2-5771 Mitzvah N-91
Negative Mitzvah 91– This is a negative commandment: do not cook meat in milk.
Hafetz Hayim – As Scripture says: “You shall not boil a kid in its mother’s milk.” (Exodus. 23:19); If someone cooks meat in milk using an olive’s amount of the both, he should receive whiplashes, even if he does not eat it. It is forbidden to have any benefit from it, and it requires burial, and it is even forbidden to have any benefit from its ash if he burns it. This applies, however, specifically to meat of a kosher animal in milk from a kosher animal, even if it was n’velah(see 90 & 86); then whiplashes should be suffered for cooking it. But if it was meat of a kosher animal in the milk of a non-kosher animal or meat from a non-kosher animal in the milk of a kosher one, or it was the meat of a kosher untamed animal or fowl in milk, cooking it and having benefit from it are permitted , but not eating it.
This applies everywhere and always, for both men and women.
This is all pretty straight forward except for one thing. The assumption in all of this is that the punishments for cooking meat in milk are only valid if the cooking was done with intention. None of these punishments applies if the cooking was done in error or by mistake. While there is no punishment for the person caught cooking meat and milk together by mistake still, the utensils used do become trayf and need to be re-kashered in most instances. You can see this in the halacha above when you note that there needs to be at least an olive’s amount (about 45 cubic cm.) of one or both the meat and the milk in order to merit the punishment. Less than that was considered an error. Later the rule of 1/60th came into play that if the amount of milk in meat or meat in milk was less than 1/60th of the volume of the other, then it was considered as if nothing had happened.
In general, if something is forbidden, then any use of it at all is forbidden; in our case, even gaining any benefit from anything that results from the cooking: the dirty pot could not be used to feed animals, the ashes could not be spread in the garden and you certainly can’t sell the trayf food to a non-Jew and pocket the money (or even get a tax deduction). In cases where there may be doubt about if the animal was cooked in its mother’s milk, that is an untamed kosher animal (where we don’t usually get milk from them) or fowl ( who have no milk)then we can benefit from the cooking; that is we can sell it to non-Jews even if we can’t eat it. There was a time when fowl could be eaten with milk but the Talmud expressly says that since there could be confusion between the two kinds of meat, from mammal and from fowl, then we don’t allow anyone to eat either meat with milk.
I should note here that, in cases of error, the dishes used are not kosher until they are re-kashered. There are some exceptions. If both the milk and the meat are mixed cold, then neither can be eaten and the plate that held the mixture needs only to be washed and not used for the rest of the day. If hot meat was placed on a cold dairy plate or hot milk placed in a cold meat bowl, the food may not be eaten but the plate or bowl needs only to be washed thoroughly. If cold meat is placed on a hot plate, or milk is put into a hot bowl, then cooking can take place and a full re-kashering, if possible, needs to be done. This means either immersion in boiling water or passing through flame. Ceramic dishes cannot be kashered and can no longer be used.
There is a common misconception that if you bury the utensil in a flowerpot or in the back yard overnight, this will re-kasher the utensil. This is just not true. If it needs to be re-kashered, then it must be heated beyond the temperature it was at when the violation occurred either through immersion or passing through a flame. If this is not possible, then the item can’t be re-kashered. I suggest, however, before any item is thrown away, a Rabbi should be consulted; since there are often many exceptions and exemptions. While our neighbors may be very kosher in their home and we may have many friends who are strict in their observance of Kashrut, it is best to consult a Rabbi with any questions since there are many people who rely on “stories” rather than law in dealing with violations of Kashrut. When it comes to the rules of milk and meat, it is always best to verify what we are doing with a reliable authority.