The Treatment of Raw Materials
The vast majority of gelatin products produced in the world come from either bovine bones and hides or pigskins. A detailed description of what takes place during production can be found in chapter 2 of my father’s book, Expositions in Jewish Dietary Laws (Ktav; 2010). What follows is a brief description of how bovine gelatin is manufactured:
Contrary to what the public is often told, industrial level bovine gelatin and collagen are not produced from meat or marrow; they are only produced from inedible bones or hides. The proteins found in meat and marrow are different from those found in bones and hides and if included will decrease the quality of the finished product. The companies that produce gelatin and collagen go to great lengths to ensure that all traces of meat and marrow are thoroughly removed before production. Bones and hides themselves are not considered meat and have been excluded by Chazal from any category of forbidden food. In the words of the Rishonim and Achronim they are nothing more than “Eitz B’Alma” (“mere wood”) or “Afar B’Alma” (“mere dirt”). Those who assert that industrial level gelatin and collagen are produced from meat or marrow are simply unfamiliar with the actual manufacturing guidelines or purposely misleading the public.
In the case of bovine hides, the hides are first transported from the slaughterhouse to a tannery. All the meat has already been removed prior to delivery at the tannery. The meat is more valuable than the hide, and the workers in the slaughterhouses make sure none of it is wasted. In the tannery the hides are treated with chemicals to remove the hair. If the tannery also prepares raw materials for leather production, the hides will go through further treatments before they are sent to a “splitter.” The splitter cuts through a cross section of the hides. The top portion goes to leather production while the bottom section goes to a gelatin plant. By the time the hides reach the splitter they have been thoroughly processed into a completely flat and clean “sheet” (not more than an inch thick, perhaps even less) of cowhide. At this point it is plainly obvious to any observer that there are absolutely no traces of meat or fat attached to the hide. In some “tanneries” they do not prepare raw materials for leather production. But, still, in those locations the hides are treated with chemicals to remove the hair, which will also remove any other extraneous and unwanted matter should any be present. What remains are tough strips of cowhide that are collected and heaped into a truck that transports them to the gelatin plant.
At the gelatin plant the hides are first treated in a highly caustic chemical solution. The amount of time will vary but the absolute minimum of which I am aware is 6 hours (it's usually a couple of weeks). The environment is quite foul and toxic and nothing that qualifies as a “food,” even if there is somehow anything like that present, will survive the chemical soaking. After the acid treatment the hides are placed in water that is heated to a maximum of 60 degrees Celsius (140 degrees Fahrenheit) which may not even be Yad Soledes Bo. It is in this water that collagen extraction takes place. The greater part of the hides become dissolved in the water and what remains of them is discarded or used in the production of a different product while the liquid solution, which contains the collagen proteins, continues to go through a lengthy process of purification, “ionization” and filtration to remove any unwanted minerals or other unwanted matter of the smallest amount. Eventually the liquid gelatin solution is cooled and turned into “spaghetti-like” noodles which are sent through a very large dehydration oven. When the gelatin comes out of the dehydration oven it has been reduced to a dry, coarse, brittle, flavorless substance which can best be described as a thin piece of plastic. If a spray dryer is used, the liquid solution is immediately turned into a dry powder upon contact with the heat.
It should be mentioned that the Gemorra, Chulin 77a-77b, deals with the case of an extensively cooked hide of neveilla. The Gemorra doesn’t say anything about whether such a hide may be eaten. It only tells us that an extensively cooked hide is included in the laws of Tum’as Ochlin and that it is not included in the laws of Tum’as neveilla. Achronim and Poskim, beginning from at least the 17th century, have told us that the law for eating such a hide will follow its law regarding Tum’as Neveilla. Since the hide is not considered neveilla as far as Tum’ah is concerned it is also not considered neveilla as far as Issur Achilla is concerned. (See Ginas Veradim, Orach Chaim, Klal 2, Siman 15; Zera Avraham, Yoreh Deah, Siman 26; Chelkas Yoav, Yoreh Deah Kamma, Siman 11 [paragraph beginning with “Hayotzay”]). However, the hides used in gelatin production never become “extensively cooked” to the point that they become edible as per the requirements of the Gemorra in Chulin. As mentioned, the hides are placed in water that is heated to a maximum of 60 degrees Celsius (140 degrees Fahrenheit) which may not even be Yad Soledes Bo.
