Currently taking a biology class in which genetically modified foods were discussed. Some of the plants had DNA from non kosher animals added into the plant genes. How does this impact the kashrus of food which is genetically modified?

This is related to this question about salmon, but perhaps even where salmon could be permitted, other types of food (e.g. birds or other animals where we judge kashrus by tradition about the specific species rather than by observable characteristics such as fins and scales) could not.

  • 2
    Possible duplicate of Is AquAdvantage salmon kosher?
    – Isaac Moses
    Commented Nov 24, 2015 at 0:48
  • @isaacmoses I think not a duplicate because that question asks specifically about fish.
    – Daniel
    Commented Nov 24, 2015 at 12:36
  • @Daniel, why would food that's not fish be different from fish with respect to this question? Please edit this question to specify such a distinction if you see one.
    – Isaac Moses
    Commented Nov 24, 2015 at 14:38
  • @IsaacMoses Does the edit clarify what I think is different? Dude, is my edit to your question acceptable to you?
    – Daniel
    Commented Nov 24, 2015 at 14:45
  • @Daniel, yes; thanks. I've retracted my close vote. I dejargonified your addition a little.
    – Isaac Moses
    Commented Nov 24, 2015 at 14:48

2 Answers 2


Rav Heinemann said that if the DNA of something does not affect the taste (or smell, sound, appearance) of it, then the fact that the DNA is present does not make a difference. He explained this as a function of the same principle that allows us to eat bacteria - halacha deals with what you can detect (even though we could use a microscope to see it. The Torah deals with the realm of our natural experience). If the tomato has no characteristics that observably resemble the pig that the DNA came from, then it is OK. However, if it does have observable features that liken it to its DNA source, it is a problem (an oinking tomato would not be Kosher).

Additionally, a friend pointed out that most genetic engineering and modification is not actually done with DNA directly from the organism that provided the DNA, but rather they synthetically copy the DNA (is is a much more efficient way to produce a lot of it) and then inject that into the specimen. Rav Heinemann said that if that is the case, then it isn't considered as being non-Kosher DNA in the first place - it is a synthetic replica, but not the actual non-Kosher species. Therefore, even if it gave taste, it wouldn't matter.


This is basically the same type of question as Is AquAdvantage salmon kosher?. Just as the fish use the simanim of fish and the DNA does not effect the results, this question also would have the DNA not change a plant into an animal. Since it is about plants and not animals the question may be considered different even though the answer is the same.

  • That answer may work for fish but what about birds/other animals where Ashkenazim don't generally go by simanim but rather by mesorah?
    – Daniel
    Commented Nov 24, 2015 at 12:35
  • I am not sure. I do not know if the change would be considered significant enough or not. I suspect that if the new bird could breed with the old that it might be considered the same, bu I am not sure. In any case, I do not think that DNA analysis would be as significant as visible factors. However, this is speculation only. Commented Nov 24, 2015 at 13:26
  • @Daniel Mimanafshach: if the derivative is the same species, it's kosher; if it's a different species, it's not one of the species of bird listed in the Torah as non-kosher.
    – Double AA
    Commented Nov 24, 2015 at 14:48
  • @DoubleAA Ok so maybe deoraita it's no problem. But we have a current practice of only eating birds that we have a mesorah for being kosher. Perhaps your logic would apply to show that such a practice is meaningless in this case, but I don't know that it wouldn't be enforced anyway. In other words, if it's a new species there's no mesorah for eating it.
    – Daniel
    Commented Nov 24, 2015 at 14:53

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