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Getting Into The Thick of Things - Gelatin
by Rabbi Avrohom Mushell, Star-K Kashrus Administrator


Have you ever had a slice of p’tcha galarita - that spicy, globby stuff Bubby used to cook up? How did she manage to make it so thick?

Better yet, open a can of gefilte fish. Look at the stiff jell that comes as its broth. Why is it that when you cook your own gefilte fish, you do not get that solid jelly from your broth?

Did you ever wonder why theirs is so thick and yours is not?

COLLAGEN may be the answer to this thickening question.

Collagen is a fibrous, insoluble protein that makes up a major portion of bone, skin and connective tissue. By cooking animal bones or adding fish bones to the broth of your gefilte fish, you will extract some of the collagen from the bones. This gives you the wobbly jelly in p’tcha or in the gefilte fish that comes in a can.

The most common form in which collagen is marketed is partially hydrolyzed state known commonly as gelatin. The word gelatin comes from the Latin word gelatus, meaning stiff or frozen. Gelatin stiffness is measured in units called Bloom. This refers to a measuring device developed by a man named Oscar T. Bloom. High bloom refers to a higher molecular weight of the gelatin, which provides a stiffer consistency. Different applications will require different bloom levels.

Gelatin Uses
Gel Desserts Marshmallows
Ice Creams Toffees
Gummy Bears Vitamins
Throat Lozenges Frostings
Low Fat Items Capsules
Sugar Glazes Yogurts
Emulsifiers Protein Supplements


With the commercialization of food processing, this versatile ingredient has shown its usefulness in a variety of foods. We may well be aware of its use in producing jelly-like confections from Jell-O to Gummy Bears. However, the usefulness of gelatin goes beyond that. Gelatin is fat free, yet it leaves a smooth feeling in your mouth, similar to that of fat. This effect is very useful as an additive to foods that are marketed as low fat. Gelatin also acts as an emulsifier, helping to distribute fat and add stability to confections. This is beneficial in toffees or spreadable frostings, creams, yogurts and ice creams. Adding gelatin can make a candy last longer, since gelatin does not break down as quickly as sugar. This makes the addition of gelatin ideal for throat lozenges. Similarly, hard sugar glazes will stay white and not run when gelatin is added. Gelatin can hold shape when aerated to create light and fluffy marshmallows. In vitamins and medicines, gelatin can be used as a coating to mask a bitter taste or as a capsule to contain the powders. Some use plain gelatin as a protein supplement to their diet. All in all, gelatin is remarkably versatile and ideal for the manufacture of many processed foods and confections. The only question to the kosher consumer is, Can one use foods containing gelatin?”

The answer, in short, is that it depends upon the source of the gelatin. As previously mentioned, gelatin is made by extracting collagen from the bones and skins of animals, and skins or scales of fish. Most commonly, the gelatin made from animal products is not manufactured from kosher or kosher-slaughtered animals. There are several questions that must be addressed in order to understand the halachic status of gelatin. To begin with, the Torah prohibits eating the meat of those animals or fish designated as tamei (unclean/non-kosher). Examples are pigs, horses, catfish, and sharks. Meat of an animal that is tahor (clean/kosher) and not properly slaughtered is prohibited by the Torah as nevela. Do these prohibitions also apply to the bones and skin of the animal? If the prohibitions of nevela and tamei were to apply to the skins and bones, can this status be altered through the process used in manufacturing gelatin? Lastly, if the animal source for the gelatin is kosher, does it retain the properties inherent to its source? Is such gelatin considered a meat product, rendering it forbidden to be cooked or eaten with dairy products? If the source is fish, can it be used together with meat? The Shulchan Aruch (Yoreh Deah 116:2) states that one may not eat fish together with meat, as it is considered unhealthy. This is based on the Gemora, which teaches that meat which is cooked with fish causes disease. Does gelatin extracted from fish carry this restriction?

