• March 30, 2023
  • 8 5783, Nisan
  • פרשת צו

Is Your Chicken Kosher?

Is Your Chicken Kosher?

When we check food for the “kosher” label, what are we really looking at? In this course Rabbi Dr. Stuart Fischman will guide you through what factors go into determining whether chickens are kosher and why some people might label something as kosher that others would say is not.

May 7, 2013 5:00 pm - 6:00 pm
Is Your Chicken Kosher?: Lesson 1
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Hello Everyone, Today was an introduction to the laws of treifot. We saw that the realities of poultry farming have changed during the past 50 years. Whereas throughout Jewish history there was an assumption that chickens are treifah-free this may no longer be the case (at least according to some authorities). Today chickens are raised in crowded coops where they have very little room to move , they receive vaccinations during the “chick” stage of their growth, and they are exposed to viruses that apparently did not affect the chickens of our granparents’ (or perhaps even our parents’ ) time. Because of these changes many authorities claim that we can no longer ignore the possibility of treifot in poultry.I hope you enjoed today’s shiur. I realize that these shiurim will introduce many of you to a new vocabulary. I will try to make myself as clear as possible. Please feel free to ask questions both during the shiurim and afterwards via e-mail. Thank-you, Stuart Fischman


May 14, 2013 5:00 pm - 6:00 pm
Is Your Chicken Kosher?: Lesson 2
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Hello Everyone, Today we discussed two subjects. First we discussed the definition of the word “treifah.” In modern usage “treif” means anything that isn’t kosher, we say “shrimp is treif.” But this is not accurate. “Treifah” means that an animal suffers from a terminal disease or injury. It is important to keep in mind that the “treifah” applies to live animals who suffer from this type of injury. Once the affected animal dies from the injury , it is a “n’veilah.” So for our purposes, an animal which suffers from a perforation in its heart is a “treifah” and killing it via shechitah will not make it kosher. When this animal dies it is a “n’veilah.”

After we covered these basic ideas we discussed a contemporary issue involving treifot and milk. An animal that is treifah may not be eaten, but its milk is also prohibited as well. One of the treifot listed in the Mishnah in Chullin is a perforation in the “inner stomach.”  An old question (it goes back at least 200 years ) is how to judge animals which had abdominal surgery for digestive problems. On the one hand these animals most certainly had their stomachs perforated, on the other hand they heal and live on many years giving milk ( We will discuss later the question of whether the healing of an injury makes the animal kosher again . For today’s purpose we took the position that “treifah” is irreversible).One authority, Rav Menashe Klein zt”l ruled that given the incidence of bovine surgery (between 5-15% of cows in dairy herds) and the ease of determining which cows had surgery (farmers keep veterinary records) there is no excuse to consume milk without appropriate rabbinic supervision ( and this has nothing to do with the question of Chalav Yisrael)

We also saw material provided to me by the OU. The OU examined this issue and came to the following realizations. First, not every cow treated for displaced abomasum (“indigestion” of sorts) is treated in a fashion which makes it treifah. Second, it is not at all easy to ascertain which cows were treated and how they were treated. To put it briefly the records are not as a ccurate as described by Rav Menashe Klein zt”l. Since the majority of cows are not treated for displaced abomasum we can say that the treated cows are “batel b’rov”  and since we cannot easily ascertain which of the cows were treated (in order to remove them from the milk supply) we can ignore them.

Chag sameiach to all, Stuart Fischman

May 21, 2013 5:00 pm - 6:00 pm
Is Your Chicken Kosher?: Lesson 3
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Hello Everyone,

First of all I want to thank everyone who takes  the trouble to attend the live shiur. Your participation helps to make the shiurim more “real” for me.

Today we saw concepts that are important not only for the laws of treifot, but for our understanding of the Torah in general

The shiur began with a look at how the mitzvah of treifot is explained ( or rationalized) by the Rishonim. The Rambam in Moreh HaNevuchim says ,briefly, that the treifot are all a prelude to the death of the animal. The Sefer HaChinuch expands on this idea. He writes that the body is the tool of the soul. It is by acting via the body that the soul can carry out its good intentions. Since this is the case it is in Hashem’s  interest that we be physically healthy . Therefore Hashem gave us mitzvoth which will keep us healthy and the dietary laws fall into that category. And even if we do not understand how exactly the dietary laws keep us healthy we need to remember that Hashem’s wisdom is greater than ours; only a fool would claim otherwise.

The Sefer HaChinuch goes on to make an important point . Hashem never tells us in the Torah a definite answer to the “why” of the mitzvot.    We can all find meaning in mitzvoth, but nobody can claim to have the meaning of a mitzvah. If this were so, the next step would be a person saying that the mitzvah is no longer relevant. Unfortunately we have seen this to be the case with the Reform and Conservative movements doing away with mitzvoth that do not appeal to them.

