In general, when a forbidden food becomes mixed with a permitted food, it is batel be-shishim (rendered insignificant if the forbidden food constitutes less than one sixtieth of the mixture); in such small quantities, it does not contribute flavor. At the level of Torah law, ḥametz is also batel be-shishim. The Sages, however, ordained that even a drop of ḥametz render a permitted food forbidden when mixed with it. Even if the quantity of permitted food is a thousand or ten thousand times greater than the ḥametz, the entire mixture becomes forbidden.
The Sages added this stringency because the Torah itself is more stringent about ḥametz than other forbidden foods: 1) Generally, if one consumes a Torah-forbidden food, the punishment is malkot (lashes), but one who eats ḥametz incurs the more severe punishment of karet (extirpation). 2) Whereas all other forbidden foods may be kept in one’s home, ḥametz can neither be seen nor be found in our homes throughout Pesaḥ. The Sages therefore continued in this direction by establishing a safeguard: even if a drop of ḥametz falls into a food, it is forbidden to consume or derive benefit from it. 3) All other forbidden foods are prohibited throughout the year, and we are therefore accustomed to distancing ourselves from them, but since we eat ḥametz all year long, we are liable to forget that it is forbidden on Pesaḥ. The Sages, therefore, are more stringent about ḥametz, so that everybody remembers to be careful about it.
This law, that even a drop of ḥametz renders a mixture forbidden, goes into effect with the onset of Pesaḥ. Before Pesaḥ, ḥametz is batel be-shishim like all other forbidden foods. Although the prohibition against eating ḥametz and the mitzva to dispose of ḥametz go into effect at midday on the 14th of Nisan, the law that ḥametz is not batel be-shishim does not take effect until Pesaḥ begins, when one who consumes ḥametz incurs karet and when the prohibition of bal yera’eh and bal yimatzei take effect (SA 447:2).
. According to She’iltot, Rabbeinu Tam, and Ha-ma’or, ḥametz has the same status as other forbidden foods and is batel be-shishim. All other poskim (including Rif, Rosh, and Rambam) maintain that ḥametz is not batel even in a thousand-to-one ratio, as per the opinion of Rava, following Rav, in Pesaḥim 30a. Even Rabbeinu Tam and Ha-ma’or refrained from acting leniently (see Berur Halakha ad loc.). However, MB 447:2 states, citing Aḥaronim, that where there are other grounds for leniency, one may combine the view of She’iltot and Rabbeinu Tam to support a lenient ruling.
The reasons for strictness about ḥametz are mentioned by Rashi, Rosh, Smak, Rabbeinu Yona, and many others. The first reasons are the principal ones, and therefore ḥametz becomes forbidden in a tiny quantity only once Pesaḥ begins. However, Rambam and Ramban explain that the reason a tiny amount of ḥametz is forbidden is that after Pesaḥ it will again become permitted, since on the Torah level ḥametzshe-avar alav ha-Pesaḥ is permissible, and anything that will become permissible in the future (davar she-yesh lo matirin) is not batel in any mixture. According to this opinion, the tiniest amount of ḥametz is forbidden from midday of the 14th. (This is the case only if it is mixed with the same sort of food item [min be-mino]. But the tiniest quantity of ḥametz renders a mixture with dissimilar items [min be-she’eino mino] forbidden only with the onset of the holiday, as explained in Magid Mishneh and Kesef Mishneh [MT, Laws of Ḥametz and Matza 1:5]. And according to Ran, there is a basis to forbid a mixture already from midday of the 14th, based on the rationale that we are not used to avoiding ḥametz. Accordingly, there are grounds to forbid a mixture with even the tiniest amounts of ḥametz starting from midday of the 14th, even min be-she’eino mino.) Nevertheless, SA 447:2 rules that tiny amounts of ḥametz render a mixture forbidden only once Pesaḥ begins, and most Aḥaronim accept this view.