In the case of bovine bones, the process of breaking open the bones, draining the marrow and drying them out takes place in one or two locations even before they are transported to the gelatin plant. When the bones are first delivered to the treatment plant they can still have a significant amount of meat or fat attached, but by the time they leave the treatment plant that has all been removed. Early in the process the broken bones are treated in hot water than can reach 90 degrees Celsius (194 degrees Fahrenheit) which causes the marrow to come out (see further). The bones are sent through a centrifuge and other equipment to separate them from any remaining meat particles which are used in the production of another product. During the drying process the bone pieces are treated with extreme heat that can reach 650 degrees Celsius [around 1,200 degrees Fahrenheit] for approximately 20 minutes and then gradually decreasing heat for another 20 minutes. The bones are then sorted, collected and sent to the gelatin plant.
Once in the plant the bone pieces are treated in a highly caustic chemical solution, usually for a minimum of 20 days, which removes all the unwanted mineral matter and leaves behind only the pure ossein (collagen). Again, the environment is quite foul and toxic, even more so than compared to the hides, and any traces of meat, marrow or flavor, even in the highly unlikely event that any of that somehow survived through the prior treatments, will not survive through the chemical soaking. After this extended treatment in chemicals, the bones have become much softer and the collagen can be easily extracted through immersion in heated water. Like with hides, whatever remains of the bones is discarded or used in the production of another product, and then a similar process of what is described above with the hides takes place.
As far as the possible presence of blood in the hides that would require prior salting, again, prior to production such substances would be rendered utterly pagum by exposure to highly caustic chemicals, during production all foreign matter, to the smallest level, will have been removed through filtration and purification, and the final gelatin product will have become very dry, colorless and flavorless and any blood, even if present (which is not possible), would be in the same condition (see Shevus Ya’akov, chelek 2, #70, regarding the permissibility of “dried blood” and also see Yabia Omer, towards the end of vol. 8, Y.D., #11, section 7). Besides all of this, see Iggros Moshe, Yoreh Deah, vol. 1, Siman 33, who ruled that hides don’t require salting in the first place.
As far as the bones previously being cooked with the meat of neveilla, the extreme heat and lengthy treatment in the caustic chemicals destroys any and all flavors that could possibly be present. See Achiezer, vol. 3, #33, sec. 5 and Yabia Omer, towards the end of vol. 8, Y.D., #11, section 7 and Bais Yosef, Orach Chaim, Siman 447, the section that begins “V’HaRashba Kasav B’Teshuva”. The bone matter itself has NOT become treif as a result of this “cooking” (see Yoreh Deah, Siman 99, Taz, s”k 1, and Shach, s”k 3).
Gelatin produced from pigskins and fish undergo a similar process. During the time they are being treated with caustic chemicals the raw materials have become “Nifsal Meachillas Kelev” (disqualified even for canine consumption) and cannot be ingested. During later stages in production the chemicals are removed and, technically, the gelatin solution can be ingested, but the flavor of the raw materials has already been irretrievably lost. Here also, at the end of production when the gelatin comes out of the dehydration oven it has been turned into a dry, coarse, brittle, flavorless substance which can best be described as a thin piece of plastic (or flavorless, dry powder if it has gone through a spray dryer). Many authorities have ruled that at this point (and perhaps even earlier) the finished product has been utterly disqualified as a foodstuff, meaning, it has become “Nifsal Meachillas Kelev.”