A Matter Of Inflation
‘Since It’s Baked, It Expands’
The Rema, citing the Maharil (Orach Chayim 461:5), famously rules that a matzah that comes out of the oven inflated is not kasher l’Pesach (see Chok Yaakov, s.k. 9).
Many poskim do not agree with this chidush. The Taz testified that his father-in-law, the Bach, discussed this type of matzah at length but “never forbade it” (see Magen Avraham, ibid, s.k. 13). The sages of Venice also never understood why inflated matzah should be forbidden (Chok Yaakov, ibid; notes an item can only be chametz when it is left to rise before it is baked).
The Show Bread Also Expanded
Our Gemara states that when the showbread – which was matzah – was taken out of the oven in the Mishkan and Beis HaMikdash, it was not returned to the container used to form the dough since it increased in size while it was baked.
The Ramaz (Responsa, 52), specifically cites our sugya, writes: “and another clear proof, as we learn in Menachos (94a): ‘as soon as it was baked, it expanded.’ So we see that the showbread inflated.” He therefore rules that inflated matzah is kasher l’Pesach.
Two Possibilities of Inflated Matzah
Rabbi Shmuel Abuhav, zt”l, tried reconciling the Maharil’s opinion with our sugya. In his Dvar Shmuel (234 and 374), he writes, “Raised matzah can come about in one of two ways. Sometimes the dough divides in half during baking and a hollow appears between the halves, and other times the entire dough expands uniformly” (see Bach and Mishnah Berurah, s.k. 33).
Our Gemara, writes Rabbi Abuhav, concerns the showbread matzah, which expanded but did not divide in half. This matzah is allowed. What is forbidden is what the Maharil forbade: matzah that divided in half. The Maharam of Lublin likewise permits raised matzah but forbids divided matzah.
A Third Possibility
The Taz (Magen Avraham, s.k. 13) maintains that only matzah that rose like a mountain (i.e., unevenly) is forbidden because it might have become chametz at the point where it rose. Uniform expansion, though, is fine (see Pri Megadim in Mishbetzos Zahav, s.k. 6, and Shaarei Teshuvah, end of siman). According to this opinion, our Gemara discusses matzah that expanded naturally and evenly whereas the Maharil discusses matzah that rose only partially.
Another possibility is as follows: The Gemara may be talking about matzah that expanded sideways (which makes sense because, if it expanded upwards, why couldn’t the same contains be used?) while the Maharil is talking about matzah that expanded upwards.
The Shaarei Teshuvah (s.k. 5) discusses this question at length and concludes that Rabbi Abuhav understood the Gemara to mean that the matzah expanded uniformly in all directions. The Ramaz (ibid.) indicates that the showbread only expanded upwards and to such an extent that there was a need to put it in containers with higher sides. Since it was soft, its unique form would be ruined otherwise.
Well, Is It Kosher ?
In practice, the custom for many generations is to forbid all kinds of inflated matzah, both matzah that expanded uniformly and matzah divided lengthwise (Magen Avraham and Chok Yaakov, ibid; Mishnah Berurah, s.k. 33). Some, however, rule differently for countries where matzos are very thick (Responsa Dvar Shmuel, ibid; Shaarei Teshuvah, s.k. 6; Mishnah Berurah, s.k. 35).
The Aruch HaShulchan (461:12) testifies: “We never forbade inflated matzah. Thin matzos that become inflated are known to usually occur because of insufficient perforation or due to the strength of the fire.” The Mishnah Berurah doesn’t rule on the issue; see Piskei Teshuvos. We perforate the dough before baking, though, precisely to avoid inflation issues.
In a Pack of Matzos
If an inflated matzah becomes mixed in a pack of matzos, does it forbid the entire package as well as hot utensils it touches? The Mishnah Berurah (ibid.) writes: “It seems that, at any rate, we should behave leniently if the inflated matzah is mixed in a majority of 60, especially with thin matzos such as ours. Even if one wants to behave strictly, one should not be strict concerning mixtures.”