Marshmallows (and other gelatin-based foods)
For over thirty years "Kosher gelatin" has been a substance that the kosher consumer could use as a yardstick to tell if a product was certified by a high or low kosher standard. Up until mid 1993 it was a given that if a product listed "Kosher gelatin" in its ingredients, it meant that the gelatin was definitely derived from non-kosher animals. This was true of all kosher gelatin in the United States, Israel, England, and S. Africa. This was true even when the gelatin was certified kosher by a Rabbi or Rabbinical organization. Those kosher certifiers that adhere to a higher kashrus level, such as the O/U and Star K, categorically rejected the kosher gelatin that was being produced. Instead, these agencies certified various seaweed derivatives, such as isinglass, Irish moss, Spanish moss, agar agar etc. These substances served served as a substitute for real gelatin. Due to the superior gelling qualities of gelatin, a method of producing non-controversial gelatin was sought. In March of 1993, under the supervision of Rabbi Shimon Eider, "kolatin", a gelatin produced from glatt kosher hides, was finally produced. Two main questions are asked in connection with gelatin. One, must it come from a kosher source? The second question is: even when it is derived from glatt kosher hides, why isn't it fleishig? The following is a brief description of the five steps involved in making pareve, kosher gelatin.
1) The hide is chemically decomposed and rendered "Nifsal Meachila". In other words, unfit to eat.
2) Although it was considered unfit to eat, people, nevertheless, use it in food. This is called "Achshevay" and reinstitutes gelatin into a food category.
3) Although gelatin is being used as a food, since it is not eaten by itself, but rather mixed in with many other ingredients, it is not fleishig.
4) Even though gelatin is only one ingredient of many, we must bear in mind that it is a very important ingredient and has the status of a "maamid". This means that it is considered a food stabilizer.
5) In conclusion, Reb Moshe Feinstein Zt"l and Rav Aharon Kotler Zt"l, say that gelatin is "taam kalush" (a weak flavor), and is not fleishig, due to the major change it has undergone. However, it must be derived from kosher sources. If the gelatin was derived from a non-kosher source, such as pig or non-kosher slaughtered hides, although they have been chemically altered, since they originated from a non-kosher source, there is no way to ever render them permissible.