Eating Matzah Labeled “Not Kosher for Passover" After Rosh Chodesh Nisan

I follow the minhag of not eating matzah beginning Rosh Chodesh Nissan. Am I permitted to eat matzah which is labeled “Not Kosher for Passover”?

(A Subscriber’s Question)

Matzos which are labeled “Not Kosher for Passover” are made without a full-time mashgiach present during production, and the water used in kneading the dough is not mayim she’lanu (specially drawn water). Though we would not eat these matzahs on Pesach, it is not certain that the matzahs are absolute chametz. Mishnah Berurah 471:12 writes that the Rabbinic prohibition to not eat matzah on Erev Pesach, applies even to matzah that has folds or bubbles, since such matzahs are of questionable status, and they are not absolute chametz. This would imply that “Not Kosher for Passover” matzahs may not be eaten Erev Pesach, since these matzahs are also of questionable status. Nonetheless, Rav Schachter, Shlita, maintains that the definition of matzah with respect to the minhag (practiced by some) not to eat matzah beginning Rosh Chodesh is not the same as the definition of matzah relative to Erev Pesach. Shulchan Aruch (Y.D. 214:1) writes that a minhag is a form of a vow. Vows are interpreted in accordance with common usage of language. Since most people consider “Not Kosher for Passover” matzahs to be chametz, they may be consumed until Erev Pesach.

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