Halakhot of Kashrut
Based on a shiur by Rav Yosef Zvi Rimon
Translated by David Silverberg
The Torah mentions two prohibitions concerning the consumption of the meat of kosher animals: neveila and tereifa. A neveila is an animal that died naturally or was improperly slaughtered. A tereifa is an animal that underwent proper shechita but suffered from a defect as a result of which the animal would not have survived for more than twelve months.
We should point out that today, animals very often receive injections in their internal organs, and these injections can cause punctures in an organ that renders the animal a tereifa. In Israel, all veterinary treatments are supposed to be conducted under supervision. Nevertheless, one must take note of this point. We should also bear in mind as we discuss these halakhot that even the milk of a tereifa is forbidden for consumption.
According to the halakhot of tereifa, technically speaking, whenever an animal undergoes shechita, all its internal organs must be checked to ascertain that it had not suffered from any illness that would render it a tereifa. But Halakha follows the view that in practice, not all the organs need be checked, since we may rely on a "rov hamatzuy" (statistical overwhelming majority), that most animals are not tereifot. Certain limbs, however, are injured more frequently and thus require checking. The Shulchan Arukh (Y.D. 39:1) rules that we consider perforations in the lung a relatively common occurrence, thus necessitating the checking of the lungs of every animal after shechita.
The Gemara in Masekhet Chulin (46b) discusses the concept of a "sircha" (generally translated as "adhesion"). This term refers to a thread on the lung that extends into the animal's plural cavity. In such a case, there is the possibility of a perforation underneath the thread; should it fall off the lung, the animal becomes a tereifa by virtue of the puncture in the lung.
Some views distinguish between two different types of sircha. If the sircha does not become detached or crushed when a person squeezes it, then it renders the animal a tereifa. If, however, one can crush the sircha, then we assume it to be merely a secretion of some sort, and the animal is not a tereifa.
The Mechaber and Rama debate this point. The Rama rules (Y.D. 39:13):
"Some permit feeling the sirchot and crushing them, claiming that an [actual] sircha will not become detached even if a person crushes it all day long. Therefore, whenever it is crushed, we may assume it permissible, claiming that it is only a secretion, rather than a sircha. Although this constitutes a great leniency, all the people of these countries have already adopted this practice, and one should not object to them."
By contrast, the Shulchan Arukh writes (Y.D. 39:10):
"Whenever a sircha in the lung is forbidden, it makes no difference if the sircha is thin as a hair, or thick and firm and wide as a thumb, as opposed to those who crush it with a hand and assume it permissible if it can be crushed. Whoever follows this practice is considered as if he feeds Israel tereifot."
Rav Ovadya Yosef brings this position as the final halakha, in both Yechaveh Da'at and Yabia Omer.
In conclusion, there is room for Ashkenazim to act leniently in this regard, though it is certainly appropriate to make a point of eating only "glatt" (literally, "smooth," without any adhesions) meat.
Gelatin is a substance used in many different materials that assists in hardening the given material. There is a protein called collagen found mainly in the skins and bones of animals. This substance is dissolved in hot water, and when the water cools, a gel-like substance forms. In theory, any bone can be used as a raw material for the manufacture of gelatin, but the procedure is particularly complex.
Generally, the procedure involves drying the bones, in which case they become unsuitable for consumption. The collagen is then separated from the calcium, and the water is evaporated, leaving behind a white, tasteless powder.
Today, the production of gelatin uses the bones of non-kosher animals. Seemingly, then, we should forbid the consumption of gelatin outright. However, the Gemara in Masekhet Avoda Zara (67b) establishes that when a forbidden food becomes inedible, it loses its status of issur. Accordingly, we might permit the consumption of gelatin on the basis of the fact that it loses its status of issur in the interim stage, when it is inedible. On the other hand, the gelatin becomes once again edible at the end of the procedure, and thus its previous status of issur perhaps returns.