In reference to the question as to whether or not the processing alters the status of the meat, we may cite a similar question discussed in Yoreh Deah (87:10). It used to be the common practice to make cheese curd by adding the skin of a calf's stomach to milk, or by letting the milk sit in a calf's stomach. The Rema states that where the stomach has been salted and dried to the extent that is like a piece of wood, and milk is subsequently added, one would be permitted to use the resulting cheese. The Shach notes that although one may use such milk products, it is not proper to do this intentionally. The Pri Megadim notes that the Rema's leniency applies specifically to the stomach of an animal which contains less meat flavor, and not to regular meat. The Pri Megadim adds that the Rema allowed this only where the stomach was removed from the milk after a short time, and was not heated together with the milk. If the stomach stays for a period of over 24 hours, or if it is heated with the milk, it would absorb the meat flavor which would render it forbidden for use.

These statements were made in reference to dried kosher meat parts, which were kosher and did not carry a prohibition. The fact that they were dried prevents them from attaining a prohibited status when mixed with milk. This may not be the case when the source is not kosher. There is a rule that states, "That which comes out of an unclean (non-kosher) source remains unclean (non-kosher)." If so, we should say that the by-products of a non-kosher animal retain their non-kosher status.

As to the question regarding whether hides are considered to be meat, Horav Moshe Feinstein zt"l addressed this issue in Igros Moshe (Yoreh Deah Vol 1 #37). He writes that animal hides are not considered to be meat (prohibiting its mixture with milk) by Torah law; they are, however, prohibited with milk by rabbinic law. If they are dried and processed, the resulting gelatin is not included in this rabbinic prohibition. Therefore, gelatin produced from kosher slaughtered animal hides may be intentionally used with milk, provided that the hides are cleaned in order to remove any meat residue.  Some opinions disagree with Horav Feinstein's conclusion, most notably Horav Aharon Kotler zt"l, who concludes that gelatin produced from kosher hides is considered to be a meat product. However, there is room for leniency when dealing with gelatin that is derived from kosher hides, as the gelatin has little or no taste. Therefore, it can be nullified in pareve ingredients which would result in a pareve product. (This does not contradict the rule ein m’vatlin issur lechatchila, as it is heter.) However, gelatin from non-kosher hides retains its forbidden status.

It must be noted that we have not addressed the question of blood in or on the hides. We know that blood is prohibited for consumption by Torah law.  This is why we salt our meats prior to cooking. There is a question regarding animal hides, and whether or not we assume there is blood absorbed in them which must be removed. To satisfy all opinions, one would be required to salt the hides prior to processing.

The question of whether or not the bones of a non-kosher animal carry the same prohibition as the meat is discussed in Yoreh Deah (99). The Shulchan Aruch maintains that the bones of a prohibited animal are kosher and would, in fact, count as part of the permitted food, in constituting a majority of sixty kosher parts. The Rema maintains that although the bones themselves are not prohibited, they do not count as part of the kosher percentage when mixed with other kosher food. The Shach quotes the strict view that the moisture in the bones of non-kosher animals is not kosher; only dry bones are viewed as kosher. Some rabbinic authorities interpret the collagen as being part of the natural liquid of the bone, which was prohibited by the Shach.

It should be noted that even the Shulchan Aruch was only talking about the actual bone itself, not the marrow of the bone, which is treated as meat and is prohibited. Furthermore, if the bone was already cooked with non-kosher meat or bone-marrow, it is rendered unkosher.

As you may have deduced from the above information, in order to produce gelatin from a non-kosher animal bone, it may only be done with cleaned and dried bone, without any marrow or soft tissue. Rabbinic authorities note that one cannot assume that the manufacturer’s process alone will be pure enough to produce gelatin in a kosher manner. We should also take into account the opinions that the collagen in the bone is prohibited as part of the animal’s liquids. All things considered, one should refrain from consuming gelatin from a non-kosher animal. Indeed, this is the practice of most reputable kosher certifying organizations. Where the source of the gelatin is a kosher animal, there are still logistical problems to overcome. Aside from the prohibitions of tamei and nevela, as previously noted, we must also be concerned with the prohibition of treifa. This refers to the Torah's prohibition against the consumption of animals that possess certain injuries or disorders. Since most of the inspections conducted to determine if the animal is treifa are done after the slaughter and skinning of the animal, the hides must be tracked to be sure that treifa hides are not mixed with kosher hides. For this reason, meticulous supervision is needed to oversee production. As with any kosher food, it must be produced on kosher equipment. If the processing is to be done in a non-kosher plant (as is usually the case), the equipment must be cleaned and kosherized before kosher production.

