KASHERING OVERVIEW

1. LIBUN GAMUR – COMPLETE GLOWING

APPLICATION: Items used directly on a stove top or grill or in the oven with food that does not contain liquid
EXAMPLES: Baking pan, roasting pan, grill
METHOD: The item must be heated, e.g. using charcoal or an industrial blow torch, until every part of it becomes red hot.
Note: It is highly recommended that this method be employed only by someone with experience.

2. LIBUN KAL – MODIFIED GLOWING

APPLICATION: This method can be used in place of hagola and may also be sufficient in certain circumstances when libun is required.
EXAMPLES: Some types of ovens (See Kashering & Cleaning Guide)
METHOD: A kli must be heated until straw or a feather touching the other side of the kli, begins to burn.
Note: One can test to see if the kli has reached libun kal by sprinkling water onto it. If the water sizzles then the item has been kashered with libun kal.

3. HAGOLA – BOILING

APPLICATION: Keilim used directly on a stove top or grill or in the oven with food that does contain liquid
EXAMPLES: Pots, stirring utensils, flatware when used on the fire with liquid foods (regular flatware also generally requires hagola).
METHOD:

Clean thoroughly to remove all dirt, labels, glue, and tangible rust. Any part of the kli that cannot be cleaned properly, e.g. crevices, requires libun kal.
The item should not be used for 24 hours. (If this is not possible, ask your rabbi.)
If the pot used for kashering is not a Pesach pot, the minhag is to kasher the pot. This is performed as follows:
- A. Make sure that the kashering pot is clean and not used for 24 hours.
- B. Fill the kashering pot to the brim with water and heat it up to a rolling boil.
- C. Discard the water – at this point your kashering pot is kosher for Pesach.
- D. Fill the kashering pot and boil once again. This pot is now ready for kashering.
Immerse each kli, one at a time, in the boiling water. If you are kashering several keilim, ensure that the water remains boiling before inserting each kli.
If the water becomes murky, then it must be changed.
If an entire kli does not fit into the kashering pot at one time, it may be kashered in sections. A large pot can be kashered by using the method described above for the kashering pot and, in addition, it is recommended to drop a preheated stone that is glowing red (“even meluban”) into the boiling water to make it overflow.
After kashering is complete, the kli should be rinsed in cold water.
Once all keilim have been kashered, the kashering pot should be kashered once again if it is to be used on Pesach. (This can be done immediately; no need to wait another 24 hours.) Ensure that the kashering pot is clean and follow steps B and C above.

4. IRUI ROSCHIM – POURING HOT WATER

APPLICATION: Keilim upon which hot chametz was poured
EXAMPLES: Sinks, counters
METHOD:

Clean the keilim thoroughly.
The kli should not be used for 24 hours. If this is not possible, ask your rabbi.
Pour boiling water onto every part of the kli using a kettle or a pot of water that has been taken directly from the stove. It is recommended to pour the boiling water over an even meluban which allows the water to sizzle on contact with the kli. (See step 3 above, Hagola, concerning the use of a chametz pot for kashering purposes.)

5. MILUI V’IRUI – SOAKING

APPLICATION: Keilim used exclusively for cold chametz
EXAMPLES: Drinking glasses
Note: If one is able to buy separate glasses for Pesach, this type of kashering should be avoided.
METHOD:

Clean the kli thoroughly.
Immerse the kli in cold water, e.g. in a bathtub or basin, or fill the kli to the top with cold water.
Change the water every 24 hours, for three cycles, for a total of 72 hours.

KASHERING & CLEANING GUIDE

OVENS

A. SELF-CLEANING OVENS

Clean all parts of the oven where the heat of the self-cleaning cycle does not reach – mainly edges and sides of the doors and under the gasket.
Run the self-cleaning cycle for at least two hours.
During Pesach, avoid placing food directly on the racks or on the door unless they are covered with aluminum foil.

B. CONVENTIONAL OVENS

Use an oven cleaner to thoroughly clean the entire oven, including the racks and doors.
Turn the oven on to its highest setting for one and a half hours (libun kal).
Turn the oven on to broil for half an hour.
It is preferable to cover the racks with aluminum foil so that no pots or pans touch them directly.

