Berurah (442:33) notes that there is significant disagreement among the Rishonim on whether one can be liable for bal yera’eh and bal yimatzeh even at a volume less than a kezayit, and the weight of these stringent positions makes him hesitant to permit keeping hametz even in cases where it is smaller than a kezayit.  While the Beiur Halakhah (447:11, d.h. “bein”) suggests that perhaps the stringent position only applies when the hametz is b’ein (visually identifiable as hametz) and not when it is in a mixture, he is not willing to rely on this interpretation practically. 

It therefore seems that any mixture containing hametz above a ratio of one sixtieth is included in the prohibitions of bal yera’eh and bal yimatzeh and needs to be sold on Pesah.  Potentially, mixtures which do not contain a kezayit total of hametz (even if they are above the one sixtieth ratio) could be permitted to keep, but in most cases it seems to me that this would be difficult to assess, particularly for processed foods where the precise ratios and amounts of each ingredient are impossible to determine.  I would therefore recommend selling anything that you know contains hametz unless you are certain it is batel b’shishim.  Even if you normally refrain from selling hametz and prefer to get rid of it entirely, I think it makes sense to rely on the sale for these items because there are positions in the sources, such as Rabbeinu Tam, that would permit keeping them entirely.  

This year I got two pet rats who eat kibble as their primary food. However, this kibble contains several types of grain, and as we get closer to Pesah, I am wondering what the halakhah is around keeping pet food over the holiday. My pets could probably eat food without grain for the week. I would have to make it myself, and I'm sure they'd be happy, fat rats by the end of it. But is that necessary? Should I dispose of any remaining food, or is pet food permitted to keep?

Answered by Jamie Weisbach

There are three prohibitions regarding hametz

  1. Eating it
  2. Benefitting from it
  3. Possessing it 

Regarding feeding your rats food containing hametz, you will confront issues of both benefiting from hametz, and owning the hametz.  Even if the hametz in the rat kibble is not anything that you would be willing to eat, the standard for hametz becoming permitted due to being unfit for consumption is whether or not a dog would eat it (Shulhan Aruch 442:2).  It seems to me that if it is fit  for rats to eat it probably is also something that a dog would eat, and therefore prohibited for all of the prohibitions above.  

Some people in these circumstances recommend doing a sale of both the hametz and the animal, that way you neither own hametz (because the hametz is no longer yours) nor benefit from it (because the rats are no longer yours).  However, this is not so simple.  The Shulhan Arukh (OH 448:6) prohibits feeding hametz even to an animal that is not yours.  The Mishnah Berurah (448:28)  explains that this is still considered benefit because you derive pleasure from the experience of feeding an animal, even one that is not yours. It seems to me that this concern is especially relevant in a case like this when these rats are your pets the rest of the year and you have an emotional attachment to them and are accustomed to caring for them.  

Another approach is to ask whether this kibble is really the kind of hametz that is problematic in the first place.  The Hazon Ish (OH 116:7) argues that hametz is prohibited until it is unfit for a dog to eat only if it is pure hametz , like a loaf of bread.  However, a mixture containing hametz that would not be usable as a raising agent for anything else is only prohibited when it is fit for a human to eat.  It’s therefore possible that if the rat kibble in question is both a mixture of hametz rather than primarily consisting of hametz, and is completely unfit for human consumption, that it would be permitted entirely to own and benefit from on Pesah.  Whether this is applicable in your case will depend on the ingredients in your rat kibble and whether you judge it to be completely unfit for human consumption or not.  

Given that this can be difficult to assess, and not all poskim agree with this approach, I would recommend changing their diet, and either giving away or doing a sale for the kibble that you feed them the rest of the year. 

With respect to stainless steel utensils pursuant to the scientific research of the Israeli physicist and rabbi, R. Prof. Dror Fixler: To what extent can one, whether Ashkenazi or Sefaradi, rely on the conclusions of this research that scientifically prove that the level of absorption of stainless steel materials is significantly lower than that of glass? To what extent does the halakhic process take into account empirical halakhic data, or does it operate independently when determining the reality, inasmuch as legal reality can many times be different than “actual” reality?

