Judaism: Koshering the Kitchen for Passover
Executive Summary: Cleaning the kitchen for Pesach (Passover) should be done more carefully than cleaning the house, to ensure that not even a small crumb of chametz (leavened food) remains * Solutions for baking on Pesach, seeing as oven baking trays used for chametz cannot be koshered * When koshering stovetop grates, we are more concerned about the prohibition of chametz than the prohibition of mixing meat and milk * It is forbidden to eat food that fell under the stovetop grates all year round * How to kosher the sink and countertops, and is it necessary to cover a marble countertop with aluminum foil * How to kosher a microwave and dishwasher * What to do with modern tables, where pouring boiling water on them ruins them.
Cleaning the House
There is a significant difference between cleaning the house for Pesach, and cleaning the kitchen. When cleaning the house, the goal is that a crumb of chametz the size of kezayit (an olive) should not remain. But when cleaning the kitchen and its utensils, the goal is that no chametz whatsoever (kol she’hu) remain, lest it gets mixed in food for Pesach. And as is well-known, chametz on Pesach is forbidden even b’kol she’hu. And when it comes to cooking utensils, even the taste of chametz absorbed in them should not remain, lest the taste of chametz, kol she’hu, get mixed in Pesach foods while cooking or baking.
There are some people who do not realize this fundamental difference and clean their house very carefully, but afterwards, slack-off in cleaning the kitchen.
Koshering a Baking Oven
To kosher an oven, clean it thoroughly and run it at its highest setting for half an hour.
It is difficult to kosher baking trays. Because they absorb through fire, they require heavy libun (heating a vessel by fire to the point that absorbed taste is incinerated), but since heavy libun will cause them serious damage, they may not be koshered. One must therefore buy special baking trays for Pesach, while the chametz trays must be cleaned and put away like all other chametz utensils. If one does not have Pesach trays, he may use disposable trays.
With regard to baking trays, however, we are stringent and require heavy libun. However, if one conducts light libun on a tray, he may place a disposable tray inside of the multi-use tray, and certainly atop the racks. It is best to cover the racks with aluminum foil, so that if something spills onto them it will not connect the Pesach tray to the insufficiently koshered racks (see Peninei Halakha: Pesach 11:4).
Grates and Burners
Throughout the year, people usually use the same stove top grates for both meat and milk, because even if some meat or dairy food spills onto them, the flame incinerates and befouls whatever has spilled. However, people customarily perform light libun on such grates for Pesach, because of the seriousness of the chametz prohibition (Rema 451:4; MB ad loc. 34). Alternatively, one may wrap thick aluminum foil around the bars on which pots sit, so that there is a barrier between the Pesach pots and the parts of the grates that came into contact with chametz. Be-di’avad (a level of performance that ex post facto satisfies an obligation in a less-than-ideal manner), the food remains kosher even if cooked on grates that did not undergo libun.
The areas of the grates that do not come into contact with the pots, the enamel cook top beneath the grates, and the burners must be cleaned well of all residual food. Since none of these parts come into contact with the pots, they need not undergo libun or be covered with foil. Generally, people turn on all the flames for half an hour.
The Law of Food that has Fallen under the Grates
It is also important to know that throughout the year one should be stringent and refrain from eating food that has fallen onto the enamel cook top under the grates, because meat and dairy foods spill there, and the enamel becomes not kosher. If one knows that the enamel has been cleaned thoroughly and that no meat and dairy foods have spilled on it in the past twenty-four hours, one may eat what falls there.
But when these two conditions have not been met, one should be stringent and refrain from eating whatever comes into contact with this enamel, because it might have absorbed the taste of meat and milk. If a thick piece of food falls there, one may cut off the side that has come into contact with the enamel and eat the rest.
Electric ranges: Clean thoroughly and run on the highest setting for half an hour.
Ceramic burners: These look like smooth and unbroken glass surfaces on which pots are placed directly. They are koshered for Passover by cleaning and then heating on the highest setting for half an hour. One should wait twenty-four hours between the last chametz cooking and beginning to cook for Pesach (this heating is considered light libun, which is sufficient for it according to the vast majority of poskim).
Sinks and Counter-tops
There are two accepted practices for koshering them: Those who are lenient clean them well and then pour boiling water all over them. Before pouring boiling water on a sink or counter-top, it must be dried well, so that the boiling water touches it directly and is not cooled by any cold water on its surface. For this reason, one must first pour the boiling water on the sink and then on the counter-top, starting with the areas closest to the sink and moving further away. To do so, one can also use a steam machine, whose steam heat reaches one hundred degrees (and has the status of pouring boiling water from a kli rishon, namely the vessel in which food was cooked).
Those who are stringent, in addition to pouring boiling water on the sink, put a plastic insert in it or line it with thick aluminum foil.
If the marble counter-top is fragile, and as a result, one is careful not to place boiling pots directly on it – even those who are stringent can suffice by pouring boiling water on it, without covering it with an oilcloth or aluminum foil (see, Peninei Halakha: Pesach 11: 1-2).
Warming Tray (Shabbat - Sabbath - Plata)
It should be thoroughly cleaned, and heated on the highest heat for two hours, and covered with aluminum foil.
A blekh (a metal sheet that is placed atop a gas range on Shabbat) can be koshered in one of two ways: 1) clean it, and perform light libun. 2) Clean it, heat it for two hours like on Shabbat, and in addition, cover it with aluminum foil (Peninei Halakha 11:5).
