One of the main trademarks of a Torah observant home is the kosher kitchen. Dual sets of dishes, cutlery, and cooking utensils are standard features of any home where adherence to the Shulchan Aruch is the way of life. And, while every effort is made to keep the milchigs and fleishigs (dairy and meat) separate, inevitably mistakes occur resulting in uncertainty as to the status of the food and utensils involved. Although no printed words can replace the time-cherished practice of consulting a Rav to resolve any sha'aloh that arises - certainly not a brief Halacha Encounters - nonetheless I would like to present some principles that can be useful in determining when a sha'aloh must be asked.

At the outset, let us understand why it is necessary to have separate utensils for milchigs and fleishigs. Assuming the fork I am using is clean of any meat residue why can't I use it to eat my cheese lasagna? To answer this we must introduce the concept of ta'am, or absorbed flavor. We are taught that when a utensil comes in contact with hot food, the walls of the utensil absorb and store some of the ta'am of that food. Subsequently, when the same utensil touches other hot food, some of that stored ta'am is drawn out into the second food. So if, for example, I were to use a fork to eat a hot piece of chicken or meat, if that same fork would then be used for hot milchig food, the milchigs would draw out some of the meat flavor which was contained in the fork, while at the same time the fork would absorb some ta'am from the milchig food.  As a result, both the food and the fork would be rendered treif since both would now contain a mixture of milk and meat. This same concept can be applied to dishes and pots as well.

However, not in all cases would the infusion of milchig ta'am into fleishig food (or vice-versa) render the food treif. There are two major exceptions which are very relevant to our discussion.

The first exception involves the concept of bitul b'shishim. In most cases, if the volume of the food item which is receiving the foreign ta'am is sixty times greater than the volume of the ta'am, the entering ta'am will be considered batail, or, nullified, and have no effect on the status of the food.

The second exception is with regard to ta'am pogum, or, foul flavor. Only ta'am which enhances the quality of the food has the ability to render the food treif. Ta'am which is detrimental to the taste of the food becomes batail upon entry even where there is not a sixty to one ratio. Furthermore, any ta'am which remains absorbed in the walls of a utensil for twenty four hours automatically reverts to the status of ta'am pogum. Hence, although a utensil of one type (milchig or fleishig) may never be used for hot food of the other type, not in all cases will using it for the wrong type render the food treif. If, for example, a fleishig pot did not come in contact with hot meat within the twenty-four hours prior to mistakenly using it to heat up milk, the milk will remain kosher and fit for consumption. The pot, on the other hand, will now be considered treif and require kashering.  For although the pot had no effect on the milk, the milk which got absorbed in the pot walls surely affects its status.

Bearing these concepts in mind, let us examine two cases which tend to occur not infrequently. CASE1: A milchig spoon was used to stir hot chicken soup. What is the status of the soup, the spoon, and the pot? (Note: If the soup was not in the original pot but had been transferred to a bowl or other container, the nature of the sha'aloh is altogether different. Just as with regard to hilchos Shabbos we draw distinctions between a kli rishon and a kli sheini, the same holds true with regard to the laws of Kashrus. The Rav who is consulted must be provided with the precise details of the case.)

The first factor to consider is how hot the soup was when this incident occurred. Only food which is at a heat of "yad soledes bo" (lit. hot enough o cause one's hand to recoil) will cause the transfer of ta'amim which we described above. The precise temperature of yad doledes bo is a subject of much discussion amongst Poskim. According to HaGaon Rav Moshe Feinstein zt"l (Igros Moshe O.C. 4:74) a temperature lower than 110º F is certainly not yad soledes bo. If one is certain that the soup was not yad soledes bo when the spoon was inserted, no kashrus problem exists. Simply wash off the spoon (don't use hot water so as not to implant any ta'am from the soup residue into the spoon) and replace it with the milchig silverware. The chicken soup may be eaten and the pot is still kosher.

