Q. Our minhag is not to eat matzos thirty days before Pesach. Since I only eat shemura matzos during Pesach, can I eat now regular machine matzos. Can I eat gebrocht matzos in soup or matzebrai, since we don’t eat gebrochts on Pesach?
A. Rema (O.H. 471: 2) rules that on Erev Pesach it is prohibited to eat matzos that can be used for the seder. Mishna Berura (ibid. 12) adds that some accustom not to eat matzo from Rosh Chodesh Nissan.
Mishnas Yaakov (3: 471), Kitzur Hilchos Pesach, Nitei Gavriel (1: 2: 10) and others maintain that the minhag is thirty days before Pesach. Igrois Moshe (O.H. 1: 155) explains that this is the time we begin the preparations for Pesach.
However, as mentioned the prohibition applies only to the matzo that one can consume at the seder night.
Horav Shlomo Miller’s Shlit’a opinion is that if the eating of matzo is necessary for diet purposes, one can put the well marked matzo in contact with bread and thus make it inedible for Pesach. Then he may consume it even after Rosh Chodesh until Erev Pesach. when it would be prohibited. The same may apply to gebrochts.
Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit’a