Can matza be made out of rice?
While there is an opinion in the Gemara that rules that rice can become ḥametz (leaven) and similarly, can be baked into matza, this position is rejected by the Mishna (see Massekhet Pesaḥim, daf 35). On today’s daf a different, but related question is raised – can matza be made out of wheat flour that is mixed with rice flour? The Gemara quotes a Mishna in Massekhet Ḥalla (3:7) that clearly rules that if dough that is made from a mixture of wheat and rice, as long as the mixture tastes like wheat, the matza can be used to fulfill the mitzva on Passover.
Rabbeinu Tam understands this to be similar to the rule that when the taste from a forbidden food can be sensed in a mixture we consider the entire mixture to be forbidden. The Ra’avad argues that even though the wheat flour in this mixture is significant inasmuch as its taste is present, still there will have to be a sufficient amount of wheat flour – a ka-zayit (olive’s worth) – in what the person ate if he is to fulfill his mitzva of eating matza on Pesaḥ. In contrast, the Ramban accepts the approach of the Talmud Yerushalmi (Ḥalla 1:1) that explains that the issue at hand is not the taste of the mixture. What happens in this case is that the wheat flour causes the rice flour to ferment and become ḥametz, something that is not true when wheat flour is mixed with other things. Such a mixture can be baked into matza, as well.
The rice discussed by the Gemara is Oryza sativa, an annual cereal grain that grows in marshy areas or flooded fields. Rice originated in the Far East, but was already brought to Israel in the Mishnaic period. It is usually used as a cereal, and it is difficult to make bread out of it because it lacks bonding agents that would hold the bread together. Nevertheless, it was often mixed with other grains to be used in bread production. The Sages differed with regard to the halakhic status of rice – its proper blessing, whether it can become ḥametz and matza, and so forth.