As we have learned, the laws of ḥametz are uniquely strict: even a miniscule amount of ḥametz mixed with a permitted food renders the entire mixture forbidden for consumption or benefit. However, most poskim maintain that if the ḥametz is less than one sixtieth of the mixture, one may salvage its monetary value by selling it to a gentile. For example, if a kilogram of ḥametz falls into a metric ton of another food, one should throw away one kilogram, so as to avoid benefiting from the added ḥametz, and sell the rest to a gentile. This is because when the Sages forbade benefiting from such mixtures, their intention was to forbid benefiting from the ḥametz. Thus, if one disposes of a quantity of the mixture equaling the amount of ḥametz that was added, he does not benefit from it, and he may then sell the mixture to a gentile. If a single wheat grain of ḥametz fell into a large amount of cooked food, it all becomes forbidden to eat, and as long as it remains in a Jew’s hands, it is also forbidden to derive benefit from it. However, one may sell it to a gentile. It is not necessary to dispose of any of the mixture since the wheat did not cause the price to rise (SA 467:10).
Rema (447:1), however, rules stringently in accordance with the view of the few Rishonim who maintain that since it is forbidden to derive benefit from the mixture, it is likewise forbidden to sell it to a gentile. Rather, the entire mixture must be burned. This is the practice of Ashkenazim. However, in a case of a very large loss, even Ashkenazic custom relies upon the view of those who permit selling the mixture to a gentile (MB 447:3).
. There is a dispute as to whether ḥametz renders the entire mixture forbidden to derive benefit from. Raavad and Ramban forbid eating but not deriving benefit. According to Rif, Rosh, and most poskim, it is also forbidden to derive benefit. This is the ruling of SA 447:1.
However, according to Rif and Rosh, if one would discard the value of the ḥametz in the mixture, he would be permitted to sell the mixture to a gentile, since he obtains no benefit from the ḥametz; rather, he merely receives payment for the portion of the mixture that is not ḥametz. The overwhelming majority of poskim agree, and so states SA 467:10. However, Rema writes in Darkhei Moshe 447:2 that Mordechai, Terumat Ha-deshen, and Mahari Brin all adopt a stringent approach – that the entire mixture must be burned. MB 447:3 states in the name of Aḥaronim that one should sell it to a gentile. Moreover, SHT 467:74 states in the name of Beit Meir that if one will suffer a very large monetary loss despite selling the mixture to a gentile, he may even keep the mixture until after Pesaḥ, and then eat it or sell it to a Jew.
The Rishonim disagree about fundamental question: Is ḥametz that was batel be-shishim before Pesaḥ ḥozer ve-ne’or (“reawakened,” i.e., its nullification is reversed) when Pesaḥ arrives, and since on Pesaḥ ḥametz in not batel even in less than one part per thousand, it renders the entire mixture forbidden? Or does its bitul before Pesaḥ mean that it cannot be ḥozer ve-ne’or? For example, a crumb of ḥametz that falls into a large dish of cooked meat before Pesaḥ is obviously batel, and this food may even be consumed after midday on the 14th of Nisan. The question is whether it is still permissible to eat it after Pesaḥ begins.
Some poskim rule that if ḥametz was batel be-shishim before Pesaḥ, it is considered completely eliminated, and it cannot be ḥozer ve-ne’or on Pesaḥ. Therefore, the entire mixture is permitted for consumption (Rosh, Smag, Tur, and others). Other poskim say that the annulment that takes place before Pesaḥ is not effective; as soon as Pesaḥ begins the ḥametz reawakens, and the entire mixture is rendered forbidden (Rambam, Rashba).
This question has important implications for the status of matzot. Occasionally, some water drips on a mound of wheat grains, causing a few of the grains to leaven. It is very difficult to find these grains and remove them from the pile, but it is clear that the kosher wheat grains that did not become ḥametz outnumber the leavened grains by more than sixty-to-one. According to the view that ḥametz is ḥozer ve-ne’or, if all the wheat is milled together and matzot are baked from its flour, it will be forbidden to eat them on Pesaḥ, because the drop of ḥametz in it renders all of the matzot forbidden. It is therefore important to make sure that there is not even a single ḥametz grain in the wheat from which matza is made. But according to the opinion that ḥametz nullified before Pesaḥ is not ḥozer ve-ne’or, the matzot are kosher for Pesaḥ. There is no need to check the wheat kernels one by one in order to remove the leavened ones, because they were already batel be-shishim before Pesaḥ.
