Rabbi Michael Broyde
Associate Professor of Law, Emory Law School; Rabbi, Young Israel of Toco Hills; Dayan, Beth Din of America
Journal of Halacha & Contemporary Society - XL; Fall 2000 - Sukkot 5761

Key words: checking eggs for blood spots, range eggs, organic eggs,

Farming questions are among the most interesting in modern Jewish law in America because we have grown farther and farther away from the reality of the farm, and thus we find keeping a firm grasp on the reality to be exceedingly difficult. Such is clearly true in the case of egg production, which has changed considerably in the last twenty years, and changed dramatically in the last century.1

A. Chicken Farms
Until relatively recently, chicken eggs were laid on a farm that was an integrated farm; besides chickens, there were other animals on the farm, and birds (both kosher and not) were part of the farm environment. Three distinctly different activities would occur on a farm with the chickens. Chickens would lay eggs which the farmer intended to sell as table eggs; chickens would lay eggs that would be hatched to produce chicks; chickens would be raised to be slaughtered for their meat. The same chickens frequently would be used for all three activities, with short term economic needs determining whether any particular egg would be sold as a table egg or hatched, and when any given chicken might be slaughtered.

About a century ago chicken farms became common; on a chicken farm only chickens were raised, and all other animals were excluded. In the last twenty years this trend of farm specialization has continued even more dramatically. In America since 1970, separate and distinct chicken farms exist to produce only table eggs.2 No chickens are raised on this farm for slaughter and no chicks are hatched. Thus unlike the chicken farms of even fifty years ago, these hen coops have absolutely no roosters on the farm at all, and sometimes will have as many as one million hens producing eggs, seven days a week, throughout the year. The feed given these hens and the lighting conditions are uniquely suited to egg production only.

B. Blood Spots in Eggs
In talmudic times, blood spots occurred in eggs because of two distinctly different reasons. The first was that the egg had been fertilized and a chicken embryo was in formation. The second was that a tissue irregularity in the hen caused a small amount of blood to be deposited in the egg. In America in modern times, since there are no roosters in the egg-laying coop, only the latter occurs, and incidence of that is relatively low (markedly less than 1% of all eggs will have a blood spot).

In addition, United States government regulations require that Grade A and Grade AA table eggs be checked for blood spots in a process commonly referred to as candling (although it is now done with an infrared light) before eggs can be sold to the consumer as grade A or AA. Thus the incidence of blood spotting in grade A or AA table eggs is very, very small in the United States (perhaps as low as one in 1,000). Eggs with blood spots (or other deformities) are marketed as grade B eggs, which are then sold to commercial manufacturing plants to be used as ingredient in manufactured items. The incidence of blood spotting in grade B eggs varies based on a number of factors, and is not regulated by the government. Neither grade A nor grade AA eggs are ever produced in a chicken coop with roosters present, and it is improper to take an egg intended for hatching and sell it as a table egg; it is also very difficult to do, as chicken hatching farms are not licensed to sell eggs commercially to the public.3 Such eggs would never be found in a supermarket as a grade A or AA egg, although if one buys eggs from a roadside stand or a farmers' market, such eggs might be included in the eggs sold.

Blood Spots and the Classical Halacha
A. Blood Spots in Eggs that Might be Fertilized
The Talmud addresses the question of blood spots in eggs a number of different places, and the Rishonim disagree on the exact contours of the halacha.4 Most Rishonim adopt the view that any blood in an egg that is present because of the fertilization process, and is the result or the by-product of such, makes it biblically prohibited to eat the whole egg.5 These same Rishonim generally agree that all other blood in an egg is rabbinically prohibited to eat, although some Rishonim assert that there are places in an egg where blood can be such that it is permitted to eat the egg and the blood spot too.6 A small group of Rishonim assert that it is never a biblical violation to eat blood in an egg, and that Torah law is violated only if one eats an egg after the embryo actually begins to form.7

