My understanding of the "transference" of non-kosher status to a kosher item.

If I cook a non-kosher piece of chicken in the same pot as a kosher piece of chicken, the kosher piece and the pot are non-kosher. Even after I remove the non-kosher chicken from the pot, it doesn't matter.

But if there's a worm in the lettuce, all I need to do is remove the worm and the lettuce is kosher.

What's the difference with the two? Is it the heating and the transference of "taste"? If so, all chicken tastes alike (pretty much). How would I know the difference between the non-kosher and the kosher chicken? If anything, if I ate the lettuce with the worm, I might taste the worm.


3 Answers 3


The difference between the scenarios is not an abstract difference between nonkosher food and worms, but between cooked and uncooked food and food of the same type and food of different types.

First, taste only transfers if cooking occurs with heat higher than Yad Soledet Bo or one of the substances is "sharp" like an onion (neither worms nor lettuce have "sharp" taste). If the worm and lettuce were cooked together, the lettuce would be forbidden even after the worm was removed. If no cooking occurs, the lettuce is kosher and you only need to get rid of the worm. The cooked chicken has all received nonkosher taste and is forbidden.

The other difference is that the worm and lettuce are different types of food, while the types of chicken are the same type of food.

For a mixture of different substances, two standards decide whether the mixture is forbidden:

  1. Is the taste of the forbidden substance discernable?
  2. Is the proportion of the forbidden substances bigger than 1/60?

Poskim debate whether both criteria must be met to forbid the mixture or only one. If the worm is removed neither criterion is met and the lettuce is kosher.

The Chachamim and Rabbi Yehuda (Menachot 23a) debate the case of similar substances like chicken. Rabbi Yehuda forbids even the smallest amount, while the Chachamim allow the mixture to be eaten if the forbidden food is less than the permitted food (Batel B'rov). If the food is cooked, though, the whole mixture is forbidden according to all opinions because of taste transfer.

Edit. As commenters have noted, the worm could be considered harmful taste, which is permitted even after cooking (although the worm must be removed if it has not completely disintegrated). They also point out that I was acting under the assumption that the worm was greater than 1/60 of the lettuce which is usually incorrect.

  • 3
    According to both the mechaber in Y”D siman 104:3 and the Rama in 107:2 they view bugs such as flies and worms as imparting putrid flavor, and thus would not forbid the lettuce if cooked with the worm (provided that the worm was then removed). Furthermore, I would imagine that the flavor of the worm would anyway be nullified 1/60 relative to the lettuce (unless one cooked one minuscule piece of lettuce).
    – ASL
    Nov 18, 2019 at 14:22
  • 2
    " If the worm and lettuce were cooked together, the lettuce would be forbidden even after the worm was removed" -- this is incorrect, as @ASL mentioned
    – Menachem
    Nov 18, 2019 at 21:53

Chicken transfers a "good taste" (נותן טעם לשבח), whereas insects and other creepy crawlers transfer a "bad taste" (נותן טעם לפגם). The former taste needs to be removed prior to cooking further, while the latter does not.

Before we can talk about nullifying taste in the same or different "Min," it's important to understand what taste is prohibited in the first place. A bad taste (Ta'am Pagum) does not need to be nullified further, whereas good taste does. See Yoreh Deah 100, 103, and 109.

  • Some worms have good tastes.
    – Double AA
    Nov 17, 2019 at 18:08
  • "The former needs to be removed prior to cooking further, while the latter does not." -- this is not true, the worm would also need to be removed. The question only arises if it has melted and cannot be removed. See Y"D 104:3 -- beta.hebrewbooks.org/tursa.aspx?a=yd_x4305
    – Menachem
    Nov 18, 2019 at 22:02
  • Correct, I was referring to the taste, not the item.
    – MDjava
    Nov 19, 2019 at 1:27
  • נותן טעם לפגם מותר רק אם יש ביטול ברוב, זה כתוב בר''ן בע''ז
    – kouty
    Nov 20, 2019 at 15:44
  • I think it's fair to assume that's the case with a work, and, anyway, I wrote see 103, where that Ran is brought lehalacha.
    – MDjava
    Nov 21, 2019 at 1:37

The basic idea is that we consider “טעם כעיקר” is that taste is like the actual item. So when the taste of the forbidden chicken goes into the kosher one, there is effectively forbidden chicken intertwined with it. Whereas by the worm on the lettuce once the worm is removed there is no taste left in the lettuce. I’m sure there’s a better source but I happened to bump into the pri megadim’s intro to bassar vechalav recently so that’s what comes to mind. SH”A Y”D 87

As well these 2 cases aren’t really parallel to each other on 2 sides A)a worm presumably is ״נותן טעם לפגם״ gives bad taste and so wouldn’t make the lettuce forbidden either way even if you cooked them together. Sh”A y”d 103:1 B) 2 pieces of chicken are “מין במינו” “a kind in its own type” as you mention they taste exactly the same as so flavor transfer shouldn’t matter. But there is a rabbinic rule that we require 60x if they were cooked together SH”A Y”D 109:2. Whereas the worm tastes distinctly different (I assume).

Parallel cases would be a kosher piece of chicken with a piece of pork that have touched but not cooked together. In this case all that is required is to clean of the kosher chicken because there is no flavor transfer SH”A Y”D 91:1 .) VS a kosher piece of chicken that was cooked with pork in which case you would need 60x the pork to have it be kosher because the flavor of the pork is now all up in the chicken.

Or Pieces of cold kosher and not kosher chicken mixed with each other, being that it’s מין במינו, יבש ביבש and you can’t tell which piece is which you would need a majority kosher chicken and then you could eat all of it including the not kosher chicken possibly Sh”a 109:1 and the Rema there. VS hot kosher and not kosher chicken mixed with each other in which case you would need 60x kosher chicken.

  • "all chicken tastes alike (pretty much). How would I know the difference between the non-kosher and the kosher chicken"
    – Double AA
    Nov 15, 2019 at 3:46
  • @DoubleAA you wouldn’t. While it being min be’mino would be relevant in some cases. I don’t see why it would be in relation to this question.
    – mroll
    Nov 15, 2019 at 3:48
  • Min bemino means that if the kosher chicken piece is bigger than the Treif piece, the need for 60 is only derabanan. Big nafka mina.
    – Double AA
    Nov 15, 2019 at 3:57
  • @DoubleAA I understand that there are some big differences. But why is that relevant to answering this question?
    – mroll
    Nov 15, 2019 at 3:59
  • You're talking like taste is relevant here but this isn't about taste at all. It's about bittul berov and a gezera min bemino atu min besheino mino on the rotev.
    – Double AA
    Nov 15, 2019 at 4:00

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