In practice, many poskim rule in accordance with the view that when ḥametz is batel be-shishim before Pesaḥ it is not ḥozer ve-ne’or, and therefore it is permissible to eat such a mixture on Pesaḥ. This is because, according to the Torah, ḥametz is batel be-shishim even during Pesaḥ. The Sages added the stringency of rendering a mixture forbidden because of even a drop of ḥametz. This means that the dispute about ḥozer ve-ne’or relates to a rabbinic prohibition, and when in doubt about a rabbinic dispute, the halakha follows the lenient opinion. This is the position adopted by most Sephardic Jews (SA 447:4).
Some rule that if the ḥametz that was batel be-shishim before Pesaḥ was fluid (laḥ), the halakha follows the lenient opinion, and the ḥametz is not ḥozer ve-ne’or. If, however, it was solid (yavesh), the law follows the stringent view, and it is ḥozer ve-ne’or. For example, if a drop of beer falls into another beverage, it blends with the liquid and ceases to exist independently. As a result, after being nullified, it is not ḥozer ve-ne’or and does not render the mixture forbidden. However, if a crumb of ḥametz falls into a solid food, because it continues to exist independently and does not blend with the mixture, it has a degree of significance. Therefore, when Pesaḥ arrives it is ḥozer ve-ne’or and renders the entire mixture forbidden (SA and Rema 447:4, based on Terumat Ha-deshen). This is the approach adopted by Ashkenazim and some Sephardim.
Flour, because of its fineness, is considered a fluid mixture. This is because the distinction between fluid and solid depends principally upon whether or not the forbidden food blends completely with the permitted food. In a fluid mixture, the forbidden food blends completely with the permitted food, and in a solid mixture the forbidden food remains independent. Accordingly, there is no need to check the wheat grains before they are milled and baked into matzot, because after the wheat is milled, the flour produced from the leavened grains will be nullified and blend completely with the rest of the flour, and when Pesaḥ arrives it will not reawaken to render the mixture forbidden (SA and Rema 453:3).
Based on this principle, some poskim say that it is best to bake matzot before Pesaḥ so that if even a tiny quantity of flour or dough becomes ḥametz during the kneading process, it will blend with the rest of the dough and be batel be-shishim before Pesaḥ. This assures that it will not reawaken and render the matzot forbidden during Pesaḥ. Likewise, with respect to machine matzot, sometimes tiny particles of dough get stuck in the tines of the machine during kneading, and they remain there long enough to become ḥametz, whereupon they fall back into the dough. However, because the pieces of dough that became ḥametz blend completely with the rest of the dough, it is considered a fluid mixture, and since the ḥametz is batel be-shishim before Pesaḥ, it is not ḥozer ve-ne’or.
All of this is be-di’avad, but le-khatḥila we take special care to bake matzot in which there is no concern that even the tiniest bit of ḥametz got mixed in. Those who are meticulous take care to eat matza from wheat that was guarded from the moment it was harvested, which is acceptable even according to the stringent view that ḥametz is ḥozer ve-ne’or even in a mixture of fluids with fluids (below, 12:5, n. 5).
. The custom of the Sephardim: Kaf Ha-ḥayim 447:76-78 states that many Sephardim have the custom to be stringent about ḥozer ve-ne’or, and this is the opinion of Pri Ḥadash and Ḥida in Birkei Yosef 447:14. It seems that these authorities were also stringent about liquid mixtures. Kaf Ha-ḥayim adds that Sephardim have the custom to be as strict as Rema, but no more. This is similar to what Zekhor Le-Avraham states: Sephardim on Pesaḥ follow Rema. Nonetheless, SA cites the lenient position anonymously, which indicates that it is completely lenient in this matter. Additionally, Yabi’a Omer OḤ 2:23 expands on the topic and upholds the lenient view, which is the view of most Rishonim, that it is not ḥozer ve-ne’or. Moreover, according to She’iltot, ḥametz is batel be-shishim even on Pesaḥ, and even those who are stringent maintain that this prohibition is rabbinic, and in a dispute about rabbinic law we are lenient.
The view of Shulḥan Arukh warrants closer study. SA (442:4) cites Rambam that “tiryaka” (“theriaca,” a type of medicine) is prohibited on Pesaḥ since the concoction contains a drop of ḥametz, as it is ḥozer ve-ne’or once Pesaḥ begins. This seems to contradict the lenient ruling in SA 447:4. According to Rema, SA retracted what was written in §442 and permitted ḥozer ve-ne’or. Pri Ḥadash explains that ḥozer ve-ne’or applies in a case where one intentionally mixed ḥametz into the mixture. Taz states that tiryaka is forbidden because the ḥametz in it acts as a stabilizer (davar ha-ma’amid) in the mixture.