There is an intricate literature about how to determine what type of blood spot is a biblical prohibition and what is a rabbinic prohibition.8 This distinction is of significant halachic importance as, in cases where the blood spot resulted from fertilization, the whole egg must be discarded, whereas when the blood spot is merely a result of a tissue formation accident in the hen, the blood spot must be removed, but the rest of the egg may be eaten.9 There are no less than five views found in the Rishonim and among the commentaries on the Shulchan Aruch as to when a blood spot causes the whole egg to become unkosher, or when just the blood spot needs to be removed or when just the blood spot plus the surrounding area need to be discarded.10 These opinions focus on where the spot is located - in the yolk, on the yolk, in both the yolk and the albumin, in just the albumin, or floating clear, and there is no absolute consensus as to what the halacha is.11

Because of the complexity of these rules, and from the fact that an error can easily lead to one's eating an egg which is prohibited according to Torah law, Rabbi Moshe Isserless (Ramo) states:

From this derives the common custom in our community to prohibit all eggs with blood spots, and not to distinguish between blood spots in the yolk or in the albumin12 ...and this has always been the practice.13

However, Ramo notes that this custom is limited to cases where the egg has not yet been added to a food mixture. Once the egg is added to a mixture, there are many more grounds to be lenient, and Ramo permits the food stuff to be used if an egg with a blood spot is mixed into a food product.14

B. Blood Spots from Coops with only Hens and the Halacha
All of the above discussion was applicable in a case where the blood spot in an egg might derive from a fertilized egg, and there is a possibility of violating a Torah prohibition by eating such an egg. However, Shulchan Aruch states clearly that "eggs from a coop where there are no roosters may be eaten, even if the hen sat on the eggs for may days, so long as one removes the blood spot."15 Indeed, some Rishonim are of the view that when one has an egg with a blood spot from a hen that has been separated from a rooster, even the blood spot may be eaten, although the normative halacha appears to reject this view.16

Since table eggs in the United States never have blood spots that are the result of the fertilization process, there is a consensus among the halachic authorities of our day that there is no obligation or even custom to throw out the whole egg when one sees a blood spot. Rabbi Ovadia Yosef notes that the custom is to simply remove the blood spot and eat the egg;17 Rabbi Moshe Feinstein agrees that one may simply remove the blood spot and eat the whole egg,18 as does Dayan Yakov Weiss.19 In cases where the blood spot from such an egg is mixed in with other food products, the food is kosher, and the utensils do not need to be made kosher again.20

Not withstanding the halachic possibility of removing only the blood spot, most people simply find it too taxing or messy to actually remove just the blood spot when they see one, and thus simply throw out the whole egg rather than engage in the effort needed to remove a small portion of an egg and keep the rest of the egg.21

Checking Eggs for Blood Spots in America
Even in pre-modern farms, halacha did not require that one check eggs for blood spots before eating them. Shulchan Aruch states that one does not even have to check eggs generally and the "one can eat toasted eggs even though one cannot check them."22 However, Ramo adds that:
One does not have to check eggs to see if they have blood spot, as one relies on the fact that most eggs do not; nonetheless, people have the custom to be strict and check the eggs for blood spots when cooking during the day.23
The reason for this custom is obvious. First, if one does not check an egg for a blood spot, and one sees the blood spot during the cooking process or even later, one might have to discard all the food. Second, one might miss blood spot and eat food which is prohibited to eat.24

The crucial question is whether the halachic custom to check eggs must still be observed or whether it is possible to be lenient on this matter and simply not check any eggs generally. The answer to this question is not simple. It might be that one does not have to check eggs for blood spots, but when one is seen, it is still required to remove it according to Jewish law, and thus, it is prudent to check the eggs before placing them in a situation where it is difficult to remove the blood spot.

