A. Hardboiled eggs cooked with meat:
If an egg was cooked together with meat or poultry [i.e. Fleishig stew or Chulent] then the egg becomes Fleishig and it is forbidden to eat the egg with dairy. Furthermore, one must wait 6 hours after eating the egg prior to eating dairy. This applies even if the egg was cooked within its shell.
B. Hardboiled eggs cooked in meat pot with only Pareve:
Not Ben Yomo: If an egg was cooked in a [clean] meat pot that was not Ben Yom [i.e. past 24 hours of cooking or soaking meat], then the egg remains Pareve and may even initially be eaten together with dairy products. [However, some Poskim rule that it is forbidden to initially cook Pareve food in a non-Ben Yomo meat pot with intent to eat the food with milk products, or vice versa. Other, Poskim, however, rule that it is permitted to do so even initially with intent to eat with the opposite food. Practically, Sephardim may be lenient even initially, and Ashkenazim may be lenient in a time of need, such as if there is no other pot available. According to all, if one already cooked the Pareve food in a non-Ben Yomo meat pot with intent to eat with milk, he may eat it with milk. ]
Ben Yomo: If an egg was cooked in a [clean] meat pot that was Ben Yom [i.e. within 24 hours of cooking or soaking meat], then some Poskim rule that the egg remains Pareve and is permitted to be eaten with milk products, even if the pot was Ben Yom, and so is the accustomed ruling for Sephardim. [This applies even if the egg was peeled from its shell prior to being cooked, so long as the pot was not dirty.] Other Poskim, however, rule that the egg is forbidden to be eaten with milk products [although one is not required to wait six hours after eating it, prior to eating dairy] and so is the accustomed ruling for Ashkenazim. However, Bedieved, if one already cooked it with milk products, the mixture is permitted [even if the food does not contain 60x].
C. Fleishig born eggs-Eggs found in a chicken after slaughtering:
While a chicken is alive, it is only permitted to eat eggs that are naturally laid by the chicken after the gestation period is complete. If, however, the egg was removed or knocked out of the live chicken, and was not naturally laid, it is forbidden to eat the egg due to Eiver Min Hachaiy. However, if the egg is found in a slaughtered chicken, then even if the egg is still attached to the sinews of the chicken, the egg remains Kosher. Nonetheless, the Talmud and Poskim state that in certain circumstances, the egg may be considered meaty, and hence forbidden to be eaten with milk. This is dependent on the stage of development that the egg was found in, as will now be explained.
Contains yolk and white: An egg which is found in a slaughtered chicken is permitted to be eaten together with milk if it is fully developed with both a white and yolk. This applies even if the egg is still attached to the sinews. Nonetheless, the custom of the women is to salt such eggs even if it contains a thick shell [and is detached from the sinews], and not to eat it with milk. The above custom is only Lechatchila, however, Bedieved if the egg became mixed with dairy, everything remains Kosher. [Furthermore, communities which do not have the above custom are not to suspect for it at all. The above custom to be stringent not to eat the egg with dairy only applies to eggs found in the chicken after slaughter, and not towards eggs that are naturally laid, even if they have a soft shell and were prematurely laid.]
Contains only yolk: If the egg has not yet fully developed and contains only a yolk without a white, then it is forbidden to cook it or eat it with milk [even if it is not attached to the sinews, and certainly if it is still attached]. Such eggs must be salted for blood prior to being eaten, and may even initially be salted together with meat. However, even in such a case [i.e. only has a yolk and was attached to the sinews], it is permitted to eat milk products after eating the egg. [If these eggs were cooked with milk, some Poskim rule that in a case of great loss one may be lenient to eat the mixture even if it does not contain 60x the egg. This applies even if the egg was still attached to its sinews and only had a yolk, so long as its shell was hard. Other Poskim, however, rule the mixture is forbidden unless it has 60x the egg.]