It is also important to note that even according to the lenient opinions that ḥozer ve-ne’or is permitted (according to SA – in all cases; according to Rema – in liquid mixtures), it is forbidden to intentionally blend ḥametz into a mixture before Pesaḥ and annul it in a sixty-to-one ratio in order to eat the mixture on Pesaḥ (as per Pri Ḥadash’s explanation of SA and MB 447:102 at the end). Only ex post facto, when the ḥametz was mixed in unintentionally, may it be eaten le-khatḥila. According to the stringent opinions, since the mixture may not be eaten, it also may not be kept in one’s house, though be-di’avad, if he kept the mixture in his house over Pesaḥ, he may eat it after Pesaḥ (MB 447:102).
MB 453:32 states that according to Taz, if a bit of ḥametz was already mixed in before Pesaḥ and there are less than sixty parts of permissible food in the mixture to annul the ḥametz, one is permitted to add more permissible food to the mixture to nullify the ḥametz. However, MA and most poskim maintain that this is forbidden, since it appears that he is intentionally trying to nullify a forbidden food. In extreme situations one may rely on the lenient opinions.
. Terumat Ha-deshen 1:114 states that flour is considered a fluid mixture, and this is the opinion of the majority of poskim, as MB states in 447:32. However, Baḥ states that according to Smak and Raavyah, flour mixed with flour is considered a solid mixture; therefore, one should preferably take care that no leavened flour mixes with the matza flour. This is also the view cited in MB 453:17 and SHT 25. Additionally, it is clear that le-khatḥila one should take into consideration the opinions that all ḥametz reawakens on Pesaḥ, whether solid or fluid.
There are three views regarding the rationale behind ḥozer ve-ne’or. According to the most stringent view, even in the case of a fluid mixture, and even if the ḥametz itself has been removed and only a minuscule amount of it was absorbed into the mixture and is not discernible, it is still ḥozer ve-ne’or. In contrast, MB 453:17 mentions the more lenient view of Olat Shabbat and Eliya Rabba that the ḥametz is ḥozer ve-ne’or only if one re-cooks the mixture, for only then does the ḥametz contribute more taste to the mixture. If it is not re-cooked, it is not ḥozer ve-ne’or. The mainstream view, as MB states ad loc. based on MA, is that ḥozer ve-ne’or applies to solid foods, i.e., only when there is actual, substantial ḥametz remaining in the mixture.
There is a well-known rule that something that imparts foul taste (“noten ta’am li-fgam”) does not render a mixture forbidden. For example, if non-kosher meat falls into a pot of kosher food, and the quantity of kosher food is sixty times that of the non-kosher meat, the taste of the non-kosher meat is nullified, and it is permitted to eat the cooked dish. If the kosher food is not sixty times the quantity of the non-kosher meat, since its taste is discernible, the cooked dish is forbidden. If, however, the taste of the non-kosher meat is foul (“pagum”), since it spoils the cooked dish, then as long as the kosher food constitutes the majority of the mixture, it is permitted to eat it (SA YD 103:1).
What about a ḥametz mixture on Pesaḥ? Some say that the fact that the Sages, due to the gravity of the ḥametz prohibition, ordained that even a drop of ḥametz renders any mixture forbidden indicates that the matter does not depend upon the taste it gives to the mixture. Therefore, even when it contributes a foul taste, it is no different than a drop of ḥametz that renders its entire mixture forbidden (Rashbam, Rashba).
The opinion of most Rishonim is that ḥametz is like other prohibited foods except with regard to bitul be-shishim. Thus, in cases like noten ta’am li-fgam, where other forbidden foods would not render a mixture forbidden, ḥametz also does not render a mixture forbidden (Rabbeinu Tam, Ri, Rosh, and Mordechai).
In practice, SA 447:10 rules leniently whereas Rema writes that in Ashkenazic communities the custom is to follow the stringent ruling that even a drop of foul-tasting ḥametz renders an entire mixture forbidden.
