Your Pesach Questions, Answered

Tuesday, April 5, 2022

Have a question about the laws and practices of Pesah? Hadar’s Advanced Kollel is here to help! Check out the first few questions and answers below or fill out this form to receive an answer of your own.

I have a jar of peanut butter that has a hekhsher and the only ingredient listed is peanuts. Can I use it on Pesah?

Answer by Beth Levy
According to the Shulhan Arukh (OH 447:4), regarding food that was prepared before Pesah, as long as there is no significant risk that hametz has been mixed in with a food product, there is no problem with eating that food on Pesah

The Rema (OH 447:4) rules that, if solid hametz fell into a food product prior to Pesah, the entire product is prohibited on Pesah. This is true even if the hametz was removed, provided that there is a reasonable concern that pieces of hametz might have been left behind. (Such as a piece of bread that fell into a vat of wine.) The only way to permit the mixture at that point is to strain it prior to Pesah.

Most modern kashrut authorities certify things at a standard that matches careful home preparation, not after-the-fact standards to permit food. Therefore, they require supervision of food production to ensure that no hametz has accidentally fallen into the food. Nonetheless, it remains the case that, when you have no reason to think hametz got into an otherwise pure, non-hametz product, the food is permitted even if it has no special Pesah hekhsher.

Some modern authorities rule that peanuts are kitniyot (R. Tzvi Pesach Frank - Mikra’ei Kodesh II:60), and others disagree (R. Moshe Feinstein – Igrot Moshe OH 3:63). For those people who do not consider peanuts to be kitniyot, pure peanut butter, purchased before Pesah, would not require a special hekhsher for Pesah.

For someone who does not consume kitniyot on Pesah, may one prepare a food mixture which is up to 49% kitniyot based before Pesah and consume it on Pesah? Meaning, can one intentionally subsume the kitniyot within a mixture such that it is halachically nullified?

Answer by Matthew Anisfeld

Let’s break this question down into two parts. First we will look at the general rules regarding the nullification of kitniyot. We will then turn to the question of whether this can be done lekhathilah.

Nullification of Kitniyot

There are two key locations on the pages of the Shulhan Arukh that speak to the question of the nullification of kitniyot: OH 453:1 and OH 464:1. These two sources seem on the face of it as though they may contradict each other. A short analysis of these sources, and the way that the contradiction is resolved, will set us up well for understanding the contours of this question:

OH 453:1
The earliest source to deal with the nullification of kitniyot is a responsum by R. Yisrael Isserlein (Terumat HaDeshen #113). There, he rules that if one were to find a grain of kitniyot in a dish, that dish is not rendered prohibited. This rule is codified in the Rema (OH 453:1). Concerning the specific ratio, somewhat cryptically, all R. Isserlein says is that kitniyot is not like hametz which cannot be nullified on Pesah whatsoever. He does not specify the ratio at which kitniyot is nullified either on or prior to Pesah.

Hok Ya’akov 453:6 takes up the question of whether kitniyot requires a ratio of 1:60 in order to be nullified, or whether it is considered nullified as long it is the minority of the food. He notes that the Terumat HaDeshen sounds somewhat like he would require a ratio of 1:60, but argues that the Rema sounds like he thinks that it can be nullified as long as it is the minority. This is codified in the Mishnah Berurah (453:9). Nonetheless, any visible discrete pieces of kitniyot would have to be removed (MB 453:8).

OH 464:1
In the same responsa of R. Yisrael Isserlein, he explains that mustard is considered kitniyot, and therefore should not be consumed on Pesah. The Rema (OH 464:1) codifies this and writes that the custom is to refrain כלל/entirely from eating mustard on Pesah, even if it was mixed in prior to Pesah, because it is just like other types of kitniyot. The word ‘entirely’ sounds like the standard for nullification may be more stringent than requiring a mere majority of other non-kitniyot food.


