Gemara

(Shmuel): Blood leaves the meat only if it is salted very well and rinsed very well.

93a: If raw meat is very red (because the animal was hit while alive, and blood gathered), if it is cut and salted, it may even be cooked in a pot;

Alternatively, it suffices to roast it on a spit, for the blood will exude.

Menachos 21a - Question: Why do we need a verse to teach that one need not salt blood (offered on the Mizbe'ach)? Salted blood is not considered blood!

(Ze'iri): One is not liable for eating cooked blood.

(Rav Yehudah citing Ze'iri): One is not liable for eating salted blood.

Answer: One might have thought that only a small amount of salt is put on. (This is not like cooking.) The verse teaches that it is not salted at all.

(Beraisa) Suggestion: Perhaps "ba'Melach" teaches that Tevonehu!

Rejection: It says "Timlach."

Question: What does 'Tevonehu' mean?

Answer #1 (Rabah bar Ula): Yisbonenu (put a great amount), like Teven (straw) in mud.

Objection (Abaye): If so, the Beraisa should have said Yisbonenu!

Answer #2 (Abaye): One must make like a Binyan (building of salt).

Objection (Rava): If so, it should have said "Yivnenu"!

Answer #3 (Rava): One must Yevonenu.

(Rav Ashi): The Beraisa suggested that any amount enough to give Ta'am (taste) suffices, just like a bit of understanding gives Ta'am (sound reason) to people. "Timlach" teaches that this is not so;

Rather, one puts (much) salt on each side of the limb and offers it.

(Abaye): The same applies for (salting meat to be cooked in) a pot.

Rishonim

Rosh (8:43,44): Shmuel taught that blood leaves the meat only if it is salted very well and rinsed very well. One must spread much salt, so no place is left without salt. One must salt chickens or geese also inside. After it delayed the time for roasting, the custom is to wash it twice. The first time removes the salt and blood, and the second removes the dirt from the remains of the first water.

Ran (Sof 30b): One must salt meat on both sides. This is like the texts in Menachos that say 'the same applies for a pot.' Therefore, one who salts a kid or chicken must salt inside and out. However, b'Di'eved, even if he salted only one side, or if a piece was salted only on one side, it is permitted. Salting on both sides suffices even for the thickest piece. If we forbid whenever only one side was salted, even for a thin piece, how does cutting help for a thick piece? Rather, we require both sides only l'Chatchilah.

Poskim

Shulchan Aruch (YD 69:4): One spreads salt on the meat so that no place is left without salt. He salts so much that it is too salty to eat. One need not put more salt than this.

Gra (20): In Menachos, Rashi explains that salting is like cooking. Therefore, one puts much salt (so that the blood will be like cooked blood, which the Torah did not forbid). Tosfos (112a DH Hani) says so.

Gra (21): We learn from Menachos that one need not salt so heavily.

Shulchan Aruch (ibid.): He salts it on both sides. One must salt birds also inside.

Gra (22): Shmuel said 'Yafeh Yafeh' (very well), which connotes both sides, or inside (and outside) birds.

Beis Yosef (DH uv'Ikar, citing the Rashba): To salt meat for cooking, one puts salt on both sides. He salts (one side), flips it over and salts (the other side). He salts it well. He need not put so much salt that it is totally covered and like a building. It suffices to salt it well, so it is too salty to eat, until it emits the blood. It seems that it is merely the ideal Mitzvah to salt on both sides. Perhaps if one salted only one side, or it was inconvenient to do so, e.g. salting chickens or geese (one cannot make the salt stick to all sides of the interior unless he cuts them or fills the interior with salt, like stuffing), it is permitted. This is reasonable. A thin piece of meat should not be more stringent than a thick slab a Tefach thick. It suffices to salt the latter on both sides. What removes the blood inside? There is no limit (how thick a slab may be).

Beis Yosef (ibid.): The Rashba holds that l'Chatchilah, one must salt both sides. Also the Magid Mishneh (Hilchos Ma'achalos Asuros 6:11) says so in the name of the Rashba. Why does the Tur say that he holds that it is l'Chatchilah to salt only one side? This is wrong. However, the Rashba leans to say that for chickens or geese one need not salt them inside. Also R. Yerucham says so in his name. The Ran says like the Rashba, but requires salting a chicken also inside l'Chatchilah. Toras ha'Bayis ha'Aruch says so. He concludes that it is fine to put salt in chickens or geese, even though the salt does not cling above on the ribs when one lies them on the other side.

