Gemara

(Mishnah): All Menachos are Matzah, except for the Chametz loaves brought with Todah, and Shtei ha'Lechem, which are Chametz.

53a (Beraisa): We do not use apples to ferment (Shtei ha'Lechem or Lachmei Todah);

R. Chanina ben Gamliel permits.

Suggestion: The following Mishnah is like R. Chanina;

(Mishnah): If a Terumah apple was minced and put into a dough and fermented it, it is forbidden (to Zarim).

Rejection: It is even like Chachamim. Granted, it does not become proper Chametz, but it does become Chametz Nuksheh.

57a (Beraisa - R. Yosi ha'Galili): "Asher Takrivu" includes Minchas Nesachim. (One may not ferment it);

Question: Minchas Nesachim is kneaded only with oil. Flour with Mei Peros will never ferment!

Answer (Reish Lakish): R. Yosi ha'Galili holds that one may knead Minchas Nesachim (also) with water, and it is Kosher.

Pesachim 35a (Reish Lakish): One is not Chayav Kares for a dough kneaded with wine, oil or honey.

(Rav Idi bar Avin) This is because Mei Peiros (fruit juice) do not ferment.

36a (Beraisa): During Pesach, one may not knead a dough with wine, oil or honey;

R. Shimon ben Gamliel says, if one did so, one must burn it immediately.

Chachamim say, it may be eaten (if it was baked promptly).

R. Akiva says, I once made a dough for R. Eliezer and R. Yehoshua (during Pesach) with wine, oil and honey, and they did not comment.

Even though one may not knead with them, one may smear the dough after it is arranged into loaves;

This is according to the first Tana

Chachamim say, one may smear only with things with which one may knead.

R. Yehoshua (to his children): Do not knead for me with milk (alternatively - honey) on the first day.Afterwards, you may do so.

39b (d'Vei R. Shila): Vatika (a tart) is permitted.

Question (Beraisa): It is forbidden.

Answer: If it is made with oil and salt it is permitted. If it is made with water and salt it is forbidden.

40a (Abaye): One may not roast two ears of grain together, lest juice leave one and be absorbed in the other, and it will become Chametz.

Objection (Rava): If so, even one should be forbidden, lest juice leave one end and be absorbed in the other end, and it will become Chametz! Rather, both of these are permitted, because Mei Peiros do not ferment.

(Abaye): If grain was parched in a jug in an oven, if the mouth faces down (so juice that exudes will fall out), it is permitted. If the mouth faces up, it is forbidden.

(Rava): In both cases it is permitted. Mei Peiros do not ferment.

Rishonim

Rif (Pesachim 10a): Presumably, the Halachah follows R. Akiva, for R. Yehoshua ben Levi holds like him. He permitted his children to knead with milk after the first day. Surely, the Beraisa discusses oil with water, for Kituf is kneading with water and smearing with oil. The first Tana forbids kneading with the same things (wine, oil or honey) that he permits for Kituf. R. Gamliel and Rabanan forbid kneading and Kituf with them.

Rebuttal (Rosh Pesachim 2:13): Perhaps Rabanan (the first Tana) forbid kneading (with Mei Peros) even without water, for they hold that Mei Peiros without water ferment, like Abaye says. Kituf (with Mei Peros) is permitted even with water, for it is only a little. R. Akiva permits only (kneading) only with Mei Peiros without water.

Rif (ibid.): If not for R. Yehoshua ben Levi, an Amora, who followed R. Akiva in practice, we would say that the Halachah follows the Rabim, i.e. Rabanan. However, since R. Yehoshua ben Levi, who is Basra, acted like R. Akiva, this is the Halachah. We do not find an Amora who argues with him. Also, the Gemara brings a proof from him. This shows that the Halachah follows him. I saw some Rabanan forbid on the first day and afterwards, both kneading and Kituf, like Rabanan. Others permit.

Rosh (ibid.): The Rif holds that Mei Peiros do not ferment even with water. This is difficult, for Vatika made with oil and salt is permitted. If it is made with water and salt it is forbidden. This shows that Mei Peiros with water ferments.

Korban Nesan'el (100): The (Rosh and) Tur hold(s) that salt is considered Mei Peros. (Ra'anach (2:74) initially said that Tosfos holds that salt is like water, but retracted.) Do not say that we permit Vatika with oil and salt when he guarded from Chimutz, for if so we should permit also with water and salt!

Note: Mishnah Berurah (462:24) says that sea salt is like water, but many say that salt mined from the ground is like Mei Peros.

Rosh (ibid.): Also the Gemara of Minchas Nesachim proved this. Therefore, I agree with those who rule like Chachamim. The Yerushalmi connotes that Mei Peros by themselves ferment. Cases occurred with barley thrown into wine, flour in honey, and wheat in oil. In each case an Amora forbade. Perhaps all of them hold like Abaye, who says that Mei Peiros without water ferment. We hold like Rava, that it is permitted.