Thus it is possible to conclude that Jewish law does not require that one check eggs for blood spots prior to their use if one purchases grade A or AA eggs from a supermarket in America, although there is a minhag to check eggs, and one who checks for such eggs is in the category of Hamachmir tavo alav bracha, (pious conduct for which one is blessed for being strict). No less than six different reasons can be provided to justify the practice of not checking eggs prior to using them:

1. The United States Department of Agriculture already requires that all eggs be checked for blood spots before they can be sold in a supermarket as grade A or AA eggs.25 There was never a custom to check twice for blood spots.
2. There are virtually never blood spots found in eggs sold in supermarkets in America that are a result of fertilization; thus no biblical violation is ever present even if there is a blood spot in the egg. The custom to check all eggs was limited to a society where not checking might lead to a Torah violation.
3. There never was a custom to check for blood spots when all eggs derive from hens raised alone, in which case some authorities rule that even the blood spot itself can be eaten.
4. The incidence of blood spots in Grade A or AA eggs sold in the supermarket is less than one in a thousand, and generally one does not have to check for very infrequent rabbinic prohibitions.26
5. Halacha never required that one check for blood spots; it was a custom, and the custom itself did not apply when it was difficult to check, such as at night. Nowadays, given the way we cook, checking is more difficult in a variety of settings.27
6. If there is a blood spot in the egg, one will generally see it even after the egg has been opened, and one can remove the blood spot then.

This approach is fully consistent with other cases found in halacha where there once was a custom to check and changes in reality have diminished or even removed the obligation to check.28 Indeed, it is possible that future changes in agricultural reality will require a change in the practices found in kosher homes on other matters (or even this matter).

The common practice in commercial settings, where large numbers of eggs are used and checking is expensive (but not impossible) is not to have a Jew check even grade B eggs, which have a markedly higher incident of blood spotting than grade A or AA eggs.29 This is even more so true given the fact that once a blood-spotted egg derived from a chicken coop with only hens is actually mixed with other foodstuff, all the food, as well as the utensils, are permitted to be used.30 Such nullification is commonly relied on in the commercial setting, as it would be extremely expensive to check every egg.

However, even though halacha does not require that one check every grad A or AA egg purchased in a supermarket prior to using it, there might be prudent reasons why a person might choose to do so, and this explains the common practice of checking eggs found in many Ashkenazi homes.31 Most significantly, if one sees a blood spot, one must remove it, and it is easier to remove a blood spot prior to adding the egg to food than afterwards. So, too, a person who purchases brown eggs, free range eggs, organic eggs, or eggs sold at a farmers' market, has to check those eggs, and thus it might simply be easier to check all eggs than to monitor what type of egg one is using at any given time. Finally, one who frequently travels abroad, where the economic conditions relating to egg farming might be different, will certainly have to check eggs before using them, and might find it easier to simply check all eggs.