The common practice is to kosher a microwave oven in four steps: 1) cleaning it thoroughly of any residual food resulting from spillage or vaporization; 2) waiting twenty-four hours so that the absorbed taste becomes foul; 3) heating a container of water in it for three minutes (since microwave ovens absorb chametz via vapor that rises from food as it is heated); 4) placing something as a barrier between the rotating plate and the food that will be heated in the microwave, because chametz may have spilled onto the rotating plate, and when using it on Pesach, place the food in a plastic container or a thick, perforated carton, separating between the rotating plate and the foods being heated on Pesach. If possible, it is good to change the rotating plate for Pesach (Peninei Halakha: Pesach 11:6).
The filter, where residual food often gets stuck, must be cleaned thoroughly. Then the dishwasher should be run at its hottest setting, so that any absorbed chametz is released, ke-bole’o kakh polto (taste is released from a vessel in the same manner that it was absorbed). Regarding the racks, le-khathila (a level of performance that satisfies an obligation in an ideal manner) they should undergo hagala (immersion in boiling water) or irui (“pouring”; one of the ways taste is transferred; an intermediate phase between kli rishon and kli sheni) with boiling water or be replaced.
If it is difficult to kosher them through hagala or to replace them, one may perform hagala by running them through the dishwasher’s longest and hottest setting. Regarding the racks, le-khathila they should undergo hagala or irui with boiling water or be replaced. If it is difficult to kosher them through hagala or to replace them, one may perform hagala by running them through the dishwasher’s longest and hottest setting.
In any event, one must wait twenty-four hours after the last load of chametz utensils before using the machine with Pesach utensils.
Some take a stringent approach to dishwashers and consider them to have the status of a kli rishon on a flame. This means that to kosher a dishwasher one must put a white-hot piece of metal in it in order to boil the water. However, those who follow the lenient approach have authorities who do so and on whom to rely (Peninei Halakha: Pesach 11:7).
The Dining Table
In the past, people would kosher their tables by pouring boiling water over them, and some took the stringent approach of pouring boiling water onto a white-hot stone on the table, so that the koshering would be at the level of kli rishon. However, today’s tables are more delicate and fragile, and would be damaged, warped, or defaced by boiling hot water.
Therefore, the mainstream approach is to clean the table well and affix nylon or paper to it, creating a set barrier between the table and Pesach utensils and foods. In addition, a tablecloth should be spread over the nylon or paper, and it is a good idea to avoid placing boiling hot pots directly on the table (Peninei Halakha: Pesach 11:8).
Because they are used with cold food, the only concern is that some chametz crumbs might remain there. Therefore, cleaning them is what koshers them. In hard to reach places where chametz crumbs may have gotten stuck, one must pour soapy water or some other substance that will befoul the crumbs and render them unfit for animal consumption.
When kitchen cupboards were made of natural wood, they often had cracks that were difficult to clean completely from chametz that got stuck there. Akharonim (halakhic arbiters from Rabbi Joseph Karo onward are called Akharonim) therefore ruled that the shelves should be covered with paper or cloth (MB 451:115). However, there is no concern that chametz remained in smooth shelves like those used today. Therefore, once they have been cleaned properly, they need not be covered with paper or cloth. Nevertheless, many people cover the shelves with paper (Peninei Halakha: Pesach 11:9).
Plastic Baby Bottles
It is better to replace them, but when necessary, one may clean them and perform hagala (immersing in boiling water).
Electric water heaters
Electric water heaters and Shabbat water heaters (that are placed on the plata) must undergo hagala,because chametz crumbs may have fallen into them, causing their taste to be absorbed. Hagala in this case means filling the device to the top with water, boiling it, and then pouring it out through the opening generally used to dispense the water. Before hagala, it is good to clean out the stone deposits that accumulated inside. If one places challah loaves on the lid of the urn to warm them before the Shabbat meal, hagala should be performed on the kettle and its lid.
After cleaning it properly, hagala should be performed on it. If this is difficult, pouring boiling water into it and around its opening is sufficient.
False teeth should be cleaned thoroughly before the onset of the chametz prohibition. They need not undergo hagala, because people do not normally put boiling foods or liquids in their mouths; just as they are used for both meat and dairy when cleaned in between, so can they be used on Pesach. (Some believe that due to the gravity of the chametz prohibition, they must be koshered in a kli rishon or kli sheni.
The status of braces is similar to that of one’s teeth; just as one thoroughly brushes his teeth before Pesach, so should he brush around the braces.
Selling One’s House does not Exempt Him from Bedikat Chametz
There are some people who go away for all of Pesach, and wish to sell or rent their house to a non-Jew in order to be exempt from bedikat chametz (checking for chametz). However, according to halakha, this does not exempt them from bedika (Peninei Halakha: Pesach 4:11). Therefore, they must clean the house normally, as they do every week. And on the last night they spend in the house, they must check the house for chametz – namely, check to make sure that no crumb larger than a kazayit remains.
Such a bedika in a normal-sized house after a normal cleaning should take approximately fifteen minutes. In a house with children, since they sometimes hide chametz in various places, the bedika should take more time. But if in such a house all the drawers and shelves were previously cleaned, the bedika should take about fifteen minutes, as well.
They must also normally clean the kitchen and its utensils of all substantial chametz , so they can use them after Pesach. However, they do not have to kosher the kitchen utensils that have absorbed chametz, since they do not plan on using them on Pesach.
This article appears in the ‘Besheva’ newspaper, and was translated from Hebrew.