Pesachim 29

Accidental hametz contamination.

We have often seen how the rabbis’ ideals sometimes run up against the messiness of living in the real world. Case in point: Hametz is forbidden on Passover. But what if a tiny bit accidentally contaminates a large pot of otherwise kosher-for-Passover food. Must we throw the entire pot of food away? Today’s page offers three perspectives. Here is the first:

Rav said: With regard to leavened bread that becomes mixed with permitted food, the following distinction applies. During its time of prohibition (i.e., during the seven days of Passover) leavened bread is forbidden whether it is mixed with its own type (for example, when leavened flour is mixed with matzah flour or when unleavened matzah is mixed with leavened matzah) or it is mixed with another type of substance. Not during its time of prohibition (after Passover) if it is mixed with its own type of substance, then it is prohibited. However, if it is mixed with another type of substance, then it is permitted.

Two distinctions are drawn here: what is mixed (like with like, or two unlike substances), and when the mixing occurs (during Passover or afterward). Rav asserts that when leaven mixes with its own type of food — a bit of leavened dough that falls into matzah dough, say — the hametz is not nullified and the mixture, which is now essentially one big mass of hametz, is forbidden at any time, during or after Passover. When hametz falls into food that is not of its type — a crumb that falls into a pot of lentils, perhaps — the food is forbidden on Passover because of the severity of the ban on hametz, but after Passover it is acceptable.

Wait a minute, you ask, why would any leaven be forbidden after Passover? Rav holds that leaven that existed prior to Passover is forever forbidden. So even if you forgot to destroy it, you cannot eat it when the holiday is over and leaven becomes permissible again.

Shmuel takes a more lenient position than his colleague:

If leavened bread becomes mixed with permitted food during its time of prohibition, then the following distinction applies: If it becomes mixed with its own type of food it is forbidden, but if it becomes mixed with another type of food it is permitted. If it becomes mixed together not during its time of prohibition, but after Passover, then regardless of whether it becomes mixed with its own type or with another type of substance, it is permitted.

Shmuel agrees with Rav that hametz is not nullified by its own type on Passover; however, he does not extend the prohibition to a mixture with another type as did his colleague. And, if the mixing occurred after the holiday, Shmuel, who is of the opinion that one can benefit from hametz after the holiday has ended, rules that the hametz is nullified no matter the type of substance into which it falls.

Rabbi Yohanan presents an even more lenient position. He holds that:

With regard to leavened bread that falls into a mixture during its time of prohibition, whether it is mixed with its own type of substance or another type of substance, it becomes prohibited only when there is enough of the forbidden item to give flavor to the mixture. However, not during its time of prohibition, but rather after Passover, it is always permitted, regardless of whether it falls into a mixture of its own type of substance or whether it falls into a mixture of another type of substance.

During Passover, according to Rabbi Yohanan, the inadvertent addition of a small amount of hametz prohibits the dish into which it fell only if it imparts flavor to the dish — i.e., if you can taste it. Otherwise it is nullified, even in a dish of its own type during the holiday. After the holiday, it is not a problem.

None of these three — Rav, Shmuel and Rabbi Yohanan — unilaterally forbids all foods that accidentally incorporate a small amount of forbidden hametz. But they do have very different intuitions about what causes the mixture to be forbidden.

Read all of Pesachim 29 on Sefaria.

This piece originally appeared in a My Jewish Learning Daf Yomi email newsletter sent on December 20th, 2020. If you are interested in receiving the newsletter, sign up here.

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