Taz (13): Isur v'Heter says that the same applies to any meat with a cavity. Therefore, one who salts the lungs must open the chambers first. A case occurred in which a lamb's head was salted only from the outside, and Rabbeinu Yehudah commanded not to salt it again, rather, to roast it. Surely, they had already cut open the head, and they should have salted also the inside, just like one must salt both sides of a piece. If it had not been cut open, it is permitted even if it was salted only from the outside, just like any other thick piece. One need not cut it (into thin slices) at the time of salting. The Beis Yosef (Siman 71) says that one must puncture the bone due to the brain and its membranes to allow the blood to leave (but one need not cut the head open).

Shulchan Aruch (ibid.): If one salted them only inside or outside, or if a piece was salted only on one side, it is permitted.

Rema: Some forbid even b'Di'eved. This is the custom, if there is not a need. This is only if it was already cooked. If it was not cooked yet, one may not cook it like this.

Gra (24): He holds that 'the same applies for a pot' is even Me'akev.

Beis Yosef (DH v'Zeh): Sefer ha'Terumah says that one must put much salt, so that one would not eat it. Too much salt harms the taste of meat. One must salt the meat from all sides. One must salt a chicken or lamb inside and outside. In Semag's text in Menachos, we conclude that one puts salt on one side, flips it over, salts the other side, and offers it. We do the same before roasting meat, i.e. but this is not enough to cook meat. Then, one must rub the salt until it is absorbed. The Mordechai says that some forbid a chicken that was salted only outside. A case occurred in which a lamb's head was salted only from the outside, and Rabbeinu Yehudah commanded not to salt it again, and not to cook it, rather, to roast it. The fire will draw out the blood. He wrote in the name of the Roke'ach that Rabbeinu Shmuel and Rabbeinu Shmearyahu are Machshir a bird that was salted only from the inside. There is no difference between the inside and outside. R. Avigdor says that if they salt it again from the outside, one may cook it in a pot. This implies that if it was salted only on one side, one may not cook it.

Beis Yosef (DH veha'Rashba): The Rashba rejected this. The Gemara in Menachos means that l'Chatchilah one must salt both sides before cooking. When possible, we salt all sides to remove the blood well. B'Di'eved, if one salted only the inside of a chicken or goose, or only one side of a piece, the Rashba permits. It seems that the Rosh agrees. We rule like this.

Taz (14): If it is a big loss, it is permitted if it was salted from one side, and all the more so if it was salted from both sides but the salt was not spread everywhere. Isur v'Heter is lenient b'Di'eved in the latter case, even though he is forbids the former case. Also Maharshal holds that the latter is more lenient. I permit the latter case even if it is not a big loss.

Shach (20): The Rema forbids also in the Reisha, when a place was left without salt. This is clear from Toras Chatas (Sof Din 7). Also the Maharshal says so in Yam Shel Shlomo; he retracted from what he wrote in his Isur v'Heter that this is a big stringency. However, the Bach (DH ul'Inyan) distinguishes like this (and permits when a place was left without salt). He has a good proof from Isur v'Heter (ha'Aruch 1:7, 7:7). The custom is not to be meticulous about this (if there was a place without salt).

R. Akiva Eiger: If fat was salted from one side, it is permitted (75:1).

Rema: Rather, if it is within 12 hours of salting, he salts the side that was not salted yet, and then he may cook it.

Shach (22): This is only if it was not rinsed yet. If it was rinsed after salting, the pores (to emit blood) closed, and salting afterwards does not help.

R. Akiva Eiger (DH Yachzor): Why does it help to salt the other side? The salt from the first side already lost its strength. It is like salting from one side again! We should salt again from both sides! Do not say that salting from one-side removes the blood from half the thickness. If so, we could cut the top half off, and it is permitted! The Rema connotes unlike this. Rather, the power of salt enters only a little, e.g. a finger. Now that we salt the other side, it similarly helps only for a finger. Blood remains in the middle! This requires investigation.

Rema: If it is after 12 hours, he roasts it, and the fire drsaws out the blood. The side that was salted does not absorb from the side that was not salted.

Shach (23 and Gra 26): Even if it would absorb, it would similarly emit what it absorbed (Chulin 93b, YD 73:12-14).