1. For more on egg technology, see William J. Stadelman and Owen J. Cotterill, editors Egg Science and Technology (Fourth edition, 1995, Food Products Press, New York).
2. In a different era there was a considerable amount of concern that an egg might come from a non-kosher bird, and be used in liquid form as an addition to other foods; see Shulchan Aruch, Yoreh Deah 86:10 and the comments of Shach, Yoreh Deah 86:30. However, since in the United States there are absolutely no non-kosher eggs used in the manufacturing process, very few non-kosher eggs are sold generally, and there is intense governmental inspection designed to prevent a company from using anything other then chicken eggs, the actual species of egg used is no longer a halachic concern in the United States. Less than one in every 100,000 eggs sold are other than chicken eggs (and most of those are duck or turkey eggs, which are also kosher).
3. Free range and organic eggs are subject to much less regulation, but must be sold with a notation that they are such. Free range eggs might actually be fertilized. Such eggs constitute less than one tenth of one percent, and perhaps as little as one thousandths of one percent of the 67.3 billion egg market in the United States.
4. See Chulin 64b.
5. Tur and Shulchan Aruch Yoreh Deah 66:1-2.
6. Tur in the name of the Ri, and Beit Yosef in the name of Rashi on Yoreh Deah 66:2.
7. Beit Yosef Yoreh Deah 66:1.
8. Tur and Shulchan Aruch Yoreh Deah 66:2-5.
9. Shulchan Aruch Yoreh Deah 66:2, and there are some blood spots that some Rishonim rule can even be eaten.
10. See Shulchan Aruch Yoreh Deah 66:1-4, with particular focus on the lengthy dispute found between Shach and Taz, as well as the listing of opinions found in Tur 66:2. In addition, it is worth noting that while Beit Yosef (YD 66:2) does cite a small number of Rishonim who are of the view that eating the blood in an egg is a biblical violation related to sheretz, Tur, Shulchan Aruch, Aruch Hashulchan and every other modern decisor rejects this view.
11. See sources cited in note 10.
12. Ramo Yoreh Deah 66:2.
13. See Aruch Hashulchan 66:15-16.
14. Shulchan Aruch Yoreh Deah 66:4. A second issue that used to be relevant to eggs was the possibility that the eggs sold were harvested from slaughtered chickens (called "ova eggs" by the USDA); such eggs are not kosher if taken from a chicken slaughtered other than in a kosher manner. There was a time when the USDA appended a "kosher statement" to eggs noting that no eggs were ova eggs, but change in the economics of egg farming has reduced the number of ova eggs to nearly none, making this issue non longer relevant. For more on the halachic issues raised by these eggs, see Yabia Omer Yoreh Deah 5:6.
15. Shulchan Aruch Yoreh Deah 66:7.
16. Rashi cited in Beit Yosef Yoreh Deah 66:7. This view is elaborated on at some length in the newly published Aruch MeShach on Yoreh Deah 66 found in the back of the Machon Yerushalayim Tur on Yoreh Deah 66. In light of the Aruch MeShach, one is inclined to interpret Shach (Yoreh Deah 66:14) which quotes Rashi's view as permitting not only the egg to be eaten, but even the blood spot itself. Indeed, Shach in Aruch MeShach Yoreh Deah 66 (page 5, s.v. vehaTur) seems to accept just this argument, and notes that there is conceptual difference between prohibiting eating blood-spotted eggs from eggs raised with roosters and blood-spotted eggs from hens alone. By this argument, blood spots in hens raised with roosters are rabbinically prohibited, but blood spots in hens raised without roosters are either not prohibited or only prohibited because of marit ayin, which is inapplicable when all eggs are from coops with no roosters; see Ran cited in Aruch MeShach; but see Biur Hagra Yoreh Deah 66:12.
17. Yabia Omer Yoreh Deah 3:2
18. Iggerot Moshe Yoreh Deah 1:36. This responsum was written in 1957. Writing in 1957, Rabbi Feinstein, states that he spoke to a farmer who told him that sometimes hatching eggs are actually mixed with table eggs by the farmer, and thus Rabbi Feinstein concludes that "it is proper to be strict and discard the whole egg, although this is not required according to Jewish law." The reality has changed considerably since the writing of this responsum, making it even less likely that such mixtures occur. It is no longer a statistically recordable possibility that a fertilized egg will be sold as a grade A or AA table egg. See also Iggerot Moshe Orach Chaim 3:61.
19. Minchat Yitzchak 1:106 and 4:56(3). The lone contrary voice seems to be Rabbi Avraham David Horowitz, Kinyan Torah 2:7, although it appears to me that his view is grounded in facts that are categorically not correct in America, as there are absolutely no roosters present in egg producing farms, a reality that perhaps was not present when Kinyan Torah 2:7 was written.