The Ramban gives an alternative view of treifot and the dietary laws in general. He writes that the dietary laws are given for our spiritual well-being, the foods that Hashem forbade cause coarseness of the soul.

We next saw the discussion about how the list of treifot came into being and if it is open to modification.  The Gemarah says that the outline for the rules of treifot are הלכה למשה מסיני and we see that there were discussions about adding to the list of treifot. We also we read in the Mishnah

זה הכלל כל שאין כמוה חיה טרפה:

and  we know that many of the defects listed as treifot are treatable.

Many authorities have addressed this apparent conflict between the rules of Halacha and what we observe in every day life. Even in the Gemarah we see people questioning particular types of treifot based on the fact that animals suffering from the particular treifah have lived over one year (and the rule is that no treifah survives for a year). The Chazon Ish writes that the history of the Jewish people is divided into epochs lasting 2000 years. The second epoch was the epoch of Torah and it ended with the deaths of Rav Ashi and Ravinna who were the final authorities of the Talmud Bavli. The Chazon Ish views the composition of the laws of treifot, and indeed the entire corpus of the Oral Law as something organized by the Sages who had רוח הקודש . Significantly, the Chazon Ish writes that Hashem in His wisdom chose to withhold certain medical knowledge from us during the 2000 year period of Torah. Following the end of the 2000 year long period of Torah we cannot tamper with the received Oral Law. That is why advances in science cannot influence the decisions reached by חז”ל. Thus the חזון איש makes a very sharp distinction between the paths taken by the Torah and by secular science.

The Rashba was asked by someone how to judge  an animal that reportedly has lived for more than a year with an extra limb. On the one hand, extra limbs make the animal a treifah, but on the other hand it is written that treifot do not survive for a year. The Rashba replies that anomalies of this sort are discussed in the Gemara. He explains that the “one-year” rule is applied to resolve cases of doubt, if we don’t know if a particular pathology causes “treifah” we can wait to see if it survives a year. However if an animal suffers from a pathology specifically listed as a treifah then its status as a forbidden treifah cannot be challenged. The Rashba says that even if many people would testify that the animal has survived for a year we will not accept their testimony. Just as the Gemara explains, we can reject the testimony as being the result of error, confusion or even a malicious desire to mock the Torah. The Rashba advises people never to debate Halacha with people who have “an agenda.” Only people well-versed in Torah should engage in debates of this sort; lay-persons should not get involved in these discussions.[1]

In a similar vein, we saw the anonymous comment in the Tur attesting to the survival (and thriving) of animals whose stomachs were perforated as part of veterinary treatment. This was cited to prove that a particular position in the Gemara is incorrect. The Bach in his commentary rejects this position totally, and says this sort of evidence cannot be accepted in a Halachic discussion.

[1] Those of you who listen to the Sunday shiur on Chovot Halevavot know that Rabbeinu Bachya holds that we are all obligated to become well-versed. I don’t think he disagrees with the Rashba about the inadvisability of the ill-informed to debate principles of Halacha.

May 28, 2013 5:00 pm - 6:00 pm
Is Your Chicken Kosher?: Lesson 4
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Hello Everyone,

First, as always I want to thank all the people who come to the “live” shiur. It really does mean a lot to me that you make this effort.

Today we finished the introductory set of shiurim which addressed the fundamentals of treifot. We saw until now that the principles of treifot , the list of conditions and their manifestations are considered to be set rules of Torah Sheb’al Peh. As the Rashba expresses this, anyone who tries to contend that an animal that has a treifah has lived for over a year with this condition is just wrong.

Today we examined in a little more detail the question of whether or not being a treifah is a reversible condition. We started with the discussion about perforations of the lungs. An animal with a perforation of the lung is a treifah. The Gemarah says that healed perforations of the lungs and the esophagus are nonetheless treifot. Nevertheless the Gemarah says that if the lung is perforated in a spot where the perforation adheres to the interior of the thoracic cavity (and these adhesions are known as “sirchaot”) the animal is kosher.

This raises two questions:

  1. a) What distinguishes healed lesions in general from adhesions between the lungs and thoracic cavity lining?
  2. b) Can we generalize from the leniency of adhesions between the lung and thoracic cavity lining?

Rashi explains what distinguishes the “kosher adhesion” from the “treif adhesion.” Rashi says the “kosher” adhesion is immediate and immediate because of its anatomical location. Other adhesions are flimsier and will eventually detach from the lung bringing back the perforation.  It is not clear if Rashi so to speak “closes the door” on the possibility of other adhesions being “kosher.”