Answered by Matthew Anisfeld

The recent materials revolution has indeed raised questions about how kashrut-observing Jews should relate to modern kitchen utensils. The research by R. Prof. Dror Fixler was particularly thorough and rigorous in its scientific approach, but, interestingly, he was by no means the first person to conduct such empirical research. Indeed the Radbaz (C16, Spain) in his responsum 3:401 writes in some detail an experiment that he did to determine whether a new kind of porcelain was capable of absorbing and conferring flavor from and to the food that was cooked in it. While the Radbaz determined that the material that he was dealing with was in fact capable of absorbing and conferring flavor, his research seems to point to a background assumption that the status of various materials vis-a-vis kashrut is determinable empirically.

There are some modern poskim who have entirely rejected the premise that the kashrut status of materials should be determined empirically. For example R. Asher Weiss (Tehumim 34, p. 128) argues that the status of materials was determined by the Sages of the Talmud, and halakhic claims based on empirical research risks destablising large swathes of the tradition.

On the other hand, many poskim have argued that the halakhic status of materials is entirely grounded in their capacity to transfer flavor. Materials are only problematic insofar as they confer the flavor of the food that was previously cooked in them, to the food that is currently in them. These poskim point to various passages in the Gemara and Rishonim where the status of a particular utensil is determined by its capacity to transfer flavor. For one example, see this passage from the Gemara is Pesahim:

Bavli Pesahim 30a
They raised a dilemma before Ameimar: certain glazed [konya] vessels, what is the halakha with regard to using them during Passover? … Ameimar said to him: I saw that some of the liquid is expelled [demidayeti]? Apparently they absorb and are prohibited.

Here, Ameimar is asked to determine the kashrut status of glazed vessels. He rules that they are problematic, but, crucially, he does so on the basis of his experience.

With this empirical basis in the background, there have been a range of different views as to how we should think about modern materials. The most conservative position is one that accepts that the status of materials was initially established on the basis of the empirical reality, however, after these statuses were establishes, they were fixed as halakhic principles. People who take this approach argue that the fixed halakhic statuses of materials is an important way to avoid confusion. (See, for example R. Ya’akov Ariel and R. Ratzon Arusi in Tehumim 34, pp. 125, 129). 

In a similarly conservative vein, some poskim have argued that the halakhic status of materials is determined empirically, but nonetheless, the custom of kashering utensils is so old and venerable, that we should not veer from it, even in a new reality. (See, for example R. Aharon Pfeuffer in Derekh Kokhav, pp. 311-312).

Contrastingly, there are some poskim who accept the new empirical reality, and although they are unwilling to fully go the full nine yards, will use this reality as a reason to be lenient in a case of doubt. (This is reported to be the view of R. Shlomo Zalman Auerbakh in Megillat Sefer al Basar Beḥalav Veta’arovet 96, 16.)

R. Naḥum Rabinowich (Tehumim 34, pp. 126-127) argued that a distinction should be drawn between lekhathila cases and b'diavad cases. Setting up a kitchen in which there is no separation between different utensils risks accidents happening. But in b'diavad cases, there is no reason to be stringent. (For a detailed analysis of the potential scope of the concepts of lekhathila and b'diavad, see this essay by R. Ethan Tucker.)

Lastly a number of contemporary poskim have argued that in principle, one should freely be able to use utensils that do not confer flavor, even when they have been used for prohibited food, even lekhathila. (See, for example, this article by R. Roi Sitton). They argue that there are risks associated with being stringent when there is no logic to acting stringently: it may cause people to feel alienated from Torah and halakhah more broadly. Nonetheless, many of these poskim are reluctant to bite the bullet fully until there is a broader consensus. 

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