A different Gemara, in Masekhet Temura (31a), writes that although the egg of a tereifa-hen is itself forbidden as a tereifa, a chick hatched from this egg is permitted for consumption. The Gemara explains that just before the egg hatches, the egg becomes rotten and inedible. It thus loses its status of issur, which does not return once the egg hatches and a chick emerges. Rav Chayim Ozer Grodzensky (Achiezer 3:33:5) concludes on the basis of this halakha that the interim stage suffices to permanently eliminate the status of issur. He adds that in our case, we deal with bones, to which no Torah prohibition applies in any event, and we therefore have even more room to rule leniently. We find a similar approach in Rav Tzvi Pesach Frank's Har-Tzvi (vol. 3).
Many other Acharonim, by contrast, forbid the consumption of gelatin. Rav Moshe Feinstein (Iggerot Moshe, Y.D. 2:23) forbids the use of gelatin because although it indeed becomes inedible, it does so only temporarily with the specific purpose of enhancing its edibility. It therefore never loses the formal status of "food." This is also the position of the Minchat Yitzchak (5:5). These authorities maintain that even the rule of bittul (the negation of a minority ingredient by virtue of the small proportion it constitutes) does not permit the consumption of foods containing gelatin, since ingredients used as stabilizers are not subject to bittul.
Today, many places have begun – for reasons entirely unrelated to kashrut – producing a new form of gelatin from skins. Generally, gelatins made from skins are even more halakhically problematic than those produced from bones. Recently, however, there have been attempts to produce gelatin from leather shoe soles. Rav Moshe Feinstein claimed that this type of gelatin poses less of a problem because processing the substance for purposes of making shoes divests it of its status as "food," and this is not merely an interim stage intended to enhance the food's quality.
There is a substance called "vegetable gelatin," but this refers not to gelatin, but rather to a vegetable stabilizer used in place of gelatin; gelatin can be extracted only from animals.
When we find kosher certification on products containing gelatin, it means that it may be eaten according to the lenient position mentioned above. There exists a type of a gelatin made from fish, but given the difficulty in manufacturing it, this form of gelatin is used very rarely.
Blood in the Liver
In Parashat Re'ei, the Torah introduces the prohibition against the consumption of blood: "Make sure that you do not partake of the blood; for the blood is the life, and you must not consume the life with the flesh" (Devarim 12:23). The Sefer Ha-chinukh (mitzva 148) explains that although we eat meat, we do not eat with it the "nefesh," meaning, that which gives life to the flesh. The Torah wanted that when we eat meat, we remember that we deal with a formerly living creature. The Ramban explains the prohibition against eating blood as stemming from the fact that we offer it upon the altar when bringing sacrifices.
Practically, the halakhic problem of blood arises most commonly with regard to the liver, which contains a lot of blood. Regular meat also contains blood, but only an amount that can be removed through the process of melicha (salting). The amount of blood in the liver, however, is too high to allow for its removal through melicha. Strictly speaking, blood absorbed into the meat is not forbidden for consumption; one may, therefore, eat raw meat without any process of kashering. If, however, a person wants to eat cooked meat, then he confronts the problem of blood: in the process of cooking, the absorbed blood leaves the meat, returns to its forbidden status, and then reenters the meat and renders it forbidden. One must therefore kasher meat before cooking it.
The liver can be kashered only by roasting it. If one roasts a whole liver, he must cut a deep slice along the entire length to allow the blood to leave during roasting. One need not cut slices when roasting small pieces of liver.
The Mechaber and Rama (Shulchan Arukh, Y.D. 73:1) write that one must first rinse the liver before roasting it. The Shakh (13) notes, however, that if one did not first rinse the liver, it is still permissible after roasting. The Rama adds that one should sprinkle some salt on the liver, but once again, neglecting to do so does not render the liver forbidden, since the main kashering procedure is the roasting. Needless to say, one should not place large quantities of salt, as the salt will then become filled with blood which may result in the blood's return into the liver, thus rendering it forbidden.
For how long must a liver roast for the kashering process to be effective? The Mechaber (ibid.) rules that it must roast for half the time required to prepare it for eating, the period known as "ma'akhal Ben Drusai," at which point the food can be eaten under extenuating circumstances. Since we cannot determine this amount of time with precision, the Acharonim ruled that one must roast the liver until it becomes suitable for consumption. The Rama adds that one must rinse the liver after roasting.
It is important to remember that the stove and everything around it become non-kosher by this process, since boiling hot blood falls upon it. It is therefore customary and recommended to use a separate grill for roasting liver.
