Kashrut for Passover

The Torah commands eating unleavened bread for seven days and forbids eating anything leavened during them; for a violation it prescribes the penalty of karet. It also forbids leaven to be found in the house at all.¹

From the verses “no leavened bread shall be seen with you” and “no leaven shall be found in your houses” tradition derives two prohibitions of ownership: bal yera’eh (בַּל יֵרָאֶה) and bal yimatze (בַּל יִמָּצֵא). On Passover it is thus forbidden to eat chametz, to derive benefit from it and to own it.^2,3

According to the Mishnah, chametz that was owned by a Jew during Passover remains forbidden for benefit even after the festival (chametz she-avar alav ha-Pesach). For this reason many people, after Passover, buy grain products only from shops they know sold their chametz or are under non-Jewish ownership.⁴

The ban on chametz on Passover is stricter than the ordinary rules of kashrut: according to the codes, nullification in sixty (bitul be-shishim, see The Kosher Kitchen) does not apply to it, so even a minute admixture renders a dish forbidden.⁵

According to the Mishnah, the obligation to eat matzah can be fulfilled only with five kinds of grain: wheat, barley, spelt, rye (shifon) and oats (shibbolet shu’al); the identification of the last two is debated in modern times. Only these grains become chametz, if they are left to rise after being mixed with water.⁶

Matzah (מַצָּה) is therefore a dough of flour and water baked before it can rise; according to established practice the whole process from mixing to placing in the oven takes no longer than about 18 minutes.⁷

Alongside hand-baked round shmurah matzah, machine-made square matzah is in common use today. Some Hasidic and Orthodox communities prefer hand-baked matzah for the seder.

Bedikat chametz (בְּדִיקַת חָמֵץ): on the evening before 14 Nisan the house is searched by candlelight. This is followed by the Aramaic formula kol chamira, which nullifies all chametz the owner does not know about. According to the Talmud, nullification alone would suffice by Torah law; searching and burning are rabbinic enactments.^{10,11,12,13,14}

Bi’ur chametz (בִּעוּר חָמֵץ): on the morning of 14 Nisan, by a set hour, the chametz found is burned and the nullification is repeated. From then on chametz is neither eaten nor owned. The practical course of cleaning and the seder is described in the entry פסח.¹⁵

Selling chametz (mechirat chametz, מְכִירַת חָמֵץ): supplies that cannot be used up (for example grain alcohol, flour, opened packages) can be legally sold to a non-Jew before the festival and bought back after Passover. In practice the sale is entrusted to a rabbi acting as agent; the chametz is stored in a closed and marked cupboard. The codes recognise the sale if it is genuine.¹⁶

Conservative/Masorti rabbis usually also arrange the sale of chametz; in Reform communities it is rarer, and the emphasis is rather on symbolically removing chametz from the home.

Because dishes absorb chametz during the year, traditional households keep special sets for Passover – again meat and dairy – stored separately for the rest of the year. Those who do not have them can kasher some of their dishes for Passover; the general principles (hagalah, libun, materials) are described in The Kosher Kitchen.

According to the codes, kashering should be done before the time when chametz becomes forbidden (the morning of 14 Nisan); many communities hold a communal kashering of vessels (hagalah) before Passover under a rabbi’s supervision.¹⁹

An ordinary kashrut certificate is not enough: food for Passover carries a special kosher le-Pesach label (Hebrew כָּשֵׁר לְפֶסַח), which guarantees that neither the product nor the production line came into contact with chametz. The certificate often also states whether the product contains kitniyot. On labelling in general see Certification and Hechsher.

Some products (for example fresh fruit and vegetables, some pure raw ingredients) do not require certification according to many authorities; lists are published every year by rabbinates and certification agencies. Medicines and cosmetics are a separate question best discussed with a rabbi and a doctor; never stop taking a medicine on your own.