Can you use small amounts of fish sauce to cook a meat dish? The amount will be bateil beshishim.
In a case such as yours where there will be less than 1/60 of the fish sauce to the meat, one can approach this two ways. The first is to look at this as we would look at a normal kashrut scenario. From this perspective, the analogy would be a case where one were adding less than 1/60 of milk to meat – the thing itself is permissible, but when you add it to meat and it is more than 1/60th, it becomes forbidden. From this perspective, adding the fish sauce would be a problem of ein mevatelin – you are intentionally adding it in proportions that it will become batel. Although it isn’t issur, you are creating bitul to prevent issur. It is no better than intentionally adding less than 1/60th of milk to meat, which is forbidden.
The other approach is to recognize that this is rooted in a health concern, and not an issur concern, since this emerges from the Gemara (Pesachim 76b) which says “it is forbidden” to eat meat and fish that were cooked together, but specifically identifies the problem as a health issue- it will lead to bad breath and tzara’at. Poskim, as a rule, focus on this “danger” aspect and do not treat it narrowly as a question of issur. This can lead to a more lenient approach or a more strict one, as detailed below. (All these issues are debated, and a good overview can be found in Darkhei Teshuva 116:2).
- How forbidden is it, really?
- Lenient – Not so much – Shulchan Aruckh YD 116:2 does not say forbidden, only that “One must be careful” – צריך ליזהר – “not to eat meat and fish together.” This issue is not mentioned in Rambam, consistent with his general approach to not adopt the health and medicinal issues in the Gemara. Magen Avraham (OH 173:1) similarly writes that-
ואפשר דבזמן הזה אין סכנה כ”כ דחזינן כמה דברים המוזכרים בגמ’ שהם סכנה לרוח רעה ושאר דברים והאידנא אינו מזיק דנשתנו הטבעיות וגם הכל לפי טבע הארצות… וכ”כ הב”ש בשם הרמב”ם.
- Strict – Even more of a problem than issur, since חמירא סכנתא מאיסורא (See Kehal Yehudah, end of YD 88).
- Is there a problem of ein mevatelin ? (See Pitchei Teshuvah YD 116:3 and Darkehi Teshuvah YD 116:20)
- Lenient – No problem – you’re are not nullifying issur, or finding a way to eat something the Torah prohibited. You are just neutralizing dangerous poison (by adding to the amount if it already got mixed up), or adding something in a way that it causes no danger (if you add a tiny amount of fish to a meat stew).
- Strict – Yes, it is a problem – you are playing with something dangerous, and someone could get hurt. Or since Chazal said “assur” might to some degree be defined as issur.
- Is it bateil beshishim? (See Pitchei Teshuvah YD 116:3 and Darkhei Teshuva YD 116:21)
- Lenient – Yes. We should assume that once it can’t be tasted, it can no longer have a deleterious effect. It is possible to argue that even less than 60 would be okay– who knows what the threshold of danger is that Chazal had in mind.
- Strict – No. It is a dangerous ingredient, and could cause harm even with tiny amounts.
In practice, I am not so lenient to adopt Rambam, Magen Avraham, etc. I follow the practice which is the norm in frum communities to not have meat and fish together. That being said, I tend to be lenient about application of this, because of its rootedness is a Talmudic health issue:
- It can be bateil in a mixture, and we do not have to treat it any stricter than a regular issur (which is bateil in 60). I would go further and say that if it already fell into a meat stew, that the stew is mutar bedieved even without 60 on reliance of: (1) those poskim who say it doesn’t apply at all, and (2) it may lose its “harmful” effect even before 60.
- As to ein mevatelin – this is not a problem. Thus, even for those who require 60, it would be permitted to add extra meat and water to a stew that some fish fell into in order to effect bitul.
- As to lekhatchilah adding a tiny bit of fish sauce to a meat dish – from a technical point, I cannot forbid. Although I will say that “religiously” it feels like a little boundary breaking, and could certainly cause others to be dismissive of the problem. So while I wouldn’t say it is marat ayin per se, given that this isn’t about issur, I would be more private about it, certainly if I were a rabbi.