There is an argument along these lines between two of the great Sephardic Rishonim. Rabbi Aaron HaLevi (known as הרא”ה) notes that the Gemarah only mentions “treif” scar tissue ) קרום שעלה על המכה ) in  the context of lungs and the esophagus. This being the case, the only healed treifot which remain treif despite their healing are the lungs and esophagus, The Rashba emphatically rejects this. The Rashba insists that treifot, even if they heal, remain “treif”

The Rashba’s great teacher, the Ramban, apparently disagrees. The Ramban , based on a paradox that is raised by the Gemara, makes the following observation: if a cow’s knee  tendons are severed (the צומת הגידין) the animal is treif. If on the other hand the cow’s leg is severed above  the knee , the animal is kosher. The Gemara resolves this paradox saying  that we cannot apply the usual rules of reasoning by analogy to treifot.

Based on this paradox and its resolution the Ramban raises this possibility: if an animal is made treif by having its knee tendons severed it can be made kosher again by severing the leg above the knee. The Ramban asserts that an animal which is  treif can be made kosher again proving this assertion by citing the case of lung adhesions. An animal is made treif when its lung is perforated and made kosher again when the adhesion forms which closes the perforation.

The Rashba who insists that treifot are irreversible provides an interesting reply to the Ramban. The Rashba says that if the Gemara says that an adhesion is kosher then that perforation was never treifah to begin with![1]

After reviewing these principles we went on to examine the question of cows who have undergone surgical treatment for various gastro-intestinal ailments. We saw last week that an anonymous commentator to the Tur wrote that it is a fact (in the fifteenth century) that animals have  their stomachs perforated routinely to treat stomach ailments and these animals recover and thrive. The anonymous commentator writes that these cases of therapeutic stomach perforation proves that these particular perforations do not cause treifot (contrary to the opinions of the Gemara and Poskim). The great commentator to the Tur, Rav Yoel Sirkes, (known as the בית חדש or ב”ח ) says this anonymous comment should be removed from the Tur, we absolutely do not decide questions of treifot on the basis of practical observation.

In the late nineteenth century Rav David Tzvi Hoffmann (the Rosh Yeshiva in Berlin) was asked about surgically treated cows. In his work of response (שו”ת מלמד להועיל) he says one can rule leniently on the basis of the principles we mentioned:

  1. a) The רא”ה rules that healed perforations are not treifot (unless they occur in the lungs or esophagus)
  2. b) Rashi explains that adhesions are not considered as a “cure” for treifot because they ultimately rupture. This is simply not the case with surgically repaired perforations. These repairs are long-lasting; they certainly last well past the twelve-month benchmark for treifot. Rashi and even the Rashba never ruled that such forms of healed perforations are treifot.
  3. c) Since there are various opinions in the Gemara about where in the stomach does a perforation make the animal treifah, the animals in question are “doubtful” treifot . tThe rule is that when a doubtful treifah survives for 12 months the doubt is resolved favorably.

So we have seen in this תשובה how empirical observation applied in conjunction with the classical rules of Halacha are applied to reach a conclusion to a modern issue.

[1]  Keep in mind that Rashi says that “kosher” adhesions form immediately

June 4, 2013 5:00 pm - 6:00 pm
Is Your Chicken Kosher?: Lesson 5
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Hello Everyone,

Today we began the discussion of “glatt.” As is well-known, the word “glatt” means “smooth” in Yiddish (and according to “Google Translate” this is true for German and Swedish as well). The “smoothness” (“glattheit” in German, again according to Google) refers to the surface of the animal’s lungs. The Gemarah in masechet Chullin rules in apparently unambiguous fashion that if on the surface of the lungs there adhesions which connect one lobe of the animal’s lungs to a distant lobe the animal is not kosher.

The Shulchan Aruch, following the Rashba records this as the final law.

Despite the apparently unambiguous nature of the ruling in the Gemarah , in Northern Europe (“Ashkenaz”)the custom was to attempt to dissolve (or even detach) these adhesions (which are known as “sirchaot”). The Rashba and Shulchan Aruch condemned this Ashkenazic practice in the strongest terms; they wrote that whoever  practices this custom is guilty of feeding non-kosher food to the the Jewish people. Even the Rema, who wrote the standard Ashkenazic commentary to the Shulchan Aruch was hard-pressed to find a basis for this widespread custom.

So what is the basis for Askenazic practice of removing adhesions? The 13th century authority, Rabbeinu Asher (known as the “Rosh”) writes in his commentary to Chullin, that the custom is based on the writings of the post-Talmudic Geonim. From a story about Rav Yakov Gaon it is possible to ascertain that the Geonim recognized two types of adhesions. There are firm adhesions which cannot be easily broken and these are the “sirchaot” which render an animal a “treifah.” Then there are fragile adhesions which can be separated easily from the lungs or dissolved. These adhesions are merely accumulations of mucous and are Halachically  benign.

So today we saw how a custom that is apparently in violation of the Gemarah was defended by the Ashkenazic Rishonim. I mentioned during the shiur the writings of the late Professor Yisrael Ta-Shma z”l. In his great work מנהג אשכנז הקדמון he explains the great authority given to minhag in Ashkenaz. According to the Rashba, almost all the Ashkenazic Jews were eating treif.  This contention was absolutely unacceptable to the ashkenazic authorities. It cast an aspersion on the piety of their ancestors and needed to be refuted. The Rosh shows how the custom evolved from a post-Talmudic source (the story of Rav Yakov Gaon).

