Is it permissible to take Masa on Pesah and put it in liquid, such as in soup, or a dip? And may one place sauce on one’s Masa?
The Shulhan Aruch rules explicitly (Orah Haim 463:3) that one may boil fully baked Masa in water on Pesah. However, the Sha’areh Teshuba observes the custom followed by some individuals to refrain from placing Masa in liquid on Pesah. The reason for this custom is the concern that there might be some dough in the Masa that had not been fully baked, and this dough will become Hametz if it comes in contact with liquid, particularly if the liquid is hot. This custom is noted by several Poskim, including Rav Schneur Zalman of Liadi (the first Rebbe of Lubavitch, 1745-1813), and brought by the Mishna Berura (Rav Yisrael Meir Kagan of Radin, 1839-1933). A number of Ashkenazic communities follow this practice and refrain from what they call "Gebrukst" (literally, "soaked") – Masa that has come in contact with liquid.
Sepharadim, however, did not accept this stringency, and thus it is entirely permissible for Sepharadim to place Masa in liquid on Pesah. This is especially true nowadays, when our Masa is very thin, which makes it virtually impossible that there would be unbaked flour in the Masa. The Shulhan Aruch ruled leniently with regard to the Masa customarily eaten in his time, which was thick, such that there might have been a possibility of some dough being left unbaked; certainly, then, there is no reason for concern when it comes to the thin Masa that we eat.
However, Hacham Bension Abba Shaul (Jerusalem, 1924-1998), in his Or Le’sion (vol. 3, 11:13), writes that there is room to be stringent in this regard when eating machine-made Masa. He explains that in the factories which produce machine Masot, flour is spread throughout the air of the room. Hacham Bension observed that one who walks inside the factory comes out covered in white from the flour particles that fly about in the air. Now the Shulhan Aruch (Orah Haim 459:6), based on the Terumat Ha’deshen (Rav Yisrael Isserlein, 1390-1460), rules that when baking Masot, one should not add flour onto the surface of the dough after the dough has been kneaded and prepared for baking. As this added flour is not mixed into the dough, it might not be properly baked in the oven, and could then potentially become Hametz. Hacham Bension thus writes that since flour particles fly about in the factory as the machines mix the dough, some flour is likely to fall onto the surface of dough after the kneading. Therefore, he writes, those who wish to be stringent should refrain from placing machine-made Masa in liquid, because the flour which fell onto the dough before it was baked might not have been fully baked in the oven. Hacham Bension acknowledges that in all likelihood, even this additional flour becomes immediately baked in the oven, such that there is no concern. Nevertheless, he writes that although it is permissible to place machine Masa in liquid on Pesah, there is room to be stringent and refrain from placing machine Masa in warm liquid, which could cause unbaked flour to become Hametz. And if one did mix machine Masa with hot liquid, he should eat it quickly, before the unbaked flour has a chance to become Hametz.
It should be noted that Hacham Ovadia Yosef, in Hazon Ovadia, draws no distinction between hand-made Masa and machine-made Masa in this regard, indicating that it is entirely permissible to place even machine-made Masa in liquid on Pesah.
Summary: Some Ashkenazic communities have the custom not to place Masa in liquid on Pesah, due to the concern that there may be some unbaked flour in the Masa which will become Hametz if it comes in contact with liquid. Sepharadim did not accept this stringency, and may place Masa in liquid on Pesah. However, according to one opinion, it is admirable even for Sepharadim to avoid placing machine-made Masa in hot liquid, and, if some machine Masa did come in contact with hot liquid, to eat it right away. Others disagree, and maintain that there is no need for Sepharadim to be stringent in this regard at all.