Is gelatin considered to be kosher? I have seen some people say that it is, and others that gelatin has to be kosher-certified.
There is divergence between Orthodox and Conservative Jewish authorities regarding whether or not all gelatin may be regarded as kosher. Orthodox Jewish authorities have ruled that gelatin must be produced from kosher animals. Conservative Jewish authorities, in contrast, have ruled that the process of extracting gelatin, be it from kosher or non-kosher animals, is so rigorous that it renders the gelatin a neutral substance.
Yacov Lipschutz summarizes the Orthodox Jewish position regarding gelatin in the publication Kashruth by ArtScroll:
“Gelatin is produced by extracting collagen, a fibrous animal protein, from beef, calf and pork. After soaking and cooking collagen is filtered, refined and evaporated to obtain the gelatin. Many years ago in the United States, kosher gelatin was produced from kosher-slaughtered and processed calf skins. The supply of this kosher gelatin has long since been exhausted, and the product is no longer produced.
“Since gelatin is highly hydrophilic (able to absorb as much as ten times its weight of water) and forms strong viscous gels, it has many uses in foods and pharmaceuticals.
“In addition to flavored gelatin desserts, gelatin is used in marshmallows, bakery fillings and chiffons, frozen desserts, ice creams, soft cheese and cheese spreads, yogurt, sherberts and water ices, candy gels, and coatings for tablets and capsules. Gelatin beads are also used to encapsulate flavors, colors, and vitamins for use in food products.”
Gelatin that has been extracted from kosher animals, and has been kosher-certified, is certainly available and is used in many commercially-processed foods.
The Conservative Jewish position regarding gelatin is noted in the publication, The Jewish Dietary Laws, which asserts,
“Sometimes the substance is so altered in the process of production that it bears little resemblance to the original. In this case, it does not share the characteristics of its original form. An example of this is gelatin which, though coming from an animal substance, is so altered in the course of production that it cannot be considered in the same category as animal substances.”
Among Messianic books that have addressed the topic of kosher, the 2012 volume Biblically Kosher by Aaron Eby includes a section titled “Hidden Ingredients,” where a number of chemical additives, which may be unkosher, are listed. Gelatin is listed, but the entry only states,
“Gelatin, a well-known gelling agent, comes from animal hides, bones, or hooves, and is found in items such as yogurt, marshmallows, jams, margarine, and ice cream.”
Given the widely Orthodox Jewish orientation for kosher represented by the book Biblically Kosher, it can be assumed that its author would favor the position represented by Lipschutz summarized above. At the same time, though, given the fact that a majority of kosher-friendly people within the Messianic community keep a kosher-style of diet, the Conservative Jewish position of gelatin being a substance so altered by its production, is likely to be adopted by many. Yet as with all chemical additives to processed foods, the buyer needs to be cautious, checking labels, and always being aware of the quality of the item he or she purchases for consumption.
 Yacov Lipschutz, Kashruth: A comprehensive background and reference guide to the principles of Kashruth (Brooklyn: Mesorah Publications, Ltd, 1989), pp 111-112.
 Samuel H. Dresner, The Jewish Dietary Laws: Their Meaning for Our Time (New York: The Rabbinical Assembly of America, 1982), 97.
 Aaron Eby, Biblically Kosher: A Messianic Jewish Perspective on Kashrut (Marshfield, MO: First Fruits of Zion, 2012), pp 124-125.
 Ibid., 125.