Monday, January 12, 2015

The Curious Case of Beaver Testicles

This medieval illustration depicts a hunted beaver biting off
its testicles to escape the fate that has befallen its friend
Did you know that when you hunt a beaver, it will save itself by biting off its testicles and throwing them at you?

As a recent article in Wired magazine discussed, this was a widespread belief in the medieval period. It wasn't as crazy as it sounds. Beavers were indeed being hunted for their testicles, which were thought to have medicinal benefit, along with internal pouches called castor sacs (which were also thought to be testicles), from which a substance called castoreum is harvested. In the same way as certain lizards will shed their tails as a payoff for predators that want to eat them, it was believed that beavers will sacrifice their testicles in order to escape with their lives.

Reader Akiva M. drew my attention to this belief also being found in rabbinic writings. Yehudah Aryeh Mi-modena (Leone di Modena, Italy 1571–1648) mentioned it in his book of ethics, Tzemach Tzaddik. This fascinating work lists the various character traits of man, both good and bad. For almost all of them, the author gives an analogy from the animal kingdom. His interests were drawn to the extraordinary; the creatures that he mentions include the basilisk, which kills by sight; the mermaid, which lures sailors to their deaths; and the immortal phoenix. But he also mentions many real animals, to which he attributes extraordinary qualities, in line with standard medieval beliefs. In the entry on the quality of peace, di Modena writes as follows:
The castor sacs of a beaver,
often confused for testicles
Go and observe the trait of peace in the animal known as castoro (the beaver, Castor fiber), which instinctively knows that hunters pursue it for its testicles, which possess excellent medicinal properties, as is known. Therefore, when it finds itself hunted with no way of escape in any direction, in order to save itself it severs its testicles with its teeth and casts them down, so that the hunters will take them and he can be in peace.
This is not, however, the only reference to beaver testicles in rabbinic literature. To my mind, it is not even the most interesting reference. That honor belongs to a very brief comment by the thirteenth century French scholar Chezkeyah b. Manoach, better known by the name of his commentary on the Torah, Chizkuni.

In parashas Re'ay, there is a list of ten kosher land animals. Sixth in the list is the yachmor. As discussed in the forthcoming Torah Encyclopedia of the Animal Kingdom, there is evidence that this is the hartebeest, which became extinct in eretz Yisrael long ago. Others identify it as a fallow deer or roe deer. More far-fetched suggestions, proposed in the nineteenth century, include the wildebeest (R. Yosef Schwartz, Tevuot HaAretz p. 364 and Divrei Yosef p. 64–65) and moose (Shalom Yaakov Abramowitz, Toledot HaTeva vol. 1 p. 400). These are indeed kosher animals, but neither of them lived anywhere near biblical lands.

But by far the most extraordinary suggestion is that of Chizkuni, who translates the yachmor as bivra, which means beaver. Quite aside from beavers not living anywhere near biblical lands either, there is a more serious problem. As R. Yosef Schwartz points out, the beaver is not remotely a kosher animal!

Why did Chizkuni identify the yachmor as a beaver? In his comment, Chizkuni refers us to the Gemara, Bechoros 7b, which refer to the "eggs" (testicles) of the yachmor. The Gemara's statement occurs in an extensive discussion regarding whether various animal products are permitted for consumption. Certain animal products are considered to be waste matter rather than food; accordingly, if for some reason a person wanted to eat them, he may do so even they do not come from a kosher animal. Conversely, some products of kosher animals are not permissible for food, if the animal from which they are derived is still alive, due to the prohibition of eating any part of a kosher animal that has not been slaughtered. With these principles in mind, the Talmud discuss the status of certain mysterious secretions produced by the yachmor:
With regard to the clumps (that are secreted) by a yachmorta, the Rabbis proposed that they were eggs (or: testicles) and were therefore forbidden (for human consumption, since they are a detached part of a living animal). Rav Safra said: It was really the seed of a stag which sought to mate with a hind, but since the hind’s womb is narrow it rejected it, and thus the stag pursued the yachmorta, but its seed had already congealed (and is thus excreted as clumps; and since seed is classified as mere waste matter, it is not forbidden for human consumption). (Bekhorot 7b )

The phenomenon described by the Talmud is not recorded in contemporary zoological studies, and it is difficult to correlate it with any known phenomena. Animals such as deer, antelope, and hartebeest have various scent glands that can produce waxy secretions, but these would not appear to be the egg-like “clumps” discussed in the Talmud. The only clumped products from kosher animals that might be used for food are bezoar stones. These are masses found in the stomach or intestines of animals, especially ruminants, and in particular the bezoar ibex. Bezoar stones were used to make antidotes for poisons. However, it is difficult to claim that these are the subject of the Talmud’s discussion, since the Talmud indicates that these objects are secreted by the animal, whereas bezoar stones are extracted from the animal after its death.