Rambam (Hilchos Chametz 5:2): If the five grains were kneaded with Mei Peros without any water, they will never become Chametz. Even if one leaves it the entire day until the dough inflates, one may eat it. Mei Peros do not ferment. They only cause spoilage. If any water mixed in, they ferment.

Ra'avad: Not all agree that grain with Mei Peros will never ferment. It does not become proper Chametz, and there is no Kares for it, but it become Chametz Nuksheh, and it is forbidden.

Magid Mishneh: Most Meforshim say that there is no Isur at all. They brought proofs. The Ra'avad holds like Rashi; Tosfos and Ba'al ha'Itur brought clear refutations. Also the Ge'onim hold that Mei Peiros do not ferment. This is even l'Chatchilah. There is no concern. This is the custom; it is primary.

Rosh (ibid.): 'There is no Kares' implies that it is not full Chametz, but it is Chametz Nuksheh, and one is lashed for it. The Beraisa on 36a says that it must be burned immediately. However, we permit grain parched in a jug and Vatika with oil and salt, because Mei Peros do not ferment. R. Tam explains that Mei Peros without water do not ferment. When there is also water, it becomes Chametz quickly. Minchas Nesachim can become Chametz only if water is added (Menachos 57a). If a minced apple was put into a dough and fermented it, it becomes Chametz Nuksheh. This is if it was already kneaded with water, just like we say that Reish Lakish discusses when it was kneaded also with water. Do not say that Reish Lakish discusses when no water was added, and he disagrees with Rava (who says that Mei Peiros do not ferment). If so, what forced Reish Lakish to answer that R. Yosi ha'Galili permits kneading Minchas Nesachim with water? If it becomes Chametz Nuksheh even without water, this is Pasul for Menachos! The case of the minced apple proved this. (It may not be used to ferment Shtei ha'Lechem or Lachmei Todah because it causes Chametz Nuksheh.)

Poskim

Shulchan Aruch (OC 462:1): Mei Peros without water do not ferment at all. During Pesach one may eat Matzah kneaded with Mei Peros, even if it delayed the entire day (before it was baked).

Beis Yosef (DH ul'Inyan): The custom is to knead with Mei Peiros without any water, without any concern for Chametz. It does not ferment even if it is left the entire day.

Beis Yosef (DH v'Hashta): The Tur wrote that some forbid kneading with Mei Peiros with water, but permit Kituf. It seems that this is like the first Tana, according to the opinion that he discusses wine, oil or honey with water, but without water, they may be used even for kneading.

Mishnah Berurah (2): If there is even a tiny amount of water, they ferment.

Kaf ha'Chayim (1): The Shulchan Aruch rules like the opinion that Mei Peros without water do not ferment at all. The Magid Mishneh says that most hold like this. Sefer ha'Manhig says that we cannot decide between the opinions. One should be stringent like all of them. Rashi forbids Mei Peiros even without water. Ra'anach says that one should be stringent to guard from Chimutz even when using pure Mei Peros, like for a regular dough kneaded with water. Keneses ha'Gedolah says that people are not stringent; my father would eat a dough kneaded with Mei Peros only on the last (eighth) day, due to concern lest Mei Peiros alone ferment. Tumas Yesharim was stringent not to knead with Mei Peiros even without water, even if he would guard from Chimutz like for a regular dough. Most Poskim rule like the Shulchan Aruch; this is the custom of all Sefardim. However, one one who kneads with Mei Peiros even without water should guard from Chimutz.

Rema (4): In these lands, our custom is not to knead with Mei Peros. Even to smear the Matzos with Mei Peros we do only after they are baked while they are still warm.

Magen Avraham (4): Why does he say 'even'? Smearing is a bigger problem, for then there is also the water with which it was kneaded! He says 'even Kituf' for it is only a little.

Kaf ha'Chayim (44): Even though they will be put into the oven immediately after smearing, it is forbidden.

Mishnah Berurah (15): L'Chatchilah we are concerned for the Poskim who say that Mei Peros by themselves ferment quickly. Also, we are concerned lest a little water became mixed with them. Then, all agree that they ferment.

Kaf ha'Chayim (41): The Birkei Yosef says that our custom is to use only wine (without water), and to do it as quickly as possible. In this way, we fulfill all or most of the opinions. Some Sefardim have the custom is not to use Mei Peros at all in Matzah.

Mishnah Berurah (18): The custom is, even if they were kneaded and baked immediately, we do not eat it on Pesach. We leave it for after Pesach.

Rema (ibid.): One may not deviate, except in pressed circumstances for a sick or old person who needs it.

Mishnah Berurah (19): He should bake them immediately, and use only Mei Peros without water. We do not permit l'Chatchilah with water even in pressed circumstances.