In the next shiurim we will see more examples of how customs regarding treifot are attacked and defended by various authorities.

June 11, 2013 5:00 pm - 6:00 pm
Is Your Chicken Kosher?: Lesson 6
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Hello Everyone,

Thank you for attending today’s shiur, I’d like to send  a special welcome to Joseph Schlink who is new to the shiur.

Today we finished our discussion about “glatt” meat. As we saw already there are two broad schools of thought about “glatt.” One opinion requires that the lungs be free of all adhesions except for the type specifically permitted by the Gemara. This is the opinion of the Shulchan Aruch, which quotes the Rashba and rules that anyone who deviates from this rule is feeding treifot to the Jewish people.

The other opinion holds that despite the rather arbitrary nature of the rules of treifot, these rules can be interpreted.

We saw that Rashi and his grandson Rabbeinu Tam disagreed about the kashrut of a particular type of sircha and their disagreement reflected these two approaches. Rashi (supporting the view of his teacher) held that a particular sircha is kosher even though the Gemarah never discusses this type of sircha[1]. Rashi felt that it would correct to analyze why a particular type of sircha is ruled to be  kosher in the Gemarah and then see if another type of sircha meets the criteria of the Gemarah. Rabbeinu Tam rejects this method of ruling on treifot. He accuses Rashi (his revered grandfather) of feeding treifot to the Jewish people[2] and says that to rule on a novel question of treifot one needs “proof” to establish a leniency and  (apparently) logical arguments are not “proof.”

The practice among Ashkenazi Jewry we know was to adopt a more “flexible” approach to “sirchaot.” We learned last week that Ashkenazi authorities distinguished between adhesions that could be dissolved and those that could not; only the latter type were ruled to be forbidden sirchaot. Today we learned about a later development in Ashkenazi practice. In the 18th  century Ashkenazi shochtim began to peel sirchaot off of lungs and then to test the lungs for air-leaks. If no air leaked out of the lungs they would rule that the animal is kosher.

This new practice created a storm of controversy but it became widely adopted. The question was put before the great authorities to see if this novelty could be justified. The Aruch Hashulchan   provided one explanation[3]. Based on the experience of tens of thousands of cases he said that it is impossible to say that every sircha that has been peeled off from a lung masked a perforation, since these lungs never leak air.[4] So the Aruch Hashulchan (based on early texts) says that sirchaot can be divided into two  Halachic categories based on their size. The ancient texts describe forbidden sirchaot as being the width of one ,or at the most, two fingers. The Aruch Hashulchan notes that when the shochet peels off these narrow sirchaot they do lead to air-leaks. On the other hand, wider sirchaot peel off easily and cleanly from the lungs and do not lead to air-leaks. The conclusion that he arrived at is that narrow sirchaot are indeed outgrowths from the lungs (and treif)  while broad sirchaot are out growths from a membrane which adhered to the lungs. These broad sirchaot are not the sirchaot forbidden by the Gemarah.

So that is the discussion of glatt. Besides being informative I hope these shiurim gave you all an insight in how the Gemarah is interpreted by our great Poskim and how they sometimes arrive at different conclusions after reading the same texts.

[1] This sircha is called מאומא לאונא . The Gemara says the only type of sirchaot that are kosher are of the מאונא לאונא variety.

[2] There really is no “middle ground” with treifot.

[3] The earlier authority, the Chatam Sofer, offered a similar defense of the practice.

[4] And we saw several weeks ago in our study of abdominal surgery and its impact on treifot that not all authorities admit empirical evidence into a discussion of treifo

June 18, 2013 5:00 pm - 6:00 pm
Is Your Chicken Kosher?: Lesson 7
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Hello Everyone,

Today we began a discussion about the kashrut requirements of chickens. Chickens are not different in principle from cattle since both species are governed by the laws of treifot. Nonetheless there was an important difference in practice between the procedures governing chickens and cattle. The difference lay in the process of examining chickens and cattle for the presence of treifot.

As we saw already,   the Mishnah in masechet Chullin presents us with a long list of treifot. Even though any one of those treifot render an animal forbidden we have no obligation to look for treifot. The reason for this is that the Torah permits us to manage our religious lives on the basis of well-founded assumptions[1]. Experience shows us that most animals do not suffer from treifot, so I am allowed to assume that the animal or chicken which has been properly slaughtered is kosher and I have absolutely no obligation to examine it for treifot.

There is however an ancient[2] custom to examine the lungs of cattle for סרכאות. Rashi explains that even though most cattle do not have סרכאות, since there is a significant [3] incidence of סרכאות in cattle we need to examine the lungs of every animal that is slaughtered. The Pri Megadim[4] adds that the Torah permits us to ignore “the minority” when the search for it is  burdensome. Since סרכאות do not occur in poultry there was never a custom to routinely check the lungs of poultry.