In any case, we see that the Gemara talks about an animal called the yachmor producing testicle-like objects that are consumed by humans. Accordingly, Chizkuni presumed that the reference was to the beaver, from which castor sacs are taken for medicinal purposes and as a food additive.

Incidentally, this still occurs today. Castoreum is sometimes used as artificial vanilla flavoring. In the US, it can be listed on a product's ingredients as "natural flavors". This is why food requires kosher certification!

To my mind, the latter reference to beaver testicles is much more interesting than the former. Believing that beavers bite off their own testicles to throw at attackers is merely one of many common medieval misconceptions about animals, that is easily accounted for. Believing that the beaver is a kosher animal, on the other hand, is truly bizarre; beavers were very common animals in France. If anyone has an explanation for it, please let me know!

On a related note, The Torah Encyclopedia of Animal Kingdom is nearing completion. The writing, editing and photograph selection are all finished, the first round of proofreading has been done, and the layout is almost complete. Thanks to the generous support of many people, most of the book is already sponsored, but there are still funds that need to be raised for this extremely elaborate project. If you would like to make a dedication, please be in touch. You can download two sample chapters, on the leopard and hyrax, at this link.


  1. Very interesting, thanks.

    Is the encyclopedia going to be the 4 volumes it was projected to be (as stated in the link?) Are there lots of pictures? When do you estimate it will be COMPLETE complete, meaning, actually available for purchase?

    1. It will probably be three volumes. Yes, there are lots and lots of pictures. I hope that the first volume will be available for purchase within a few months.

  2. Reginald is home with the fluJanuary 13, 2015 at 5:53 AM

    Although your discussions of Chazal getting the science wrong is always interesting, perhaps you'd like to dedicate a future post to where Chazal get the science right (Getting it right to our surprise, that is.)

    1. It appears to me that it wasn't just the Chazal who got it wrong -- (just about?) everybody in those days got these things wrong. I doubt that Chazal always went out and investigated these matters for themselves; rather I think they mostly just adopted whatever were the prevailing scientific opinions on things. What they brought down was what they thought was the best knowledge that was available. Is there any evidence that they, as a matter of practice, did their own investigations and experiments? For if they did, and still came up with these results, then we could blame them. But just adopting what they thought, what they could determine to be, was the most reliable information is what we still do today.

  3. Incidentally, this still occurs today. Castoreum is sometimes used as artificial vanilla flavoring. In the US, it can be listed on a product's ingredients as "natural flavors". This is why food requires kosher certification!

    I find this doubtful:

    1) It is highly unlikely that any mass-produced processed food that you eat that might have a hechsher contains Castoreum. See

    In 2011, the Vegetarian Resource Group (VRG) queried five companies that produce vanilla flavorings about whether they used any castoreum in their products, and all five replied that they did not: All five unanimously stated that castoreum is not used today in any form of vanilla sold for human food use. One company, in business for ninety years, informed The VRG that they have never used castoreum in their products. "At one time," we were told by a senior level employee at this company, "to the best of my knowledge, it was used to make fragrance and still may be." A major ingredients supplier told us this about some of their vanilla flavorings: "[Castoreum] is not a common raw material that is used and we don't use it, so I can safely say that our natural vanilla flavors do not contain any animal juices. All vanilla extracts are free of it, too, wherever you go."

    2) How is it that people throughout history ate bakery bread, drank beer and spirits, bought oil, or ate Bishul Akum when it is permitted (e.g. for "non-royal" foods)? Did they have certification?

    The main reason for certification on non-meat foods is likely consumer ignorance (of which I plead guilty) of what is in the food we eat and what permitted by halachah. Hence the certifications for water and detergent.

    1. And rice, whole grains and spices, dishwashing liquid.... Under consumer pressure and with the appearance of two competing agencies, a local certification agency which has been issuing hashgachas to every one on request and a for a nominal fee finally issued a list of items that do not actually need their Passover hechsher for Passover.

      While one may not have to worry about castor...since vanilla beans are now far cheaper and artificial vanilla flavour is easy to emulate...some red food coloring may contain components from certain insect shells whose pigments are more powerful than anything made in a lab.

      A question: Does cooking oil require certification as the process always involves cold pressing on exclusive equipment? There is a brand of Ukrainian sunflower seed oil that, unlike the North American overly-filtered, de-flavoured variants is delightfully thick and pungent with sunflower-ness....