20. Iggerot Moshe 1:36; see also Tiferet leMoshe cited in Pitchai Teshuva Yoreh Deah 66:2 who discusses this issue also.
21. Rabbi Yosef observes that in Israel the custom is to actually discard the blood spot and eat the eggs, as discarding an egg was considered a matter of some loss. A single egg in America now costs less than a dime, and thus is a negligible loss.
22. Shulchan Aruch Yoreh Deah 66:8.
23. Ramo Shulchan Aruch Yoreh Deah 66:8. This is argued with by Beit Yosef Yoreh Deah 66:8 as well as by Maharil, Issur Veheter, Sharai Durah dinai betzim.
24. Kitzur Shulchan Aruch states it simply: "Blood in eggs is prohibited to eat and sometimes even the whole egg may not be eaten; thus when one cooks with eggs, one should check the eggs."
25. One could question whether, according to Jewish law, the checking by the USDA is sufficient to satisfy the custom to check eggs, or maybe Jews have to check the eggs for blood spots, according to the custom. It would appear to this writer that this is a classical case of a professional being believed because of the rabbinic rule that a "professional does not undermine his livelihood" by lying about his product. The American public does not want eggs with blood spots, and that is why the companies do not sell such eggs. In addition, there is an explicit USDA regulation, which create a situation of dina demalchuta, adding to the credibility given.
26. In free range eggs (as nearly all chickens were in the time of the Ramo) blood spotting occurs in nearly 4% of the eggs (E-mail communication from Professor Don Bell, Poultry Specialist, University of California).
27. Rabbi Moshe Tendler notes, in a letter to this writer, that "when eating hard boiled eggs, Rav Feinstein would peel off the 'white and check the surface of the yolk for blood spots, which would appear as black spots."
28. Consider two other examples where checking practices have changes due to changes in reality; checking tzitzet (see Yechave Da'at 6:1 for a survey of this issue) and checking food for insects (Iggerot Moshe OC 1:91 and YD 2:25 note that changes in reality change the obligation to check for insects).
29. See Rabbi Zushe Blech, "Industrial Eggs" at www.star-k\articels\eggs.html. He notes that "the processing of eggs is monitored by factory workers, not the mashgiach, and with thousands of eggs being processed every hour, it is impossible to guarantee absolutely no blood [spots]." Rabbi Zushe Blech notes, in an e-mail to this author, that "liquid egg cracking companies occasionally use fertilized eggs. It seems that chicken breeding companies produce a substantial inventory of fertilized eggs, and depending on the market, may have no need to convert them into chickens. At this point - providing they have not sufficiently developed - they are sold to egg crackers." It would seem that even these types of eggs are kosher; however they are more closely governed by the custom of the Ramo that such eggs be checked, as a relatively high percentage of them (perhaps as high as 10%) will have blood spots. Rabbi Michael Morris, OU Rabbinic Coordinator for a number of egg companies in America, noted that while there is no mashgiach present when eggs are produced in a commercial setting, there is a key operator present at the egg cracking machine whose job is to examine every egg for blood spots and other abnormalities, and who can discard any given egg if a blood spot is found. The egg manufactures have a vested interest in insuring that no eggs with blood spots are used.
30. Shulchan Aruch Yoreh Deah 66:5.
31. Indeed, a claim could be made that even the minhag quoted by Ramo to check eggs no longer needs to be observed in America. As noted, in the time of Ramo 4% of all eggs had blood spots, and some of those blood spots were the result of fertilized eggs, creating a Torah prohibition. Even in that case, halacha did not mandate that one had to check eggs, but merely that the custom was to check when one can. Even Ramo admits that when one cannot check, one does not have to, and one should not refrain from eating eggs that one cannot check (such as at night). However, since the problem rate was close to 4%, the minhag was to check, and not rely on the majority of cases when one need not, as one in every twenty five cases was an exception. Presently maybe even the minhag to check need not be followed, as the problem rate in grade a or AA table eggs is markedly lower (generally thought to be one in 1000 table eggs), and thus even the minhag is not applicable. Changes in reality can cause changes in customs; see Rabbi Daniel Sperber, Minhagai Yisrael volume 1, at pages 12-45.

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