 Rama 89:3; Beis Yosef O.C. 173; Peri Chadash 89:18; Kneses Hagedola 89:42; Lechem Hapanim 89:23; Birkeiy Yosef 89:30; Zivcheiy Tzedek 89:31; Kaf Hachaim 89:50, 52, 53, 55, 58
Other opinions: Some Poskim rule that one who ate meat gravy, but not actual meat, is not required to wait 6 hours prior to eating dairy. [Michaber 89:2] Practically, the final ruling and custom is unlike this opinion.
 Michaber 95:2
The reason: The reason for this is because egg shells contain pores which allows the meat taste to penetrate, as can be seen from the fact an egg changes colors when cooked in dye. [Beis Yosef 95 in name of Rashba; Taz 95:2] Alternatively, egg shells do not contain pores but nonetheless absorb being that their shell is thin and allows meat taste to penetrate and leave. [Taz 95:2 although in conclusion he does not disagree with the Rashba’s holy words.] See however, Michaber 86:5 that regarding Treif eggs we hold that the taste does not penetrate through the shell and prohibit other food.
 Rama 95:2
Other opinions: Some Poskim rule that initially one may not eat Pareve foods cooked in a non-Ben Yomo meat vessel together with milk. [Rashal Issur Viheter Shelo on Shaareiy Dura; Yam Shel Shlomo Kol Habasar 63, brought in Taz 95:4]
 Shach 95:2 Chavas Daas 95:3; P”M 95 S.D. 2; Zivcheiy Tzedek 95:16; Kaf Hachaim 95:18
 The reason: The reason for this is because the taste of the pot is considered spoiled and is Nat Bar Nat and thus we are lenient even initially.
 Devar Moshe Y.D. 9; Chochmas Adam 48:2
 Beis David Y.D. 42; Zivcheiy Tzedek 95:4; Kaf Hachaim 95:3
 The reason: As in such a case we have two reasons for leniency; 1) The pot is not Ben Yomo 2) The meat taste is Nat Bar Nat. [Kaf Hachaim ibid]
 Zivcheiy Tzedek ibid; Kaf Hachaim ibid; Hakashrus 1:36
 Chochmas Adam ibid; Koveitz Mibeis Levi 4:179-66; Hakashrus 1:36; 10:95; See Rama 89:3 and Shach there
 Peri Chadash 95:1; Lechem Hapanim 95:3; Kreisi 95:1; Kehilas Yehuda 95:1; Zivcheiy Tzedek 95:5; Kaf Hachaim 95:5
 Shach 95:2 Chavas Daas 95:3; P”M 95 S.D. 2; Zivcheiy Tzedek 95:16; Kaf Hachaim 95:18
 Michaber 95:1-2; ; Beis Yosef 95 in name of Rashba; Rambam Machalos Assuros 9:23; Rashi, brought in Tur 95:1 [unlike understanding of Rivan]; Rabbeinu Tam; Riy Hazakein; Sefer Hateruma 61, and Rosh Chulin Kol Habasar 29, brought in Tur ibid regarding cooking [as opposed to roasting]
According to the Michaber, may one initially cook Pareve foods in a meat vessel in order to eat with Milk? Even according to the Michaber, it is initially forbidden to cook Pareve food in a Ben Yomo meat pot with intention to eat that Pareve food with dairy products. [Admur 494:16; Shach 95:3; Taz 95:4; Rabbeinu Yerucham 15:28, brought [and negated] in Beis Yosef 95:1 in Bedek Habayis; Semak 213 and 198, brought in Beis Yosef ibid; Peri Chadash 95:1; Minchas Kohen 1:12; Lechem Hapanim 95:3; Beis Lechem Yehuda 95:3; Kreisi 