However, as the saying goes, that was then and this is now. In our times the procedures for raising poultry have changed radically. Now chickens are raised in crowded coops. They have no room to roam and stretch their legs, they are fed steroids and other  supplements to accelerate their growth, and they receive inoculations to prevent the their catching various diseases. All of these factors have (according to many authorities) raised the incidence of treifot among chickens to above the Halachically significant threshold percentage. Treifot (particularly treifot of the leg sinews known as צומת הגידין) need to be searched out.

We saw that the Chief Rabbinate of Israel recognizes three levels of kashrut in the poultry industry. The highest level is called [5]חלק. Next comes מהדרין and then “merely” kosher. The distinctions between these levels of kashrut extend from the procedures for inoculating the chicks on the poultry farms[6],to the rate of shechitah at the poultry plant and finally the procedures for examining the chickens for treifot.

Naturally, חלק poultry is more expensive than non-חלק, and this reflects the more careful (and therefore slower and less profitable) steps taken in guaranteeing the kashrut of the chicken.

Next week we will discuss, bli neder, in more detail the rationales of the various Hashgachot and how they view the incidence of treifot.

PS- Over the past few days there have been difficulties for some people in logging on to the Web Yeshiva site with the various browsers. The tech staff has been working to fix the problem.

[1] In Hebrew these types of assumptions are labeled as רוב and חזקה.

[2] Allusions to it are to be found in the Gemarah as well as in the Midrashic literature.

[3]  I hope that we next week will discuss the precise definition of “significant.”


  1. Joseph son of R. Meir Teomim was born in 1727 in the village of Steritz, near Lvov (Lemberg), Poland (nowadays it is in Ukraine). He lived with his parents in Lemberg where his father was a judge and preacher. R. Yoseph studied with his father, and at the age of 18 had already published his own novellae at the end of the published volume of his father’s novellae. Around the year 1744 he married and moved to Komarna where he served as a grade-school teacher, while his essential occupation was the study of Torah and writing his books. In 1765 he had already published two of his first volumes: Porat Yoseph on some tractates and the Ginat Veradim on the principles of the Talmud. In 1767 he relocated to Berlin and studied and authored his books in the study hall of the wealthy Daniel Yaffe. In 1774 he accepted the position offered by the lay leaders of Lemberg to full his late father’s position as decider of Jewish Law (posek) and as preacher, remaining there for seven years. In 1781 he was appointed the Rabbi of Frankfort on the Oder in east Germany where he passed away in 1792. R. Joseph is famous for his compilation Pri Megadim on the Shulkhan Aruch, Orach Chaim and Yoreh De’ah, which have become one of the primary explanations to this code of Jewish Law. There are super-commentaries on it, as well as abbreviated versions. The commentary on Orach Chaim is comprised of two parts: the Mishbetzot Zahav on the Taz [Turei Zahav] by R. David haLevi and the Eshel Avraham on the Magen Avraham by R. Avraham Gombiner and was first published in Frankfort on the Oder in 1786. The commentary on Yoreh De’ah is comprised of the Mishbetzot Zahav on the Taz and the Siftei Da’at on the Shach [Siftey Cohen] by R. Shabbtai Cohen, and was first published in Berlin in 1771. Nowadays, the Pri Megadim is published at the end of each volume of the Shulkhan Aruch in almost every edition, and in some modern editions can be found on the very folio of the code. In addition to the Pri Megadim, R. Yoseph Teomim authored many other volumes, including Rosh Yosef on tractate Hullin; Shoshant Ya’akov on the principles of the Talmud; Tevat Gome (on Gemorrah, Midrash, and Aggadah) and is a commentary on the Torah using Halakha and midrash (first published in 1882 in Frankfort on the Oder); Matan Secharan shel Mitzvot investigating issues of reward and punishment, and many more. Some of his compilations are lost. The Responsa Project now contains the Pri Megadim on Orach Chaim according to the Machon Yerushalayim edition of 1994, on Yoreh De’ah according to the Goren Ornan Institute edition, Jerusalem 2004, and the Tevat Gome according to the Mishor edition, Jerusalem 2007.

[5] And even though originally the word חלק only applied to cattle whose lungs are free of adhesions, the term has acquired the meaning of being “flawlesslykosher.”

[6] So in Israel there are indeed “Glatt Kosher eggs” since the eggs come from a poultry farm where the חלק /Glatt form of inoculation is followed

June 25, 2013 5:00 pm - 6:00 pm
Is Your Chicken Kosher?: Lesson 8
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Hello Everyone,

I want to thank you all for making the effort to attend the shiur on a fast-day. I hope that the zechut of our learning today will help speed up the גאולה.

