Mishneh Torah, Leavened and Unleavened Bread 5

Sugya Map

• Core Issue: Defining the boundary between chimutz (leavening) and sirchon (decay) in the five species of grain and the legal status of liquids (water vs. mei peirot).
• Nafka Mina:
  • Determining the status of "Matzah Ashirah" (rich matzah) and whether fruit juices can render dough chametz in the presence of even trace amounts of water.
  • The validity of using various grains (rye, oats) and the permissibility of cooking processes (boiling vs. baking).
• Primary Sources: Pesachim 35a-42a; Mishneh Torah, Hilchot Chametz U’Matzah 5.

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Text Snapshot

Rambam, Hilchot Chametz U’Matzah 5:1:

"הדברים אמורים כשלא נתערב בהן מים כלל, אבל אם נתערב בהן מים - הרי אלו מחמיצין, ואפילו נתערב בהן מים מעט." (These matters apply when no water whatsoever is mixed with them, but if water is mixed with them, they become leavened, even if only a small amount of water is mixed in.)

Leshon Nuance: The Rambam distinguishes between mei peirot (fruit juices) which trigger sirchon (decay) and water which triggers chimutz. The term "no water whatsoever" (lo nit'arev bahen mayim klal) is the fulcrum. The dikduk here suggests an absolute threshold; the inclusion of even a "drop" of water shifts the chemical reaction from benign decay to the prohibited fermentation of the chameishat minei dagan (five species).

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Readings

1. Sefer HaMenucha (Rabbenu Manoach)

Rabbenu Manoach addresses the ambiguity of mei peirot in the context of the custom to avoid kitniyot. He argues that the prohibition against kitniyot (legumes) is not rooted in a fear of chimutz—which he asserts is physically impossible for rice or beans—but rather in a socio-halachic concern for simcha (joy) during the festival. His chiddush is the distinction between the objective halacha of chimutz and the minhag (custom). He notes that even if a community treats kitniyot as forbidden, this does not grant the substance the status of chametz in the eyes of the Torah; it remains a protective fence (siyag) unrelated to the actual fermentation process.

2. Tzafnat Pa'neach (Rogatchover Gaon)

The Rogatchover focuses on the Tzafnat Pa'neach analysis of the mixture of the five species. He asks: what happens if you mix two of the five species? He posits that if a new dough is formed from a mixture, it might lose its individual status and become a "new entity" (panim chadashot), potentially exempt from the laws of challah or even chimutz. He cross-references the Jerusalem Talmud, Challah 1:1, suggesting that the fermentation process is predicated on the identity of the grain. If the mixture creates a hybrid substance, the chemical path to chimutz is altered. This is a radical ontological approach to kashrut—suggesting that by manipulating the substance of the grain through blending, one might move outside the category of chameishat minei dagan.

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Friction

The Strongest Kushya: If mei peirot do not cause chimutz, why is "Matzah Ashirah" (dough kneaded with juice) treated with such extreme stringency, often prohibited for the Seder entirely? If the Rambam is correct that it cannot become chametz, the prohibition seems to lack a logical basis in the mechanics of fermentation.

The Terutz: The terutz is twofold. First, the Shulchan Aruch (Orach Chayim 462:4) explains the Rema's position: the fear is not that the juice itself ferments, but that it is impossible in a practical, domestic setting to ensure that not a single drop of water (mayim) has infiltrated the juice or the flour. Because mei peirot mixed with even a trace of water accelerates fermentation faster than water alone, the Sages applied a blanket stringency to prevent error. Second, there is the mitzvah of "Lechem Oni" (bread of affliction) Deuteronomy 16:3. Even if the dough is technically not chametz, "rich" matzah fails the requirement of being "poor man's bread." Thus, the restriction is a combination of gzeirah (rabbinic decree) against accidental water contamination and a theological requirement to maintain the character of the Seder meal.

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Intertext

The Rambam’s treatment of grain sinking in water Pesachim 40b parallels the rules of taharat hamishpacha regarding the collection of water. Just as stagnant water (mayim she-eino mitaher) can be problematic in ritual immersion, stagnant water in contact with grain creates a "pool" for fermentation. The Sifrei on Deuteronomy 16:3 emphasizes the "watching" (shemurah) of the matzah. The intertextual link here is the concept of shmirah: one must guard the grain from the moment of harvest. The Mishneh Torah elevates the physical act of "keeping" from a passive state to an active, intentional process—the grain must be watched for the sake of the mitzvah, not merely kept dry.

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Psak/Practice

In contemporary halacha, the psak follows the Mishnah Berurah (Orach Chayim 462):

1. Matzah Ashirah: Ashkenazic practice is to prohibit it for the Seder and for general use on Pesach, except for the elderly or infirm who cannot digest standard shemurah matzah.
2. Kashering: The psak is strictly to perform hagalat keilim (purging) for metal, but earthenware is generally considered "un-kasherable." The modern heuristic is to use dedicated Pesach-only cookware to avoid the sfeikot (doubts) regarding the absorption levels in modern materials.

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Takeaway

Chimutz is not merely a biological fact; it is a legal category defined by the presence of water and the passage of time. The Rambam teaches that while chemistry (decay vs. fermentation) provides the framework, our halachic vigilance—the "keeping" of the matzot—is what sanctifies the process.