Spicy foods - Davar Charif

I just realized that I cut onions with a meaty knife and mixed them into a milky dish. What do I do? May I eat the food, or does it have to be thrown away? And what about the milky pot that I used?

Thank you for your question.

Davar Charif – Spicy foods:

There are a few aspects that have to be analyzed before we can give a definitive answer on whether the food is permitted or needs to be thrown away.

An onion is considered a davar charif, a spicy food. In halacha, a food that is considered a davar charif has specific stringencies that are not found in normal foods, and there are three main specific halachot

1. Generally, we say that taste from another food gets absorbed into a food only if it is cooked together since, through the process of cooking, the taste gets extracted from the food and enters the second food. However, when it comes to a davar charif, the taste gets absorbed into another food even if it is not cooked together. For example, if someone uses a meaty knife to cut an onion, then we say that the taste from the meaty knife gets absorbed into the pareve onion, and now the onion would be considered meaty.
There is a machlokes ha’poskim as to how much of the meaty taste from the knife gets absorbed into the onion:
According to the Mechaber, and this is the Sephardi custom, the taste gets absorbed 2.4 cm from both sides of the cut onion.
According to the Ashkenazi custom, the whole onion is considered meaty.

2. Generally, we say that if the knife is used twenty-four hours after the original meaty taste was absorbed, then we say the taste that gets passed on to the other food, cannot prohibit it, that is only for normal foods.
However, with a davar charif, even if it was originally used for meat a long time ago, nevertheless, when it is used now to cut a davar charif, the taste becomes like fresh, and the taste absorbed in the onion is considered as if it was a taste that was used within twenty-four hours. (The Kaf Hachaim, Siman 96, seif 11, and many poskim write that even the Mechaber agrees with this opinion).

3. There is generally a certain leniency when it comes to the halacha of 'second taste,' which in Hebrew is called Nat Bar Nat. However with regard to davar charif, even though the taste of the meat in the knife now gets extracted into the onion, we do not say that this is like Nat Bar Nat, but rather it is considered as if the original taste of the meat entered the onion.

What makes a knife “Meaty”?

All the halachot that we mentioned above, of course, only apply if a meaty knife was used. So, do we know what makes a knife Halchikly “meaty”?

To consider a knife as “meaty”, it must have been used to either cut hot meat that was “yad soledet bo” in a kli rishon (the dish it was cooked in), or was cutting cold meat and a davar charif, like an onion simultaneously.

Only in these two instances do we give the knife a status as “meaty”, and then all the above halachot apply

Sometimes a person does not know or even is not sure whether this particular knife was used as described above. So, in this instance, we do not consider it as “meaty”, since there is a chance that it was not used as described above, it is not considered meaty.

Be’dieved:

In a case like you mentioned, where the milky food was already cooked, and then you relised that the onion used, was cut using a meaty knife, the halacha is as follows

1. First, check if the knife is really considered halachicly “meaty” as explained above.

2. If it was a meaty knife, then according to all customs, if there is shishim against either the area of the knife that was used to cut the onion, or if there is shishim against 2 – 2.4 cm from both sides of the onion that was cut (whichever has the least amount), then the food and the pot are kosher. Of course, if one can detect the meaty onion, then it would need to be removed.

3. If there was no shishim against either the knife or the 2 – 2.4 cm amount of onion, then the food is prohibited, and the pot needs to be kashered.

wi Wishing you all the best.

Shulchan Aruch YD siman 96 

Pesakim ve'tshuvot page 81