. The Rishonim disagree about the status of forbidden foods that the Sages determined are not nullified even in one part per thousand, like ḥametz on Pesaḥ and yein nesekh. Some are stringent and maintain that just as we are stringent about even the smallest quantity, so too we are stringent if it contributes foul taste. This is the view of Yere’im §52; Raavyah, Pesaḥim §464; Roke’aḥ §487; Or Zaru’a, Avoda Zara §262; and Responsa Rashba 1:499. Against them, most Rishonim maintain that only good taste is not nullified even in one part per thousand, but foul taste does not render a mixture forbidden. This is the view of Rabbeinu Tam; Ri; Ramban; Smag, negative commandment §78; Rosh, Avoda Zara 5:6; Ritzva ad loc.; Nimukei Yosef, Pesaḥim 30b; Ra’ah; and Rashbatz.
The custom of most Ashkenazic communities is to be stringent, but MA and MB 447:98 state (based on Terumat Ha-deshen §128) that where there is no established custom, one should rule that one who acts leniently has done nothing wrong, though one who acts stringently is commendable. The prevailing Sephardic custom follows SA, as stated by Pri Ḥadash, Ḥida, Mahari Ayash, and others, for in addition to the fact that most Rishonim are lenient, this dispute is about a rabbinic enactment, in which halakha follows the lenient view. Even so, some accept the stringent practice, as stated by Kaf Ha-ḥayim 447:228. Rema 447:2 states that the custom to be stringent about ḥametz pagum only applies once Pesaḥ begins, but before the onset of the holiday, the ḥametz is nullified even in less than a sixty-to-one ratio, like any other prohibited food that befouls a mixture.
The Torah law concerning a ḥametz mixture is complicated, subject to dispute among Tanna’im, Amora’im, Rishonim, and Aḥaronim. We shall summarize its laws here succinctly.
The Torah declares that one who eats a kezayit of ḥametz on Pesaḥ incurs karet. If ḥametz that was mixed with other foods such that there was a kezayit of ḥametz within a shi’ur akhilat pras (three or four eggs’ bulk), and one ate a shi’ur pras of the mixture, then according to Ramban and other Rishonim, he incurs karet, while Rif and Rambam maintain that his punishment is only malkot (lashes). (According to Rabbeinu Tam, even if he ate only a kezayit of the mixture, he incurs punishment from the Torah, as cited by Rosh, Ḥullin 7:31.)
If the mixture does not contain a kezayit of ḥametz within a shi’ur akhilat pras, and one ate a quantity of the mixture that has a kezayit of ḥametz: according to Ha-ma’or and Itur, he incurs malkot, but according to Tur, whether he ate a lot of the mixture or just a little, if the mixture has the taste of ḥametz, he has violated a Torah prohibition, but he does not incur lashes; according to Rambam, he has violated only a rabbinic prohibition. (According to Rambam and SA 453:2, in a mixture of wheat and rice, if the taste of the ḥametz is discernible, eating only a kezayit constitutes a violation of a Torah prohibition.)
If ḥametz was mixed with food of the same type – for example, leavened flour with unleavened flour – since they taste the same, the ḥametz flour is nullified by the majority (batel be-rov) at the Torah level, but it is still rabbinically prohibited (SA 447:1).
Regarding the prohibition against keeping ḥametz on Pesaḥ, if a kezayit of ḥametz becomes mixed with other food, as long as it is less than sixty times the quantity of the ḥametz, one violates bal yera’eh and bal yimatzei. If the mixture is more than sixty times the quantity of the ḥametz, the ḥametz is batel at the Torah level and no prohibition is violated. Likewise, if the ḥametz becomes mixed with its own kind – for example, leavened flour with unleavened flour – that has the same taste, if there is more kosher flour than ḥametz flour, then according to Torah law the ḥametz is batel and no prohibition is violated. Nevertheless, even though no Torah prohibition is violated in these scenarios, the Sages ordained that the mixture must be eliminated, lest one eat it on Pesaḥ.
. If one did not eliminate it, since he did not violate bal yera’eh and bal yimatzei he may benefit from it after Pesaḥ. As for eating it after Pesaḥ, Eliya Rabba claims that since he violated a rabbinic prohibition by keeping it over Pesaḥ, he may not eat it, although according to MA, he may eat it (MB 447:102).