Rabbi Arthur Waskow
WHAT IS MATZAH? WHAT IS CHAMETZ?
1) TRADITIONALLY, There are TWO commands about bread and Pesach. One is to get ALL "chametz," defined as leavening or souring (e.g. yeast, regular vinegar, fermented beer & wine and liquor), and anything that has not been carefully checked to eliminate them, out of our possession. All breads that take more than 18 minutes to be baked (and thus might rise from yeast in the air or whatever) and/or have any yeast at all in them are included, and thus forbidden. Thus no flattish breads like pita.
The 2nd commandment about this is that we DO eat matzah, at least on the night of 14 Nisan. Legal matzah is a bread baked in 18 minutes or less from flour (wheat or oats or spelt) and water -- nothing else, No flavoring,no fruit juice.
So-called "egg matzohs" are NOT chametz (since baked in less than 18 minutes with no yeast) but DO have stuff other than flour & water, and so are NOT "legal" matzohs for eating at the Seder to fulfill the commandment to eat matzoh. But they can be eaten during Pesach. Thus some people eat them on the day before Pesach when you'r e NOT supposed to eat chametz and are ALSO not yet supposed to eat real matzohs.
2. Long ago, some rabbis of Ashkenazic (Northern European) involvement ruled that rice, corn (when it came along) and beans could be too easily mistaken for grain like wheat, and so vice versa -- people might think wheat was rice and so eat it. Therefore these things should not be eaten either. Sephardic (southern European, Mediterranean) and Mizrachi (Middle Eastern, Far Eastern / Oriental) rabbis thot this was foolish.
Thus these two groups of Jews -- Ashkenazim & everybody else -- have different habits. Nowadays, some Masorti (conservative) rabbis in Israel have ruled that the prohibition was silly in the 1st place and now is often used by Ashkenazic Ortho & Charedi Jews as a put-down of Sephardim, and these rabbis have encouraged Ashkenazim to drop the prohibition.
by Rabbi Arthur Waskow
Director, The Shalom Center.