Gemara

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

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

Question (Abaye of Rava - Mishnah): If one cooked blood until it hardened and ate it, or melted Chelev and drank it, he is liable.

Answer: One is not liable for eating blood (Chulin or Kodesh) that congealed through cooking on a fire, for it cannot revert to blood. One is liable for eating blood that congealed in the sun, for it can revert to blood.

Question: The following shows that also blood that congealed in the sun is Nidcheh (loses the status of blood, and is Pasul for Zerikah)!

Question (Rav Mari): If one ate congealed blood, what is the law?

Answer (R. Yochanan): Once it congealed, it is Nidcheh (therefore, he is exempt).

Answer (Rava - Rav Chisda): If blood of an outer Chatas congealed, one who eats it is liable. It says "v'Lakach... v'Nasan." Since congealed blood can be taken and put (on the Keren), it is still considered blood.

If blood of an inner Chatas congealed, one who eats it is exempt. It says "v'Toval... v'Hizah" - since one cannot immerse (a finger) in or sprinkle congealed blood, it is not considered blood.

(Rava): One is liable even for congealed blood of an inner Chatas, since such blood of outer Chata'os is considered blood.

Inference (Rav Papa): One is liable for congealed blood of a donkey, since such blood of outer Chata'os is considered blood. (Had we not learned from outer Chata'os, we would have thought that one is exempt for blood of a donkey.)

(Rav Ashi): (For Kodshim,) one puts (much) salt on each side of the limb and offers it.

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

Chulin 109a (Mishnah): One tears the heart to remove the blood. If it was not torn, he does not transgress.

(Beraisa): One tears the heart to remove the blood. If he did not tear it, he tears it after cooking it, and it is permitted.

Rishonim

Rashi (109a DH ha'Lev): Kerisus 22a establishes our Mishnah to discuss a bird, in which the heart has less than a k'Zayis of blood. An animal's heart has more than a k'Zayis of blood, so if it was not torn, one who ate it after cooking would be Chayav Kares.

Rambam (Hilchos Ma'achalos Asuros 6:6): Whether one intends to roast the heart or cook it, he tears it and removes the blood, and then salts it. If he cooked it without tearing it, he tears it after cooking, and it is permitted. If he did not tear it and ate it, he is not Chayav Kares. This refers to a bird's heart, which has less than a k'Zayis of blood. One is Chayav Kares for an animal's heart, for it has a k'Zayis of blood for which one is Chayav Kares.

Magid Mishneh: Some say that one is Chayav Kares for blood of the heart only if he ate it raw, but one is exempt for cooked blood, like it says in Menachos. The Rambam did not clarify this.

Pri Megadim (Petichah l'Hilchos Melichah DH ha'Ikar ha'Echad): Perhaps the Magid Mishneh means that it is not clear whether the Rambam obligates Kares for cooked blood, but surely he obligates lashes. Alternatively, perhaps he exempts even from lashes (like the Lechem Mishneh explains below).

Lechem Mishneh: Maharal Ben Chaviv says that the Rambam connotes that one is liable for cooked blood. He obligates Kares for an animal's heart, without stipulating that this is before cooking. The Rambam never brings the teaching that one is exempt for cooked blood. This shows that he holds that the Halachah does not follow it.

Rambam (9:6): If one cooked meat in Chalav Mesah (milk found in a dead animal) or milk of a male animal, or cooked blood in milk, he is exempt (for cooking it), and he is not lashed for eating it due to meat and milk.

Beis Yosef (YD 87 DH Kosav ha'Rambam): The Rambam connotes that he is lashed for blood. This is unlike Menachos 21a! However, also Rashi says that one is liable for cooked blood. He must hold that the Halachah does not follow Menachos 21a. It seems that the Rambam agrees.

Bach (YD 87:4): The Beis Yosef asked why the Tur cited the Rambam but changed the order. I say that he shows that the Rambam holds that one who eats blood cooked in milk is exempt for meat and milk, but he is liable for blood. One could explain that the Rambam said 'he is not lashed for eating it due to meat and milk' (which implies that one who eats it is liable for something else) to refer only to meat cooked in Chalav Mesah, but one is totally exempt for eating blood cooked in milk, based on Menachos 21a. The Rambam's words 'he is not lashed for eating it (singular)' support this. They suggest that he discusses only one of the matters mentioned above. The Rashba exempts one who eats cooked blood.

Rosh (Chulin 8:33, also brought in Ran Chulin 41a DH ha'Hu in the name of R. Tam): R. Tam says that salting to remove blood is like cooking. A proof is from Menachos 21a. We prove that we do not salt blood, for this would disqualify it, just like cooking does. Kodshim are salted like we salt for cooking.