Today we began the study of one of the most subtle concepts in Halacha- the concept of “frequent” (מילתא דשכיח, מיעוט המצוי).  We learned last week that when we need to make decisions about the permissibility of something, for example if an animal is kosher or treifah ( in the narrow technical sense that we are studying) the Torah allows us to decide on the basis of the “majority.” In this case since the majority of animals are not treifot I may assume that the animal in question is not a treifah.  Based on this majority we are excused from having to examine the animal that we wish to eat to ascertain that it possesses any of the 18 defects which would render it a treifah.

We also learned last week that there is one exception to this rule. We are required to examine the lungs of animal for lesions. And this is so even though the majority of animals do not suffer from lung adhesions. There are three reasons for this requirement:

  1.   a) examining the animal’s lungs is not inordinately difficult[1]
  2. b) not to examine the animal’s lungs would give the appearance that we are shirking our religious obligations
  3.   c) lesions of the lungs are “common.”

This last reason has generated much controversy- how common is “common?” At what point may I no longer rely on the “rov”| and have to examine what I eat? We saw one example from the laws regarding insects. Fruits or vegetables which are “commonly” infested must be examined individually for infestation, and even if most of my sample is insect-free I must examine the remainder as well. The ש”ך writes that ruling of the Rema is based on the precedent  regarding the inspection of the lungs.

So we need to ask again, how common is “common?”

We saw two opinions today on this matter ( and bli neder we will see more next week). The first opinion is that of Rav Yakov of Karlin, author of the [2]משכנות יעקב. Rav Yakov provides a numerical value to the concept of “common”-it equals an incidence of 10%. When the incidence of a “problem” is greater than 10% it cannot be ignored.

Rav Yakov derives this figure from the area of commercial law. The law states that when a person buys a large number of barrels of wine he must assume that a certain number of barrels will contain wine that has gone bad. He must assume this risk and cannot claim that if even one barrel is bad he was the victim of fraud. The law is that the purchaser assumes the risk that 10% of the barrels contain wine that has gone bad. It follows that if a purchaser of wine cannot claim that a 10% spoilage rate is unexpected (and therefore cannot ask for his money back) if I know that a certain form of treifah occurs in 10% ( or more) of animals I cannot pretend that its incidence is unexpected. Instead I must search for it whenever I wish to eat meat.

Rav Shmuel Wosner[3] shlitah is the author of the works שבט הלוי. He disagrees with the position of the משכנות יעקב. He questions the comparison of wine souring to treifot in general. He also points out that none of the early authorities provided a quantifiable definition for the term “common” which is something that we could have expected.

Rav  Wosner’s definition of “common” is is not mathematical. He writes that an occurrence can be defined as “common” if it occurs spontaneously, and is neither place nor time dependent. The only time that we can be lenient is when the occurrence is exceptionally rare     ( מיעוטא דלא שכיח). Rav Wosner bases this assertion on the Gemarah[4] which says that even though animals are squeezed as they pass through the birth canal, we are not concerned that animals are made into treifot by the possible compression of vital internal organs. Even though such treifot may occur, their incidence can be ignored.

Rav Wosner’s interpretation obviously leads to requiring  a more stringent level of examination for treifot.

Next week , bli neder, we will see more ideas on this subject.

[1] Most of the shiur was devoted to defining “common.” We also spent some time discussing the parameters for the concept of “difficult.” We saw the teshuvah of Rav Moshe Feinstein zt”l who wrote, based on the Rambam that to examine a chicken for treifot  would be considered “difficult’

[2] He lived in the 18th  century but unfortunately has no entry in Wikipedia

[3] Shmuel Wosner

From Wikipedia, the free encyclopedia

Shmuel (HaLevi) Wosner (Hebrew: הרב שמואל הלוי וואזנר; born 6 September[1] 1913) is a Haredi rabbi and posek (“decisor of Jewish law“) living in Bnei Brak, Israel.

Wosner was born in 1913 in Vienna, Austro-Hungary and studied in the Yeshivas Chachmei Lublin of Poland led by Rabbi Meir Shapiro. He was also a student of Rabbi Shimon of Zelicov who was the official supervisor at the Yeshiva. In Vienna, he had known and befriended the Rabbi Chanoch Dov Padwa of Galicia.[2]

He married and immigrated to Palestine before the Holocaust and dwelled in Jerusalem where he studied at the Dushinsky Yeshiva. It was in that time that, in spite of his young age, he became a member of the Edah HaChareidis. When he relocated to Bnei Brak, upon the incentive of the Chazon Ish, Rabbi Dov Berish Widenfeld of Tshebin, Rabbi Isser Zalman Meltzer and RabbiYitzhak HaLevi Herzog he established his “Yeshiva Chachmei Lublin” bearing the same name as the one in Lublin where he studied in his youth.[3]

He is the author of several works of Jewish law, such as Shevet HaLevi (“The Tribe of Levi”), a comprehensive series of Halachic rulings and responsa on Jewish laws comprising ten volumes and several other Torah books all bearing the same name.