This contradiction is resolved a number of ways by later commentators:

  • Taz (OH 464:1) argues that the prohibition in 464:1 is only a lekhathilah prohibition. According to this resolution, there would be no problem with eating a mixture containing kitniyot, so long as the kitniyot constituted a minority of the mixture. There would however be a problem with intentionally mixing kitniyot into food meant for consumption on Pesah, even if the mixture was combined prior to Pesah.
  • Mishbetzot Zahav (464:1) is troubled by this resolution of the Taz. OH 464:1 does not sound like it is only a lekhathila ruling. When the Rema says that the mustard is prohibited ‘even if it was mixed…’, it sounds like he is prohibiting a mixture containing mustard even after the fact. The Mishbetzot Zahav writes that perhaps what the Taz means is as follows: if it is the sort of thing that would last until after Pesah, it should not be eaten on Pesah, but otherwise it may be eaten on Pesah.
  • Hok Ya’akov 464:3 argues that the case of mustard mentioned by the Terumat HaDeshen and codified by the Rema is one in which there isn’t really any mixture at all. Rather, it is a case in which the mustard is the core element of the dish, and is distinctly visible. But typically, mixtures that contain a minority of kitniyot would be permissible even when mixed on Pesah.
  • Sde Hemed, Section 5, Hametz and Matzah 6:4 makes a similar distinction: The case of the mustard is one in which discrete pieces of mustard are identifiable. In that sort of case, one would have to remove the pieces of kitniyot (as the Mishnah Berurah cited above described). Mixtures containing a minority of kitniyot that is well mixed in are not prohibited.

In a similar fashion, Arukh HaShulhan 464:3 argues that the problem in the case of the mustard is that the mustard is the עיקר/primary ingredient. So long as kitniyot does not constitute the primary ingredient of a dish, it can be nullified as part of a mixture.


Talmud Bavli Bekhorot 27a relates that Rabbah would intentionally mix terumah (gifts designated for Priests) from outside of the land of Israel with permitted produce, and eat it. In Torat HaBayit HaArokh 4:3, the Rashba records two views that attempt to understand this behavior. There are some people who think that this behavior is reflective of a general rule: one is permitted to mix prohibited food with permitted food in order to nullify it, so long as that food is (1) only prohibited rabbinically, and (2) the rabbinic prohibition has no basis in the Torah. There are others, though, who view Rabbah’s behavior as reflecting a leniency that is local to Teruma from outside of the land of Israel.

The Rashba ultimately rules like this latter view: mixing forbidden foods—even those that are forbidden rabbinically, and even when the rabbinic prohibition has no basis in the Torah—with permitted foods in order to nullify them lekhathilah is prohibited. This ruling is codified in Shulhan Arukh YD 99:6.

Even though the Rashba and Shulhan Arukh marginalize Rabbah’s practice, viewing his practice as one that was reflective of an idiosyncratic rule about terumah from outside of the land of Israel, Pri Hadash OH 453:1 argues that kitniyot is another rare prohibition that falls into this category. According to this view, even on Pesah itself, it would be permitted to mix kitniyot with other produce, in order to nullify it and then eat it, so long as the kitniyot were only a minority of the final mixture.

Many Aharonim take issue with this ruling of the Pri Hadash. We have already seen that the Taz and Mishbetzot Zahav thought doing so was impermissible. Similarly, Shulhan Arukh HaRav 464:2, Kaf HaHayyim 453:25, and Arukh HaShulhan 453:2 all prohibit nullifying kitniyot lekhathilah.

Nonetheless, there are some Aharonim who argue that the prohibition of nullifying kitniyot lekhathilah only applies to mixing kitniyot with other food during Pesah itself. Prior to Pesah, there is no prohibition. (Be’er Yitzhak OH 11, Dvar Hevron 499 p. 259.)


The Ashkenazi practice of refraining from eating kitniyot is old and well established. If you usually refrain from eating kitniyot and have no particular need to eat it on Pesah, it makes sense to practice in accordance with poskim like the Taz, and refrain from preparing food that contains any kitniyot, even in advance of Pesah. And remember, even those who refrain from eating kitniyot permit eating them for health reasons. Even without a health-based concern, if there is some strong reason that you need to prepare food that contains kitniyot in advance of Pesah, you certainly have what to rely on. If you are going to do so, you must make sure of the following:

  • The kitniyot must not constitute a majority of the food in the dish.
  • Even if it is not the majority of the dish, it should not be the עיקר/main focus of the dish.
  • The kitniyot should be entirely mixed into whatever you are preparing, and there should be no discrete identifiable pieces of kitniyot.

What should I do about my porcelain kitchen sink – cover it with layers of foil or other material? If so, what other materiaI? Is it true that a porcelain sink cannot be kashered? 

Answer by Jamie Weisbach 

The standard position on ceramics is that they cannot be kashered. The earliest source for this is from Vayikra 11:33 where we are instructed to pass metal vessels that have come in contact with impurity through water, but to break ceramic ones - the implication is that ceramic cannot be repaired. The Gemara learns from this that this applies to food prohibitions as well; once ceramic has become prohibited, it cannot become permitted again.  