95:1; Erech Hashulchan 95:5; Kehilas Yehuda 95:1; Zivcheiy Tzedek 95:2; Ben Ish Chaiy Korach 13; Kaf Hachaim 95:1 and 21 that the Michaber ibid retracted from his ruling in the Beis Yosef which was written before his Shulchan Aruch [see Yad Melachi 15; Chida in Shem Hagedolim Sefarim 75], and therefore the ruling in Michaber ibid is written in the form of Bedieved; Rav Shalom Mashash in Mizrach Shemesh 95 and Shemesh Umagen 1:8; 2:42] Thus, one may not heat water in a Ben Yomo meat pot for the sake of kneading dough, as one often eats bread with dairy. [Devar Moshe Y.D. 9; Shulchan Gavoa 1; Zivcheiy Tzedek 95:3; Kaf Hachaim 95:2] The same applies vice versa. However, some Poskim rule that according to the Michaber it is permitted to even initially cook Pareve foods in Ben Yomo meat pot with intent to eat with dairy. [Beis Yosef 95:1 in Bedek Habayis, printed and his commentary on the Tur, writes that one may even initially cook in the Ben Yomo pot with intent to eat with the opposite food [However, the Poskim ibid say the Beis Yosef retracted this ruling in his Shulchan Aruch and rules that it is only allowed Bedieved.]; Maharah Even Tava in Shut Tashbatz Chut Hameshulash, Hatur Hasheleshi 33; Beis David 42; Pnei David Papau 2; Beis Yehuda 2:92; Yabia Omer 4:4; 94; Rav Yitzchak Yosef; See Hakashrus 1:35; 2:19] Even according to the first approach, if one already cooked the Pareve food in a Ben Yomo meat pot with intent to eat with dairy, he may go ahead and eat it with dairy. [Peri Chadash 95:1; Lechem Hapanim 95:3; Kreisi 95:1; Kehilas Yehuda 95:1; Zivcheiy Tzedek 95:5; Kaf Hachaim 95:5 unlike Minchas Kohen 1:12]
 Kaf Hachaim 95:21
The reason and explanation: As this is a classic case of Nat Bar Nat Dihetera, similar to the fish case discussed in 95:1. [Beis Yosef ibid] The meat taste that the Pareve food contains has traveled from the meat to the pot and then from the pot to the Pareve food. This is called Nat Bar Nat Dihetera. The reason that this meat taste is not considered problematic with dairy is because the meat taste which the Pareve food absorbed from the Ben Yomo pot is so indirect and diluted that it does not have sufficient intensity to merge with milk and cause a fusion of Basar Bechalav. [Taz 95:1; Kneses Hagedola 95:24 in name of many Poskim; Peri Chadash 95:3; Lechem Hapanim 95:2; Chochmas Adam 48:17; Zivcheiy Tzedek 95:15; Kaf Hachaim 95:8]
 Shach 95:2 Chavas Daas 95:3; P”M 95 S.D. 2; Zivcheiy Tzedek 95:16; Kaf Hachaim 95:18
 Opinion in Rama 95:2; Rivan in name of Rashi; Issur Viheter Aruch Klal 34 [brought in Darkei Moshe 95:1]; Mordechai; Or Zarua; Rabbeinu Yerucham 15:28, brought in Beis Yosef [Bedek Habayis 95:1]; Shach 95:3; Peri Chadash 95:4; Lechem Hapanim 95:4; Beis Lechem Yehuda 95:3; Kreisi 95:4
 The reason: The reason for why the Rama is stringent is because the Rama rules Nat Bar Nat Dihetera is initially forbidden.
