Utensils are koshered in the manner in which they were used with forbidden food or with chametz * The fundamental rule is “ke-bolo kakh polto” (“as it absorbs, so it expels”) * In cleaning the house, the goal is that no chametz of the size of a kezayit (olive’s bulk) remains * In the kitchen and its utensils, the goal is that not even the slightest amount of chametz remains * Countertops and sinks are cleaned thoroughly, and afterward boiling water is poured over them * Due to the severity of chametz, it is customary to kosher the gas grates with light libun (heating) * A refrigerator is used with cold, therefore its koshering is by cleaning
The Principle of Koshering – “Ke-bolo Kakh Polto”
The fundamental rule in the laws of koshering utensils from forbidden to permitted use, or from chametz for Passover, is “ke-bolo kakh polto.” That is, one must kosher the utensil in the way it was used with forbidden food or chametz.
There are three forms of use:
1) With fire (direct heat), and its koshering is by libun chamur (intense heating).
2) With hot liquids – and its koshering is by hagalah (immersion in boiling water), and this too has levels: kli rishon on the fire, kli rishon not on the fire, irui from a kli rishon, and kli sheni. And “as it absorbs, so it expels.”
3) With non-hot liquids, and to kosher it, cleaning with cold water suffices.
A Utensil Used at Two Levels
A spoon that sometimes absorbed chametz in a kli rishon on the fire, and sometimes in a kli sheni, is koshered according to its more severe use—namely, in boiling water on the fire. However, when this is difficult or may cause damage, one follows the majority of its use.
For example, a fork that is generally used in a kli rishon or kli sheni, whose koshering is in boiling water, but is occasionally inserted into baked goods in an oven, where absorption is by fire—since libun may damage the fork, one follows the primary use and kosher it with boiling water (Peninei Halakha, Pesach 10:7).
Cleaning the House
There is a great difference between cleaning the house for Passover and cleaning the kitchen. In cleaning the house, the goal is that no chametz the size of a kezayit remains, so as not to violate “bal yera’eh” and “bal yimatzeh.” In contrast, in cleaning the kitchen and its utensils, the goal is that not even the smallest amount of chametz remains, lest it mix into Passover food, since chametz on Passover is forbidden even in the smallest amount. When it comes to cooking utensils, there must also not remain even a trace of chametz taste stuck to or absorbed in them.
Countertops and Sink
They are cleaned thoroughly, and afterward boiling water is poured over them. It is convenient to do this with a kettle. One should try to ensure that the sink and countertop are dry, because if they are wet, the water on them will slightly cool the boiling water.
Therefore, it is good to first pour boiling water on the sink, then on its sides, and afterward on the countertop near the sink, and then on the more distant areas, so that the water flows into the sink and not onto areas that have not yet been koshered.
Instead of pouring, one may cover the countertop with plastic or aluminum foil, and place a plastic basin or thick foil in the sink. Those who are meticulous both clean and pour boiling water, and in addition cover the countertop and sink (Peninei Halakha, Pesach 11:1). A sensitive countertop, on which one never places a boiling pot, may initially be koshered by cleaning and pouring alone, and even the meticulous do not need to cover it.
Koshering the Gas Stove
All year we use the same grates for meat and dairy pots, because even if some food spills over, we assume the fire burns and spoils what is spilled. However, before Passover, due to the severity of chametz, it is customary to kosher the grates with light libun.
In pressing circumstances, one may suffice with cleaning the grates in place and lighting all the burners on high for about a quarter of an hour. Those who are meticulous, in addition to the light libun, cover the metal supports on which the pots stand with aluminum foil.
After the fact, if one did not perform libun on the grates and cooked on them during Passover, the food is kosher (as is the practice all year regarding meat and dairy). The other metal parts that do not touch the pots, as well as the enamel surface beneath the grates and the burner heads, are cleaned thoroughly (Peninei Halakha, Pesach 11:2).
Electric and Ceramic Stovetops
Electric stovetops: Clean thoroughly and heat on the highest setting for about a quarter of an hour.
Ceramic stovetops: The surface is made of opaque glass and heats electrically; its koshering is by cleaning and heating on the highest setting for about a quarter of an hour.
Induction Cooktops
Unlike ceramic stovetops, where the heat source is the surface, in induction the heat originates in the pot, heated by a magnetic field. The chametz may be absorbed into the surface from food that overflowed and from residue stuck to the bottom of the pot.
Therefore, koshering is by cleaning and pouring boiling water. Additionally, to kosher from residue under pots, one should wet the bottoms of empty pots and heat them on the surface for about a quarter of an hour— “as it absorbs, so it expels.”
Oven
Clean the oven thoroughly and then operate it at the highest temperature for half an hour. Ideally, one follows the stringent opinion not to kosher the trays, since libun would require about 400°C, which could warp them. Therefore, one should use disposable trays and kosher the rack with the oven (ibid. 11:3).