Similarly, fish gelatin must be produced from a kosher species of fish if it is to be considered kosher. The use of fish gelatin with meat foods poses an interesting question. As previously noted, the Shulchan Aruch (Yoreh Deah 116) prohibits the cooking of meat and fish together due to health concerns. We tend to be more stringent when dealing with possible health issues than with concerns of issur (prohibited substances). Therefore, there is a question among the commentaries as to whether or not the rule of one in sixty nullification applies to unhealthy substances just as it does with prohibited substances. The custom is that unhealthy substances become nullified at a ratio of 1 to 60 (see Nekudas Hakesef, Yoreh Deah 116 & Pische Teshuvah).

There are many reasons for leniency in the use of fish gelatin together with meat. Many rabbinic authorities are of the opinion that the nature of some foods has changed, thus rendering the mixture of meat and fish no longer unhealthy (see Magen Avrohom Orach Chaim 173:1, Teshuvos Chasam Sofer vol:1 #101). Furthermore, there is a rationalization that not all fish would be considered a dangerous mixture with meat. It may be that only the type mentioned in the Gemora (Binita) is unhealthy (see Pische Tshuvah, Yoreh Deah 116:3). It may also be maintained that the unhealthy aspects of fish cooked with meat are found in the flesh of the fish, and not in their skin, scales and bones (from which gelatin is made). Since gelatin may not have fish flavor, it may not harbor the harmful effects that fish may carry (see Pische Tshuva, Tshuvos Sride Eish vol:2 #67 re. cooking beef in fish oil). With this same reasoning, we can say that gelatin can be batel (nullified) with a majority of other food ingredients and can be eaten with meat (according to R' Aharon Kotler, zt"l regarding animal gelatin and milk). For these reasons, it may be considered generally acceptable to use products containing fish gelatin with meat, or we may use the same reasoning to allow products containing animal gelatin with fish.

In summary, gelatin produced from tahor species that are properly processed (slaughtered, internally checked, and salted in the case of animal source) and produced on kosher equipment is acceptable.

Gelatin Substitutes Agar Agar, Carrageenan
Gums & Thickeners Gum Arabic, Carob, Guar, Karaya, Pectin, Tragacanth, Xanthan


In today's market, there are reliably kosher gelatins available from both animal and fish sources. There are other gelatin substitutes that are not animal or fish based, which have properties similar to gelatin and can serve in its stead. Common among them are Agar Agar and Carrageenan, made from sea vegetation. Agar Agar or Katen is derived from a red algae known as gelidium comeum. Agar Agar has strong setting properties similar to gelatin. In fact, unlike gelatin which needs refrigeration to set, Agar Agar will gel at room temperature. Gels made from Agar Agar are affected by acidity more than gelatin. Thus, one may find that fruity deserts made with Agar Agar are more likely to turn watery. Carrageenan, also known as Irish Moss, is a reddish purple seaweed. Its jell is not as stiff as gelatin or Agar Agar, but it is quite useful as an emulsifier as well as a gelling or thickening additive. There are other vegetable derivatives that can serve to replace gelatin as stabilizers, emulsifiers, or thickeners. Pectin, used in jams and jellies, is a complex carbohydrate extracted from apple pulp and citrus rinds. There are many other vegetable gums that can be used, as well. Amongst them are the gums of Guar, Carob, Gum Arabic, Tragacanth, and Karaya. Guar is a legume commonly found in Pakistan and India. Gum arabic is derived from the sap of acacia trees found in the Sudan and West Africa. Locust bean gum extracted from carob beans (buxser) is common in the Middle-East and the Mediterranean. Tragacanth gum is gathered from the sap of the astragalus shrub common to Asia. Karaya or Sterculia gum is from the sterculia tree found in India. Xantham Gum, often seen as an ingredient in kosher salad dressings and the like, is not of plant origin. It is produced by the microbial fermentation of a carbohydrate with the xanthomonas campestris organism. Gelatin substitutes are also making headway in the field of vitamin and medicinal capsules.

So, when you want to get into the thick of it, or if you want your dessert to gel, there are alternatives that do not compromise good kashrus standards.



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