Several specific requirements apply to the Matza eaten for the Mitzva at the Seder on Pesach. Firstly (as discussed in a previous Halacha), this Matza should preferably be produced from wheat that had been carefully watched from the moment it was harvested; this Matza is referred to as "Matza Shemura," and one must endeavor to purchase specifically this kind of Matza for the Seder.
Additionally, the Matza eaten at the Seder must have been baked with the Mitzva of eating Matza in mind. Therefore, the workers who bake Matzot in the factories declare at every stage in the process, "Le'shem Matzat Mitzva" ("For the purpose of Matza for the Mitzva"). This requirement has generated considerable discussion among the authorities concerning the use of machine-made Matzot at the Seder. Since the entire process is performed mechanically, it is questionable whether or not such Matza can be said to have been baked with the Mitzva in mind. Therefore, one should preferably use specifically hand-baked Matza for the Mitzva of eating Matza at the Seder. Nevertheless, Chacham Ovadia Yosef rules in his work Chazon Ovadia (Laws of Pesach, p. 78) that if one cannot obtain hand-baked Matza, he may fulfill his obligation with machine Matza, provided that it was baked by a God-fearing Jew who declared "Le'shem Matzat Mitzva" when pressing the button to operate the machine. It must be emphasized, however, that in locations such as New York where hand-baked Matza is readily available, one should not rely on this leniency and should instead make a point of using hand-baked Matza for the Seder.
The Matza eaten at the Seder should ideally be baked from wheat. People with an allergy to wheat may fulfill their obligation with Matza baked from oats or spelt, provided that all the other conditions for the Matza are met, namely, the grain was protected from water from the moment it was harvested, and it was baked with the Mitzva of Matza in mind. (See Chazon Ovadya, page 76.)
Before eating Matza at the Seder, one recites two Berachot: the Beracha of "Ha'motzi," which is recited over all types of bread, and the special Beracha of "Al Achilat Matza," which refers to the Mitzva of eating Matza at the Seder. It should be noted that this Beracha of "Al Achilat Matza" is recited only before one eats his first piece of Matza at the Seder. During the rest of Pesach, eating Matza does not constitute a special Mitzva, and therefore one recites only the Beracha of "Ha'motzi," and not "Al Achilat Matza." (See Chazon Ovadya, page 86.)
Some people have the practice not to dip Matza in water during Pesach, out of concern that this may cause the Matza to become Chametz. This is not the practice of the Sepharadim. Nevertheless, if one took upon himself this stringency without stipulating that he does so "Beli Neder" (without accepting a formal vow) and then wishes to discontinue this practice, he must first perform "Hatarat Nedarim" (annulment of vows). It is therefore proper to ensure before taking on such a practice to explicitly stipulate that one does not intend to formally accept this practice on a permanent basis. (See Chazon Ovadya, page 220.)
There are those who observe the even stricter measure of refraining from eating Matza altogether after the first night of Pesach, out of concern that the Matza may be Chametz. These people eat the minimum required amount of Matza at the Seder and then refrain from eating Matza throughout the rest of the holiday. Chacham Ovadia Yosef (Chazon Ovadia – Laws of Pesach, p. 221) opposes this custom, and rules that it is proper to eat Matza throughout Pesach, particularly on Shabbat, when there is an obligation to eat three meals with bread (which on Pesach can of course be fulfilled only with Matza).
Some people observe the practice to eat only Matza Shemura throughout the holiday of Pesach, and not merely at the Seder. Although this stringency is not required according to strict Halacha, it is a laudable practice to follow. Once again, a person who took on this practice without stipulating that he does so "Beli Neder" must perform "Hatarat Nedarim" if he then decides to discontinue the practice. Therefore, one who decides to begin eating only Matza Shemura even after the Seder should explicitly declare that he does not take on this measure of stringency permanently.
Summary: At the Seder, one should use specifically hand-made Matza Shemura. If one cannot obtain hand-made Matza, he may use machine Matza provided that it was baked by a God-fearing Jew familiar with the relevant laws. People allergic to wheat may use Matza baked from oats or spelt. It is proper to eat Matza throughout Pesach, and not merely at the Seder, but the Beracha of "Al Achilat Matza" is recited only at the Seder. Although one may eat Matza that is not Shemura after the first night of Pesach, it is a laudable measure of stringency to eat only Matza Shemura throughout Pesach, though one who accepts this practice should stipulate that he does not formally accept it as a permanent, formal vow.