His sons include Rabbi Chaim Wosner, formerly dayan of London‘s Satmar community, who has since moved to Bnei Brak to assist his father in the management of the Yeshiva. He has another son Rabbi Bentzion Wosner of Monsey, New York, who is the av bet din of the Shevet Halevi beis din.[4]

Wosner had a sister, Sophie Welwart, living in Deerfield Beach, Florida and Staten Island, New York.[5] Welwart died on 22 January 2011 in New Jersey[6]

On May 20, 2012, Ichud HaKehillos LeTohar HaMachane ran an “asifa” (gathering), at Citifield in New York City, on the dangers of the Internet. There Wosner spoke via live hookup from Israel to 60,000 Orthodox Jews. He barred unfiltered Internet use for the Jewish community except for business purposes so that people can still earn a living.

[4] And the interpretation of ר”ן.

July 2, 2013 5:00 pm - 6:00 pm
Is Your Chicken Kosher?: Lesson 9
Class description

Dear Everyone,

Hello again.

Today we completed our discussion about chickens. We saw that over the centuries the kashrut of chickens was taken for granted. However over the past 40 years or so many questions about the kashrut of poultry have arisen, Due to the changes in way chickens are raised anatomical  changes in chickens have begun to appear, and if in the past it was assumed that chickens do not suffer from a significant percentage of treifot this assumption may no longer be valid.

Some authorities endorse the checking of every chicken for treifot, and some recommend examining a sample of chickens as they are delivered from each poultry farm. We saw that the question of relying on a sample to determine the kashrut of a “whole” has been debated about 150 years ago.  The Halacha is that wheat grains which become wet and then swell and split are chametz. So what’s to be done when it rains on an attic-full of wheat? Ideally a person would sift through the entire pile of wheat, grain-by-grain , and remove all the tainted grains. This is obviously extremely tedious. The Aruch Hashulchan writes the “common custom” is that the local rabbi examines  “a few” handfuls of wheat and if the tainted grains are less than 1/60 of the sample then the entire attic-full of wheat may be used on Pesach.

The Chatm Sofer [1] says that this method of examining the wheat is totally wrong. As the Chatam Sofer puts it, there basically two types of “problems” which  require examination, problems whch are “dynamic” and problems which are “static.” A “dynamic” problem is insect infestation of fruit. Insects multiply, so when a collection of fruit is suspected of being infested I need to examine each piece of fruit, a clean sample of fruit tells me nothing about the other pieces of fruit. Grains of wheat are “static.”  If I find a few pieces of grain in a pot of soup on Pesach I do not need to assume that there are more pieces of grain waiting to be found inside the pot. The Chatam Sofer writes that when it rains on a pile of wheat , its status is analogous to infested fruit. Just as it is impossible to know the extent of insect-infestation in a pile of fruit, it is impossible to know how much wheat was dampened by the rain. Therefore sampling the wheat does not prove the kashrut of the entire pile.

It may be that the various attitudes of kashrut supervisors towards poultry reflects the attitudes of the Aruch Hashulchan and Chatam Sofer. Some authorities view treifot in chickens as totally unpredictable, and since there are instances of 70% treifot we always need to fear such occurrences. Others concede that the incidence of treifot is unpredictable , but by examining the first 1000 (for example) chickens from a 20,000 chicken delivery we get an accurate picture of the entire delivery.

We concluded with an essay by Rav Dessler zt”l from Michtav Me’Eliyahu. We saw many disagreements among the poskim in questions about treifot. It is amazing to encounter such strongly opposing views (kosher or treif) when one side (e.g. the Mechaber  and Rashba) say that the opposing side (Ashkenazic Jewry) is eating treif. Even Rabbeinu Tam said that anyone who follows the ruling of his grandfather (Rashi!) is eating treif. How can this be? Why on Earth  wouldn’t Rabbeinu Tam accept the ruling of his grandfather?

Rav Dessler explains that our use of the word “Halacha” (to define the set of   rules that guide our behavior) is not precise. A rule can be called “Halacha” only  if it is known with great precision and exactitude . For example[2] the Halacha says that the ink used to write tefillin must be black. This rule is not questioned by anyone, and nobody will ever question it.[3] However, most rules of Jewish life are not known with such clarity. Over the centuries laws have been forgotten, errors have crept in to the chain of tradition.  Disagreements have arisen over details of observance[4].We still follow these laws but they no longer have the authority of “halacha” which cannot be questioned. These rules have the status of “minhag” (custom). Rav Dessler writes that it is the duty of a scholar to examine the minhagim in order to restore them to their original , precise, and accurate state. For this reason Rabbeinu Tam felt that it was within his authority to say that the rules of his grandfather (Rashi) for assembling the parshiyot of tefillin were wrong. Similarly we saw that Rabbeinu Tam said that Rashi and Rashi’s teacher erred in their ruling on treifot of the lungs.