The poskim addressed the issue of whether liver can be kashered in an oven. The Tzitz Eliezer and others were inclined to permit kashering liver in an oven, but once again, one must bear in mind that everything in the oven becomes non-kosher as a result of this process. Additionally, a tray must be placed at the bottom to absorb the blood so that it does not render the entire oven non-kosher.
Blood in Eggs
The Gemara states in Masekhet Keritut (20b):
"The Rabbis taught: 'You shall not eat any blood' – I might infer [that this includes] even the blood of those who walk on two [legs], the blood of eggs, the blood of grasshoppers, the blood of fish – everything is included? The verse says, 'of a bird or of an animal'… I exclude the blood of eggs which are not a species of flesh."
This Gemara indicates that the blood of eggs is permissible for consumption, since we do not consider eggs a "species of flesh." To what does the Gemara refer when it speaks of the "blood of eggs"?
The egg-yolk constitutes the main part of the egg, whereas the egg whites serve as the protective covering around the yolk. The yolk itself consists of two parts: the cell of the egg, which contains storage of food, and a second section, where the chick develops. The chick develops only if the egg had been fertilized by a male.
Tosefot in Chulin (65b) comment that when the Gemara speaks of blood in eggs, it refers to the blood that signifies the beginning of the chick's formation. The blood is nevertheless permitted according to Torah law because it does not yet qualify as a "species of flesh," since no flesh has yet to be formed. Chazal forbade the consumption of this blood, but as far as Torah law is concerned, the egg is permissible.
Rashi there explains that when an egg contains this type of blood – the blood of the initial stages of the chick's formation, the egg is forbidden according to Torah law, as this indeed qualifies as a "species of flesh."
The Shulchan Arukh (Y.D. 66) follows Rashi's view, that the consumption of this blood violates a Torah prohibition, and therefore, in such a situation, one must discard the entire egg. In se'if 3, the Shulchan Arukh adds that this applies only when the blood is situated on the yolk or on the seam connecting the yolk with the egg white. The Rama, however, records the practice to forbid the egg's consumption even if one finds this blood on only the white section.
How would this view explain the Gemara in Keritut, which permits blood found in eggs? According to this position, the Gemara refers to the blood of "beitzim muzarot" (literally, "peculiar eggs"), which the Gemara mentions elsewhere, in Masekhet Chulin (64b): "Beitzim muzarot – a hearty soul will eat them." This term refers to eggs that did not result from fertilization by a male, and will therefore never develop into a chick. If one finds blood in such an egg, he may discard the blood and eat the egg, and to this the Gemara in Keritut refers when it permits the blood of eggs.
The Shulchan Arukh (Y.D. 66:7) rules, "Beitzim muzarot – even if a hen sat on them for many days, one may eat them, so long as he discards the blood." What is the halakha today? Generally speaking, eggs today are not fertilized. May we rely on this assumption and permit all eggs in which we discover blood?
The Gemara says in Masekhet Beitza (7a-b) that when a rooster has no chance of reaching the hen, we may assume the egg to be unfertilized, and we need not concern ourselves with the possibility that the hen's egg might have been fertilized. Rav Moshe Feinstein (Iggerot Moshe, Y.D. 1:36) and Rav Ovadya Yosef (Yechaveh Da'at, 3:67) write that today, we may consider all eggs "beitzim muzarot." Even if fertilized eggs might also end up on the shelves together with unfertilized eggs, they undoubtedly constitute the minority and are hence "batel be-rov" (negated by the majority). However, Rav Moshe adds that although this is true according to strict halakha, nevertheless, since this does not entail considerable financial loss, it is proper to discard the entire egg. Rav Ovadya upholds Rav Moshe's ruling where one can purchase eggs at a low cost. But in our locations, he writes, eggs are expensive and one may therefore discard the blood and eat the rest of the egg.
Practically speaking, fertilized eggs must be checked for blood. If, however, one did not check an egg, he may rely on the statistical probability that most eggs do not have blood. Unfertilized eggs do not, strictly speaking, require checking, but Jewish women have nevertheless adopted the practice of checking all eggs and this is a proper custom from which one should not deviate.