 Rama 89:3; Darkei Moshe 89:6; Beis Yosef O.C. 173; Shach 89:19
 Rama ibid; Semak; Aruch; Taz 95:4 that one who is lenient like the Rama has not lost out; Admur 494:16 [that we only suspect for Nat Bar Nat Lechatchilah]; Peri Chadash 95:5; Lechem Hapanim 95:6
Other opinions: Some Poskim rule that Pareve food which was roasted in a Ben Yomo meat pot, is forbidden to be eaten with milk products and even Bedieved the mixture is forbidden unless there is 60x versus in the milk versus the food. [Rashal Issur Viheter Shelo on Shaareiy Dura; Yam Shel Shlomo Kol Habasar 63, brought in Shach 95:4; Beis Lechem Yehuda 95:4 in name of Poskim; Kaf Hachaim 95:22 concludes that one who is stringent like the Rashal in a case that does not involve a great loss, is blessed.] The above Poskim are only stringent regarding a roasted food. However, a food that is cooked in liquid inside of a meat pot, or a food that is roasted in a meat pot that is Ben Yomo from meat that was cooked in liquid, is permitted Bedieved if it became mixed with dairy. [Chavas Daas 95:5; Pischeiy Teshuvah 95:4; Kaf Hachaim 95:2]
 See Michaber 87:5; Tur 87:5; Beitza 6b-7a
Background: The Gemara in Beitza ibid states that a developed egg which is found in a chicken may be eaten together with dairy. This implies that an undeveloped egg is considered like meat and may not be eaten together with dairy. The Rishonim and Poskim debate as to the definition of an undeveloped egg, with some holding that even if only the yellow part has been developed the egg is considered pareve, and others holding that so long as the white has not yet developed then it is considered meaty, and others holding that so long as it is still attached to the sinews it is considered like meat. Below we will clarify the final ruling in the different opinions in the Poskim as well as the Jewish custom.
 Michaber Y.D. 86:4; Shach 87:9; Taz 87:6; Kaf Hachaim 87:39; See coming footnotes.
 The egg of a Neveila bird which was killed or naturally died: Eggs found in a dead Neveila chicken are Rabbinically forbidden in consumption. [Michaber 86:3; Shach 86:8]
 Michaber 87:5
 Michaber ibid; Tur 87:5 in name of Rashba; Rashba in Toras Habayis Bayis Gimel Shaar Daled 84b; Rabbeinu Yerucham Nesiv 15:22; Ran Beitza 3b
 If the shell is soft: The Shach 87:10 rules that even if the egg was fully developed and detached from the sinews if the shell is soft, it is initially forbidden to eat the egg with milk. However, Bedieved if it was already cooked with milk it is permitted to eat the mixture in a case of great loss. Although if it was attached to its sinews [and has a soft shell even if fully developed] then even Bedieved it is forbidden. [Shach ibid] Other Poskim, however, argue and rule that in all cases that the egg contains a white and yoke, it is permitted to eat with dairy even if it has a soft shell and is attached to its sinews. [Peri Chadash 87:9]
Small eggs: Small eggs that only have the yolk developed, even if they are not attached to the sinews, are considered like actual meat, although according to the lenient opinion of Rashi, even if only the yolk has developed and the egg is attached one can be lenient Bedieved if it was cooked with milk and there is a great loss.
 Michaber ibid; All Poskim and Rishonim ibid
Why is the egg not considered meaty due to Eiver Min Hachaiy? If an egg was knocked out from a live bird then if it is attached to its sinews it is always forbidden due to Eiver Min Hachaiy, no matter what its stage of development. [Michaber 86:4; Shach 87:9; Taz 87:6] This does not contradict the ruling here that the egg is not considered meat, as Eiver Min Hachaiy applies even by non-meaty parts of the animal. This can be seen from the allowance of milk, that if not for the Torah’s explicit allowance it too would be forbidden due to Eiver Min Hachaiy. Hence although an egg that is attached to its sinews is forbidden due to Eiver Min Hachaiy when it is knocked out of a live chicken, nevertheless this does not mean it is considered meat, and in truth the egg is considered Pareve if it was fully developed. [Shach 87:9] Alternatively it can be explained that only regarding Eiver Min Hachaiy which is Biblical do we view the egg as meat, however regarding the prohibition of meat and milk which is only Rabbinical with chicken, we are not stringent regarding a chicken egg to consider it meat. Or perhaps since each food is permitted on its own we do not consider their mixture to make a new entity of Issur of Basar Bechalav. Nevertheless, the above explanations are unnecessary, as in truth, the egg is not considered meat at all. [Shach ibid]
Opinion of Rashal: The Rashal [brought in Taz 87:6] however rules that all eggs which are attached to their sinews are considered meat for all matters. His reasoning is because we see from the law of Eiver Min Hachaiy, that when an egg gets pushed out from a chicken when it was still attached to its sinews that it is Treif. One must say, says the Rashal, that the reason for this is because the egg is considered meat so long as it is still attached. Hence, so too here the egg is considered meat even when fully developed if it is still attached to the sinews.