We of course are taken aback when we see  Rabbeinu Tam reject the opinion of his legendary grandfather. So Rav Dessler explains that Rabbeinu Tam was only fulfilling the mitzvah of learning Torah when he examined the issues of tefillin and treifot. Torah must be studied which all of a person’s intellectual ability, and the person must study honestly , objectively and impartially. If his conclusions are different from those of his predecessors, then so be it.[5]

[1] Who was writing about 50 years to the Aruch Hashulchan

[2] This my own example

[3] This may be an exception to the “never say never” rule.

[4] While nobody claims that fires can be lit on Shabbat, there are disagreements about opening bottles on Shabbat

[5] It should go without saying that this freedom to disagree needs to be  earned

July 9, 2013 5:00 pm - 6:00 pm
Is Your Chicken Kosher?: Lesson 10
Class description

Hello Everyone,

Welcome to our last shiur of the z’man. Today we discussed turkeys.  This may come as a surprise to many of you, but one of the pre-eminent poskim of the 19th century, Rav Shlomo Kluger zt”l ruled that it is absolutely forbidden to eat turkey. Today we saw why turkeys were so controversial.

When we look at parashat Shmini (Vayikra, chap. 11) we see the well-known criteria for determining the kashrut of animals (split-hooves, ruminant) and fish (fins and scales). When it comes to birds[1] the Torah gives us a list.  We are presented with a list of non-kosher birds. This leaves us free to eat any bird that is not on the list.

This situation obviously leaves the non-ornithologists among us in a quandary. If I do not know how to identify the non-kosher birds, what birds may I eat? So Chazal present us with a list of four characteristics which identify kosher birds:

  1. a) they have a crop, b) they have a gizzard which can be peeled, c) they have an “extra” toe[2] d) they do not “trample” on their prey[3].

Any bird which possesses these four characteristics is kosher.

Rabbi Zerachiah HaLevi (known as the “Ba’al HaMa’or) added another set of criteria. He wrote that he received from his elders that any bird which has webbed-feet and a wide bill does not trample on its prey.









This  seems very straight-forward.  When I meet a new bird (like a turkey):



I need only to check it for the four signs of a kosher bird.

The problem with eating a new species of bird is the opinion of Rashi. Based on a story from the Gemarah, Rashi notes that we need to know that the bird does not trample its prey and how can we ever know this? The answer is that, of course, we cannot. So Rashi says we can only eat a bird which via tradition we know that this bird does not trample its prey.

So this dispute is reflected in the Shulchan Aruch. Rav Yosef Karo writes that if we encounter a new species of bird it can be eaten either if we know it has all four signs of kashrut, or if it meets the criteria of the Ba’al HaMa’or. The Rema writes that we only eat birds which we know by tradition that they are kosher.

Over the years various questions about species of water-fowl were brought to the Ashkenazi poskim, some forbade new species (since they do not have a tradition) and others rely on the Ba’al HaMa’or.

This is a duck (obviously) and the tradition says duck is kosher:

Does the tradition rule that this is a duck?


This is a chicken ( and chickens are kosher by tradition):



But what does the tradition say about this?

So Rav Shlomo Kluger ruled that the tradition regarding chickens has nothing to do with “this bird that was brought from America.” Therefore, Ashkenazim may  not eat turkey.

So how did turkey “become “ permitted?

We saw an essay by Rabbi Ari Z. Zivotofsky who provides an interesting explanation. Sephardic  Jews can eat birds once they establish that it possesses all four signs of kashrut. It may be that Sephardic Jews in Western Europe and Turkey saw turkeys and observed that they are not birds of prey[4] and possess the anatomical signs of kashrut. After they established a tradition of eating turkey, Jews from Eastern Europe “spread the word” about this new bird and it became accepted. No less an authority than Rabbi Naftalu Tzvi Berlin zt”l (known as the “Netziv”) observed that turkey has become known as a kosher species of fowl even though when it first became known in Eastern Europe it was the subject of controversy.

So that’s why we all eat turkey.

I want to thank everyone who participated in these shiurim . I hope that you all found them as much fun as I did. I look forward to meeting with you again in Elul. Have a wonderful summer, Stuart Fischman

[1] And grasshoppers too, but maybe we will leave them alone for now

[2] For an illustration of the “extra finger” and other terms from the shiur please look at the source pages on the web-site.

[3] The Hebrew word is דורס, and there are several opinions as to what this means.

[4] Unless you’re a worm

Rabbi Dr. Stuart Fischman graduated from Yeshiva University in 1980 and the dental school of Columbia University in 1985. In 1989 he began studying and teaching at Yeshivat Hamivtar and now studies and teaches at Yeshivat Machanaim in Efrat. He has rabbinic ordination from Rav Zalman Nechemia Goldberg.