Tosfos (Chulin 111a DH Dam): The Isur of blood before it is cooked is mid'Oraisa.

Poskim

Shulchan Aruch (YD 69:10): If a Nochri works in a Yisrael's house and he put meat in a pot, and it is not known whether he rinsed it (to remove blood that comes out through salting), if the Nochri knows the practices of Yisrael, we rely on what he says, if a Yisrael was going in and out, or a minor with understanding.

Rema: It suffices if he says l'Fi Tumo (unaware of the consequences) that he rinsed it well, or a Yisrael, even a minor, was going in and out, for he fears to lie.

Beis Yosef (DH v'Chosav b'Sefer): Semak says that we rely on the Nochri, because the Chazakah is that he rinsed it well, for they are particular about cleanliness. Alternatively, he holds that the rule that a Nochri is believed l'Fi Tumo only for Edus Ishah (testimony that a man died to permit his wife to remarry) refers only to Torah Isurim. He is believed l'Fi Tumo for an Isur mid'Rabanan, like Terumas ha'Deshen (79) said. Here we discuss an Isur mid'Rabanan, since the meat was salted, and this is like cooking.

Darchei Moshe (19): The Beis Yosef did not need to say that salting is like cooking. In any case it is cooked in front of us! Therefore, if Meligah was done (a chicken was put in hot water), and we are unsure if it was in a Keli Rishon or a Keli Sheni, a Nochri is believed, for it is a Safek mid'Rabanan.

Hagahos Tur ha'Shalem (20, citing Minchas Yitzchak 1:13): The Beis Yosef teaches that we are lenient even if the meat was just put in the pot, and it did not cook yet.

Taz (24): A case occurred in which a woman cooked meat, and she was unsure if she salted it. The Maharshal permitted, for it is a Safek mid'Rabanan. Do not say that we should follow the Chazakah that it was not salted. If we did, a Nochri l'Fi Tumo would not override the Chazakah (that it was not rinsed). I found in the name of Hagahos Sha'arei Dura that we are lenient about a Safek whether or not it was rinsed, because it is a Safek mid'Rabanan. Even though the Beis Yosef wrote that Rashi and the Rambam holds that the Torah forbids cooked blood, all the Acharonim were not concerned for their opinion, since the Gemara explicitly says that it is mid'Rabanan. Also, we can say that she surely did like usual, like we say that one who was unsure if he just said "u'Chsavtram" of the first or second Parshah of Keri'as Shma, and he began "Le'ma'an Yirbu...", he need not go back. Surely he (was in the second Parshah, and) followed his usual practice. A majority (she usually salts before coking) is stronger than a Chazakah, and overrides it.

Shach (42): The Mechaber did not mention l'Fi Tumo, for he rules that we do not rely on a Nochri l'Fi Tumo even for an Isur mid'Rabanan. Rather, we rely on the fact that the Nochri fears to lie.

Bach (72:5): If the heart of a bird was not torn and it was cooked stuffed with eggs, since the blood is less than one part in 60 of the bird, it is permitted. Do not say that the eggs became forbidden like Neveilah, and forbid the entire bird. When there are other Sefekos, we are not stringent about cooked blood, because there are opinions that it is only an Isur mid'Rabanan.

Shulchan Aruch (87:6): If one cooked blood in milk, he is exempt, and he is not lashed for eating it due to meat and milk.

Shach (15): The Mechaber cited the Rambam, who holds that one transgresses for eating cooked blood, but we hold that it is only mid'Rabanan.

Pri Megadim (Petichah l'Hilchos Melichah DH ha'Ikar ha'Echad): The Ro'oh holds that cooked blood is only mid'Rabanan, like Tosfos, but we are not lenient about all Sefekos, since it is very close to a Torah Isur. Also the Rashba and the Acharonim say that it is mid'Rabanan, but one may be lenient about a Safek only where this was taught, or if there are other reasons to be lenient.

Pri Megadim (ibid., DH v'Hinei l'Fi): Blood loses its status if it is salted so much that it cannot be eaten, but not through light salting.

Mishbetzos Zahav (on Taz 69:35, explaining Nekudas ha'Kesef): Even though blood in meat is permitted (before it leaves the meat), one may not cook it, for one may not turn a Torah Isur (the blood, after it will leave) into a mid'Rabanan Isur.

Nekudas ha'Kesef (on Taz 90:2): The Taz asked why the Rema is more lenient about udder than cooked blood. Both of them are forbidden mid'Rabanan! I answer that blood was forbidden mid'Oraisa after it separated, before it was cooked. Udder was never forbidden mid'Oraisa.