The following question was sent to me:
Dear Rav Abadi,
Thank you for this, I have read the Taaruvot sheet which was very helpful.
I have discussed this with a few people, and we are still wondering as follows: Yes everything is about taste, however I might not know that I am tasting a new kosher ingredient; in other words, how can I decide whether or not there is taste? If a product has been cooked on a line that has had issur earlier that day, yes it was washed etc, but how can I know that I am not tasting issur in my product- I don’t know what issuer tastes like. It could be any number of flavour that I just don’t know what they are and what they taste like.
Additionally, I contacted a prominent Kashrut authority in the US with the same question (why can’t we rely on ingredients) and they told me (amongst other things) that the main concerns are this:
- Davar charif – which include vinegar, mustard, barbecue sauce, soy sauce, salsa, anything fermented, salty, sour, or spicy. These items are forbidden if made in Kettles that also cooked anything non-kosher, and even if the kettles are aino ben yomo (not ben used in 24 hours). Any product that contains any of these ingredients could also be problematic.
- Flavors – are often a davar charif. Even if the orange candy is not charif, but the concentrated orange flavor is a davar charif, and since the orange flavor comes from a flavor company which also make non-kosher flavors, unless the machines are kashered that flavor is not kosher… “ (end of quote)
What do you think about this. I really appreciate your time in answering these questions.
Thank you for reading and for taking the time to think through the material carefully. I appreciate the seriousness of your questions.
Let me clarify something fundamental.
Hilchot Ta’aruvot are not built on speculation. They are built on ta’am – taste. This is explicit throughout Shulchan Aruch (see YD 98, 103, 96). If prohibited taste is present, the food is forbidden. If prohibited taste is absent, the food is permitted. That is the system.
You ask: “How do I know if I am tasting issur if I don’t know what it tastes like?”
Halacha does not require expertise in exotic flavor identification. If you taste meat in your tuna, you know. If you taste dairy in your steak, you know. If there is a noticeable foreign flavor, it is detectable. If there is no detectable flavor, then halacha defines that as no ta’am.
The reason this feels abstract is precisely because, in modern production, cross-flavor contamination simply does not occur in a meaningful way. Restaurants and factories cannot function if their products taste like something else. Health regulations, allergen laws, and basic business reality make that impossible. But more importantly — halacha itself says absence of taste means absence of prohibition.
Regarding the points you quoted:
1. Davar Charif – Shulchan Aruch YD 96 makes clear that even in the classic case of tznon cut with a meat knife, the determining factor is taste. If no meat flavor is present, it is permitted. Davar charif is not a mystical rule; it is a mechanism for potentially drawing out taste. Without taste, there is no issue.
2. Flavors and shared equipment – Again, everything returns to ta’am. If a flavor company produces both kosher and non-kosher products, the question is whether prohibited taste is present in the final product. If not, there is no prohibition. The halacha does not create issur based on theoretical microscopic residue without flavor.
Halacha does not operate on the assumption that invisible, undetectable, non-functional traces create prohibition. That is simply not the system described in Shulchan Aruch.
I am also not interested in being positioned against other rabbis. My approach is not polemical. It is textual. Anyone is welcome to open Yoreh De’ah inside and learn the sugyot directly.
If you reread the Ta’aruvot material from kashrut.org; especially the sections on kefela, batel be’shishim, noten ta’am lifgam, Davar Charif, and the difference between food status and utensil status … you will see that these concerns are already addressed within the halachic framework itself.
Going forward, I’d appreciate if you post your questions and concerns on the Q & A Forum at kashrut.org, so others can learn from these discussions. Of course anything personal or private can still be by email.
With respect,
Aaron Abadi