In cases of need, one may kosher the trays at the oven’s regular maximum heat for half an hour, relying on the opinion that libun at the temperature of use suffices (Peninei Halakha, Pesach 10:5).
Pyrolytic Oven
Self-cleaning ovens that reach about 500°C do not require prior cleaning, since this is considered libun chamur, and suffices.
Barbecue Grill (Askalāh)
The body and the grate must be koshered according to their use, which is at the level of libun chamur. If gas—at the highest heat; if charcoal—with the largest amount normally used.
Microwave
Three stages:
1) Clean thoroughly of food residue.
2) Heat a bowl of water inside for about ten minutes on high to kosher by steam (“ke-bolo kakh polto”).
3) Clean and kosher the turntable or place a barrier between it and Passover food (Peninei Halakha, Pesach 11:5).
Dishwasher
Clean the filter, then run the dishwasher with racks on the highest heat—thus it is koshered (ibid.).
Dining Table
Tables are delicate and not used for very hot items, so cleaning suffices. However, since hot chametz sometimes contacts them, one should not eat on them during Passover without a tablecloth.
Some are meticulous to affix plastic or paper to the table as a fixed barrier. If dough is sometimes kneaded on it, a fixed covering is required. Otherwise, thorough cleaning suffices (ibid. 11:6).
Refrigerator
Since it is used with cold, the concern is only crumbs; therefore, cleaning suffices. Cracks that are hard to clean should be treated with soapy water to render crumbs unfit for a dog’s consumption, thereby nullifying their status as chametz.
Kitchen Cabinets
In the past, wooden shelves had cracks and were covered. Modern smooth shelves only require thorough cleaning.
Koshering Cutlery
Since they are sometimes placed in a kli rishon on the fire, they require hagalah in boiling water. Immerse each item for about three seconds. Ideally, rinse in cold water afterward, though it is not required (ibid. 10:11).
Koshering Pots
A pot cannot be koshered by boiling water inside it alone, because chametz may have been absorbed at the rim. Therefore, it must be immersed in a larger pot.
If this is not possible, fill it with water and bring to a boil, then add additional boiling water to cause overflow over the rim. The lid of the pot must be koshered by hagalah (purging in boiling water) in a larger vessel, or koshered by libun kal (light heating), similar to heating a frying pan over a low flame for two minutes, with the inner side of the lid facing the fire. In addition, the handles of the pot must be thoroughly cleaned with soap, and boiling water should be poured over them (ibid. 10:12; 10:9).
Frying Pan
Clean it thoroughly and kosher it by libun kal. That is, heat it over a gas flame at the same level of heat at which it is normally used for frying (ibid. 10:4–5).
Glass Utensils
Many of those of Sephardic descent have followed the lenient opinion to kosher glass utensils with rinsing alone, while many of those of Ashkenazic descent have followed the practice not to kosher glass utensils at all. However, in practice, it appears that the main position is the intermediate view, according to which the law of glass utensils is like that of metal utensils, whose koshering is by hagalah. One whose family custom has been to be lenient may continue their custom, and one whose family custom has been to be stringent, should continue their custom (ibid. 11:12).
Various utensils
Shabbat hot plate (plata): Clean it thoroughly, heat it on the highest setting for about an hour, and those who are stringent also cover it with aluminum foil, in order to create a barrier between it and the Passover pots (ibid. 11:4).
Shabbat urn and kettle: The custom is to kosher them by hagalah, lest crumbs of chametz have fallen into them. Their hagalah is done by filling them with water as much as possible, bringing it to a boil in the usual manner throughout the year, and pouring out some of the water through the tap or spout used for dispensing the water. It is good to first clean the urn of any limescale that has accumulated in it. When the lid is metal and it is customary to place challot on it to warm them before the Shabbat meal, the lid should be koshered in boiling water.
Coffee machine: Clean it, and heat the machine in its usual manner with hot water on the highest setting.
Silver goblets: The custom is to kosher them by hagalah in a pot of boiling water, lest chametz was absorbed into them together with a sharp beverage or strong wine. Since this is a remote concern, in a case of need, one may suffice with rinsing them, according to their primary use.
Baby bottle and pacifier: It is preferable to replace them, and in a case of need, they may be koshered by cleaning and pouring boiling water over them.
Dentures, plates, and braces: They must be cleaned thoroughly before the time when chametz becomes forbidden, and there is no need to kosher them by hagalah, because it is not customary to put boiling-hot foods or drinks into the mouth. Just as one eats with them meat and dairy foods relying on cleaning alone, so too, one may eat with them on Passover.
May it be God’s will that through the removal of chametz from all our utensils, we merit to rid ourselves of all preconceived notions and conceptions that hinder us from advancing in Torah and mitzvot, in Yishuv Ha’Aretz (settling the Land of Israel), and in the Ingathering of the Exiles, and may we merit redemption speedily in our days.
This article appears in the ‘Besheva’ newspaper and was translated from Hebrew.
