Some have the custom not to eat Massa that has come in contact with water. The concern is that there may be flour that was not fully baked inside the Massa that will become Hametz upon contact with water. This stringency is brought by the Mishna Berura (Rav Yisrael Meir Kagan of Radin, 1839-1933) in Siman 559, as well as by the Shaare Teshuva and the Shulhan Aruch HaRav. However, many great Ashkenazi authorities would eat soaked Massa. For example, there is testimony that the Vilna Gaon (Rav Eliyahu of Vilna, 1720-1797) ate it in front of his disciple Rabbi Haim of Volozhin. In general, Ashkenazim following the Lithuanian tradition do not adopt this custom, whereas Hassidim are stringent in this matter.
Even those who are stringent, allow soaking Massa in "Meh Perot"-fruit juice, since these liquids do not create Hametz. This would also include wine and milk. However, the Steipler Rabbi Yaakov Yisrael Kanievsky, Benai Brak 1899–1985), was stringent even with regard to Meh Perot.
Hacham Bension and Hacham Ovadia state that the custom of the Sepharadim is clearly not to be stringent. Once Massa is baked, it cannot become Hametz. This is especially true with regard to today’s Massa, which is baked very thin and crisp, like a cracker.
It should be noted that Hacham Ben Sion in his Ohr Le’sion adopted the stringent custom with regard to machine-made Massa. He was concerned that the cloud of pulverized flour in the air of the factories may land on the baked Massot and become Hametz upon contact with water. However, the Ner Sion, written by his student in 2012, states that Hacham Ben Sion later retracted his opinion, upon re-inspecting the Massa factories.
SUMMARY
The custom of Sepharadim is to permit eating soaked Massa on Pesah.