    2. I am not a Rabbi and not competent, so ask someone who is before you do anything.

      That said, the fact that is says 100% Sunflower Oil on the package is probably enough without needing cold pressing or exclusive equipment. (Again review line 1 of this post before you act).

      If you rely on Rav Abadi and sons, then you can post your question here:

      Browse around for his general approach, for example, see this one:

      Subject: General Question on Kashrut

      Message: Why, according to several of the posts on this forum, is Gatorade considered kosher when it has no hashgacha whatsoever? Moreover, why are several other products without certification ruled as kosher (ie, Dunkin' Donuts from a non-certified establishment), even for Passover in some situations (eg, Trident gum)? Furthermore, on what grounds do you wantonly go against the ruling of an organization such as the OU (re: Stella D'oro Swiss Fudge cookies on 12/18/2002)? What are the rationales behind these rulings?

      Reply: Behind these rulings are the Gemarah, Rishonim, Shulchan Aruch etc.
      We know that even if there is a Hashgacha on the product we still have to check the ingredients. Because, as I'm sure you are aware, there are always different products listed in the many different newspapers and newsletters about unauthorized kashruth symbols or no 'D' on dairy products. If we check the ingredients we are secure that we are following the Halacha that Rav Moshe says, we can trust the companies when something is in writing.
      Do some searches on the website, you may see some eyeopening situations.

    3. Also, based on the website that you posted, David, it would appear that castoreum is being added solely for aromatic purposes (although the website isn't absolutely clear). This could be another reason to be lenient (if it were used with enough regularity to warrant concern). I am also not a Rabbi, but it doesn't appear to actually add flavor, despite the fact that it would be listed under "natural flavors." Can any reader comment further on my assertion that may know more about this topic, please?

  4. "Bezoar stones were used to make antidotes for poisons."

    I am disappointed there was no further reference to a well-known modern work of fiction, where bezoar stones appear as a minor plot point.

    1. His interests were drawn to the extraordinary; the creatures that he mentions include the basilisk, which kills by sight; the mermaid, which lures sailors to their deaths; and the immortal phoenix.

      Not to mention the basilisk which was a major plot point of one of the volumes of that work of fantasy, or the immortal phoenix, which might arguably be considered a character in that work

  5. Perhaps the statement is trying to "kasher" castor oil by claiming that it somehow came from a kosher animal originally, much as, say, honey from a bee was "kashered"? In other words, they weren't saying that a beaver was kosher, only that its "byproducts" (as they saw them) were.

    Of course, if it was used for medicine, it wouldn't have to be kosher, but it's an added plus if it happens to be. I believe the castor oil plant was an early substitute anyway.

    Who's publishing the Encyclopedia?

  6. Fascinating post. I would spell the animal's name "yachmur" (see Devarim 145:5):

    אַיָּל וּצְבִי, וְיַחְמוּר; וְאַקּוֹ וְדִישֹׁן, וּתְאוֹ וָזָמֶר

    1. Make that Devarim 14:5, of course.

  7. This view by the Chizkuni appears to make little sense in reality nor is required in interpreting a Gemara. That Gemara in Bechorot 7b doesn't conclude that 'cheili d'yachmura' refers to 'eggs', but to congealed semen. The Chizkuni must assume like Rashi that the testicles were found by themselves and invokes the medieval folklore about a beaver. Rashi aside, it seems likely that the Gemara is initially referring to a Bezoar found in a dead yachmor - particularly if an idex is a biblical yachmor. The question is then, is it integral to the animal and therefore treif (since the animal was a neveila), or is it a waste product and kosher. I see no indication from the Gemara that it is a material external to the animal. It is either an undigested ball of grazing material (bezoar) or some congealed semen (according to Rav Safra) found in the yachmor.

    I agree with JXG, reference to the Bezoar should invoke its use in Rowling's Potter series as a 'universal' poison antidote. I had thought that she simply made this up. Now I learn that it was based on old folklore just like the Basilix and Phoenix that she uses.

    Y. Aharon

  8. Rabbi Slifkin,

    When you refer to "waste products" of non-kosher animals that may however be consumed... Can you please clarify what you mean by "waste". Is this limited to secretions, excretions and regurgitations from the animal (honey from bees?) or can it be understood to include parts of the body that would not normally be consumed (or that would need substantial processing prior to consumption - yes, bone derived gelatin)?

  9. Rabbi Slifkin, can you please write another post soon? I realize that animal lovers (and doctors) must deal with all sorts of issues related to anatomy. For the rest of us, though, these issues make us a bit uncomfortable and queezy.


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