If the soup was yad soledes bo when it was stirred with the milchig spoon, the spoon is now treif and should not be used again until it is kashered through hagolah (purging). Regarding the soup and the pot, one must first determine if the spoon was a ben-yomo from milchigs at the time of the stirring. (Ben-yomo refers to a utensil which was used for hot food within the preceding twenty-four hours, as explained above.) If the spoon was not a ben-yomo, the soup and pot are kosher. If the spoon was a ben-yomo the soup will be kosher only if the volume of the soup was at least sixty times greater than the volume of the milk absorbed in the spoon. Since it is generally impossible to know precisely how much milk is absorbed in the soup, the Shulchan Aruch rules that the soup must be at least sixty times greater than the section of the spoon which was actually placed in the soup. (See Yoreh Deah 94:1 See also Pischei T'shuva s"k 1 and Aruch Hashulchan that some Poskim hold any part of the spoon which entered beneath the rim of the pot, even if it didn't come in direct contact with the contents, is part of the equation.) When the requisite "sixty" is present, both the soup and pot are kosher. Without sixty, they are both rendered non-Kosher; the soup must be discarded and the pot can be kashered through hagolah.

CASE 2: A milchig spoon was used to stir a hot pareve soup which was cooking in a fleishig pot at a temperature of yad soledes bo. The halacha in this case - for Ashkenazic Jewry - is as follows. If both the pot and spoon were ben-yomo of their respective food type, everything is considered treif. The soup must be discarded and the utensils require kashering. If the pot alone was a ben-yomo, the soup is kosher, but if possible should not be mixed with anything but other pareve food. If this is very difficult, or not feasible (e.g. instead of soup, say it was a sauce which is used exclusively as a topping for meat) one could mix it with fleishigs, but certainly never with milchigs. If the spoon was a ben-yomo and the pot wasn't the reverse would be true (i.e. the soup could be mixed with the milchigs if necessary, but not with fleishigs). In both of these last two cases the minhag is to kasher the utensil which was not ben-yomo. If, however, in the case of the ben-yomo spoon, the volume of the soup was sixty times greater than the part of the spoon which was inserted, many Poskim hold the pot need not be kashered and the soup may be mixed with fleishigs.

Even when everything runs smoothly and no mix-ups occur, there are a few rules of the kitchen which warrant review. (Please note that there are significant differences between Ashkenazic and Sefardic practices in these matters. This discussion follows Ashkenazic laws and customs.)

One who eats pareve food which was cooked in a fleishig pot does not have to wait six hours before eating milchigs. Rather, he may eat milchigs immediately afterwards. Additionally, he may even use milchig dishes and silverware to eat this pareve food. However, to eat this food together with actual milchigs, or to mix it with milchig food, is not permissible. Even so, if this food is accidentally mixed with milchigs it remains kosher and may be eaten.

These rules apply to pareve food cooked in a milchig ben-yomo pot. With regard to pareve food cooked in a non-ben-yomo pot, there is one difference. Initially, one should not use any fleishig pot to cook food which he intends to eat with milchigs. Nonetheless if the food was cooked in a non-ben-yomo without any such intention, one would be permitted as an afterthought to eat it with or mix it with milchigs. (This is in contrast to food cooked in a ben-yomo fleishig pot, where the halacha is one may not eat it or mix it with milchigs even as an afterthought. Only if it accidentally came in contact with milchigs did we explain above that it may still be eaten.)

All of the above laws may be reversed and applied to pareve food cooked in a milchig pot, with regard to eating it with fleishigs.

Regarding sharp-tasting foods (e.g. onions), there are certain differences in the halacha. Foods of this type if cooked in a fleishig utensil should not be mixed with milchigs (and vice versa) even if the utensil was not a ben-yomo. However there are a number of factors to consider whenever a sha'aloh of this nature arises, and a Rav should be consulted before eating - or discarding - the food in question.

Lastly, it should be noted that even fish may be cooked in a fleishig pot, even if the pot is a ben-yomo from fleishigs.Not withstanding the fact that certain G-d fearing individuals have the minhag of designating a separate pot for fish, and that the Tur (Y.D. 116) makes mention of such a practice, the Shulchan Aruch omits it and the accepted halacha is that it is not necessary. A number of Poskim state explicitly that we are only concerned with a mixture of actual fish and meat, or with the ta'am of one entering the other directly (e.g. by cooking them together in one pot), but not with ta'am which is transmitted through the walls of a pot. (See Taz Y.D. 95:3;Pri Megadim Sifsei Daas Y.D. 108:18, Hagohos Rabbi Akiva Eiger Y.D. 116 to Shach s"k 1.).