 It is initially to be salted by itself, without meat. [Rama 75:1; Kaf Hachaim 87:40]
 Rama 75:1; Taz 87:6; Shach 87:10; Toras Chatas Klal 70:1 in name of Mahariy; Darkei Moshe 87:3; Rashal Kol Habasar 2; Bach 87; Beis Hillel 87:4; Lechem Hapanim 87:10; Beis Lechem Yehuda 87:7; Chochmas Adam 40:5; Beis Yitzchak 87:5; Kaf Hachaim 87:37
Background of the custom of women to forbid all eggs: The Mahariy [brought in Rashal and Shach 87:10] rules that the women are accustomed to being stringent to avoid eating eggs found in slaughtered chickens even if the shell is hard [and it is detached from the sinews]. The Rashal concludes that Bedieved one is not to be stringent if the shell has completed, even if it is soft. [Taz 87:6] The Shach [87:10] likewise brings this custom of women and concludes it is a mere stringency and in an area where this custom was not accepted they do not need to follow it [even if the egg is attached to the sinews] as when the outer shell is hard, it is permitted even initially to eat it with milk.
 Rama ibid; Taz ibid; Shach ibid; Toras Chatas ibid; Beis Hillel ibid; Chochmas Adam ibid; Beis Yitzchak ibid; Kaf Hachaim 87:38
 Shach ibid; Lechem Hapanim ibid; Kaf Hachaim 87:38
 Sheilas Yaavetz 1:102; Pischeiy Teshuvah 87:12
 Michaber ibid; Tur 87; Rashba in Toras Habayis Bayis Gimel Shaar Daled 84b; Rabbeinu Yerucham Nesiv 15:22; Ran Beitza 3b
Other opinions: Some Poskim rule that even if the egg has only developed the yolk and not the white, and is found attached to the sinews, it is considered Pareve and may be eaten with dairy. [Tur 87 in name of Rashi; Rashi Beitza 6b; Tosafus Beitza 7a; Rosh 1:8; Rabbeinu Yerucham Nesiv 15:28; Brought in Shach 87:12]
 Michaber writes cook, Shach [87:11] writes he means “eat” as even chicken itself the Michaber rules may be cooked with milk. [However, just as cooking chicken with milk is forbidden due to Maaras Ayin, so too the same would apply to this form of egg.]
 Shach 87:10; Peri Chadash 87:9
 Rama 75:1
 Shach 87:12; Peri Chadash 87:10; Peri Tora 87:13; Lechem Hapanim 87:11; Beis Lechem Yehuda 87:9
 Michaber ibid; Orchos Chaim Issuei Machalos 72 in name of Rav Yonason of Lunil
Other opinions: Some Poskim rule one is to be stringent and not eat dairy within six hours of eating such eggs, just as is followed regarding poultry. [Peri Chadash 87:10; Peri Tora 87:13; Lechem Hapanim 87:11; Beis Lechem Yehuda 87:9; Zivcheiy Tzedek 87:32; Kaf Hachaim 87:42]
 Shach 87:10; Beir Heiytiv 87:8; Based on ruling of: Tur 87 in name of Rashi; Rashi Beitza 6b; Tosafus Beitza 7a; Rosh 1:8; Rabbeinu Yerucham Nesiv 15:28; Brought in Shach 87:12
 Peri Chadash 87:9; Zivcheiy Tzedek 87:31; Kaf Hachaim 87:41