However, there are two positions in the Talmudim that complicate this slightly. First, in Zevahim 95b, the Gemara states that the issue with kashering ceramic is a concern that the owner will not do it properly for fear of breaking the ceramic with the heat, which implies that in theory ceramic could be kashered if this concern was mitigated. Additionally, in the Yerushalmi (Terumot 11:4), Rabbi Halafta ben Shaul permits kashering a ceramic pot that has been used with terumah by doing hagalah three times. Rabbi Ba says that one should not learn from this to a case of neveilah - improperly slaughtered animals. While it is not exactly clear how broadly this could be applied, this makes it clear that for the Yerushalmi, at least in some cases, ceramic could be kashered with hagalah done three times.  

The Ittur, picking up on the Yerushalmi, rules that any ceramic that only has a derabbanan prohibition, like terumah in a time when there is no temple, can be kashered with thrice-repeated hagalah, but d’oraita prohibitions, like neveilah, cannot be. The Rashba questions this, and asks if maybe Rabbi Ba’s limitation of this ruling means not only that hagalah three times doesn’t work for d’oraita prohibitions, but also for any d'rabanan that is judged to have roots in the Torah, and thus this would only work for a very limited range of cases. While the Rashba himself eventually concludes that he agrees with the Ittur, and permits hagalah three times for any d'rabanan prohibition, the Shulhan Arukh is strict for the Rashba’s concern, and therefore only cites this permission to kasher ceramic in the context of bishulei nokhrim, which is included in the category of d'rabanan that does not have a root in the Torah. What emerges from this is that by far the dominant view is simply not to kasher ceramic in most cases, although, as we will see, the position of the Ittur is occasionally revived by more recent poskim in cases where there are other reasons to be lenient as well. 

A second issue relating to your question is the status of porcelain – is it considered ceramic or not? This question first arose in the 1500’s when porcelain goods began to arrive in the West and drew the attention of Rabbinic inquiry. The Radbaz (3:401) holds that it has the same status as ceramic, and therefore cannot be kashered, and most poskim follow him. However, the Shayyarei Knesset HaHedolah (OH: 451) and the Sheilat Yaavetz (1:67) both hold that porcelain should have the status of glass rather than ceramic, which for Sepharadim would mean it doesn’t even need to be kashered at all. In fact, some of those who are strict are only strict in practice, due to concern of forged or improperly made porcelain (Pri Hadash OH 451:28). Because of this, Rabbi Eliezer Melamed (Peninei Halakhah Pesah 11:11 note 11) rules that in a case of need, one can kasher ceramic that has been manufactured properly and doesn’t have any cracks or breaks. 

As you can see, though there are debates, the standard approach to porcelain is to treat it like ceramic, and the standard approach to ceramic is that it cannot be kashered. Because of this, the most common way to deal with porcelain sinks is either to get a plastic basin to place inside the sink, or to line it with aluminum foil. If you want to learn more about how to approach this problem without kashering the sink, watch this video about kashering with R. Ethan Tucker, which discusses your options.  

However, if either of those options pose difficulties for you, there is another position which is important to know. Rabbi Ovadya Yosef (Hazon Ovadya Pesah, page 151) permits kashering porcelain sinks through doing irui (pouring boiling water) three times. He joins together several leniencies in making his argument. Firstly, a sink is mostly used with water that is not too hot to touch, and therefore, most of the flavor that is absorbed is not absorbed in a deep way. Secondly, even when it does have boiling water poured into it, there are those (Tosafot Shabbat 39a) who hold that this does not have the status of kli rishon but rather kli sheni, which also does not absorb flavor deeply. Finally, sinks are normally used with soap in the water, which transforms any flavors they absorb into a negative flavor, which is permitted on a d’oraita level. All of this, for Rav Ovadya, adds up to allowing porcelain sinks to be kashered with irui three times, relying on the position of the Ittur that even ceramic can be kashered with hagalah three simes for a d'rabanan prohibition. Rav Ovadya permits this even though he himself holds that porcelain is considered ceramic in every way. If one takes into account the lenient positions on porcelain mentioned above, there is an even stronger argument to permit kashering with irui three times.  

That being said, by far the most common normative position is to not kasher a porcelain sink, and if possible, you should try to either find a plastic basin or cover the bottom of the sink in aluminum foil. However, if you are in a position where not kashering it would pose difficulties, you could rely on Rav Ovadya’s position to ensure that you have a workable kitchen for Pesah