The Matzah one uses to fulfill one’s obligation on the night of the Seder must be made from wheat which was guarded from the time of harvest. This is what is commonly referred to a “Shemura Matzah,” i.e., Matzah made from wheat guarded from the time of its harvest to make sure not even a drop of water came in contact with it. It is especially preferable that these Matzot be hand-made for the sake of Matzah being used for the Mitzvah. Since there are many issues that can easily arise and bring the Kashrut of the Matzah into question, one should take care to purchase Matzah only from a bakery that is under the supervision of a reputable Kashrut organization. Nowadays, thank-G-d, there hand-made (round) Matzah that are made especially for the Seder under strict rabbinical supervision are readily available and one should try to purchase such Matzah for the Pesach Seder.
“Al Achilat Matzah”
The blessing of “Al Achilat Matzah” should only be recited on the Seder night (both nights outside of Israel). Nevertheless, on the rest of the days of Pesach when eating Matzah is not obligatory, this blessing is not recited, as the verse states, “On the fourteenth day of the month in the evening shall you eat Matzot.”
The Amount of Time to Eat
The Matzah must be eaten within the amount of time it takes “to eat half a loaf of bread.” One should therefore preferably eat the Kezayit of Matzah within four minutes. If one cannot do so, one should eat it within no more than seven-and-a-half minutes.
If One Ate Without Reclining
We have already discussed that the Matzah eaten on the Seder night must be eaten while reclining to one’s left side. If one ate Matzah without reclining, one must eat more Matzah while reclining. Nevertheless, one should not recite the “Al Achilat Matzah” blessing again. (Yalkut Yosef- Pesach, page 462)
We have also explained that women are just as obligated to recline during the Seder as men are. Nevertheless, if a woman mistakenly ate Matzah without reclining, she may rely on the Poskim who rule that women are not required to recline, and she need not eat again. (Yalkut Yosef- Pesach, Volume 3, page 470)
Not Speaking Until One Has Eaten a Kezayit
Since the Mitzvah of eating Matzah on the Seder night refers to eating a Kezayit, as we have explained above, the “Al Achilat Matzah” blessing refers to eating a complete Kezayit of Matzah. One should therefore not speak at all until one has eaten the entire Kezayit while reclining. Nevertheless, if one spoke after eating some of the Matzah, one should not repeat the blessing since one has already begun the Mitzvah. (Chazon Ovadia- Pesach, page 68)
Warming the Matzah
One may warm up the Matzot before eating them on the Seder night. There is no distinction hard or soft Matzot regarding this law.
The obligation to eat Matzah on the Seder night is a positive Torah commandment and thus, even those with gluten sensitivities (such as those suffering from celiac disease) must eat Matzah on this night. Nevertheless, since eating regular Matzah may cause them great pain and discomfort, they should prepare reduced-gluten or gluten-free Matzot (such as spelt or oat Matzah) ahead of time for use during the Seder.