C. CONTINUOUS CLEANING OVENS

Despite its name, don’t assume that this type of oven is always clean.
Clean the oven thoroughly. (Caution: Check the manual for what type of cleansers you should use.)
Kasher in the same way as a conventional oven.

D. MICROWAVE OVENS
It is best not to kasher a microwave oven. If it must be used, it should be kashered as follows:

Clean the oven thoroughly to remove all dirt and food residue. If any part of the interior cannot be accessed to clean properly (e.g. crevices), then the microwave should not be kashered.
The oven should not be used for 24 hours.
Place a container(s) of water in the oven and boil it until the oven fills with thick steam.
The glass tray should either be changed or completely covered with a material that is microwave safe.
Some people also either cover the 6 walls of the microwave (Caution: Do not block any vents) or completely double wrap any food before heating it.

STOVE TOPS

A. ELECTRIC & GAS
Clean the entire surface of the stove top and all its parts—mainly the electric burners, chrome rings, gas grates, drip trays, and knobs.

Electric Burners – Turn them on to the maximum setting (until they are glowing red hot) for approximately 10 minutes.
Chrome Rings – Immerse in a pot of boiling water. Alternatively, one can place a wide pot (with water so as not to burn the pot) on the element while the burners are turned to maximum heat in order to spread the heat to the chrome rings.
Gas Grates – Kasher them with libun kal by one of the following methods:
- Place them in the oven while it is being kashered. (Caution: If the oven is being kashered by using the self-cleaning cycle, verify that the grates can withstand the heat and will not experience discolouration.)
- Move them around the flame until every part of them has been heated to libun kal. (Caution: Use tongs and protective gloves.) Alternatively, one can place a wide pot (with water so as not to burn the pot) on the grate while the burners are turned to maximum heat in order to spread the heat to the grates.
Drip Trays – Put them in the oven while it is being kashered.
Knobs – Kasher them with hagola or cover them (if they could come into contact with food or steam from pots).
Surface – Cover the entire surface with heavy aluminum foil or a Pesach blech so that only the burners are exposed.
Backsplash – Cover with heavy aluminum foil. (Caution: Be careful not to block any vents.)
Oven Hood – Clean thoroughly. The oven hood does not have to be covered unless it is very low (to the point that when the steam from the pot below reaches it, the steam is still hotter than 113°F, yad soledet bo).

B. GLASS TOP RANGE (including Corning, Halogen and Ceran)

Burners — Turn them on to their maximum setting (until they are glowing red hot) for approximately 10 minutes.
Cover the rest of the surface around and between the burners with material that will not easily tear. (Caution: do not cover the stove with a Pesach blech as it can cause the glass to crack.)

DISHWASHERS

A. ENAMEL INTERIOR
These types of dishwashers may not be kashered.

B. METAL INTERIOR
It may be possible to kasher a dishwasher with stainless steel walls; however, because of the various issues involved, this should only be done after consulting with, and under the direction of, your rabbi.

SINKS

A. STAINLESS STEEL SINKS

Clean every part thoroughly—mainly basin, knobs, faucet, and drain area. Be sure to clean the spout on the faucet.
Remove the faucet aerator and clean well.
Pour a strong chemical cleaner down the drain and into any crevices that cannot be cleaned properly.
Do not use the sink with hot chametz for 24 hours.
Dry the sink prior to kashering.
Kasher with irui roschim by pouring boiling hot water on every part of the sink, including the knobs, faucet and faucet parts. If the pot used for kashering is not a Pesach pot, the minhag is that the pot itself should first be kashered. (See Hagola above)
Some people move an even meluban around the sink as the water is being poured.
It may take a few refills of the kettle or pot to kasher the entire sink.
Faucets and Extendable Faucets – An alternative way of kashering this part of the sink is to quickly dip it into the kashering pot. (Caution: Plastic parts could warp if kept in the pot too long.)
Stoppers and Strainers – Replace for Pesach. (If necessary, they may be cleaned well and kashered with boiling water.)
Instant Hot Water Device – Pour boiling hot water over it while letting hot water run from it.
Soap Dispenser – Empty it of all soap, flush out any remaining soap with water, and pour boiling water over the entire dispenser.
Some people cover the entire area of the sink after kashering it or place an insert in the sink.

B. ENAMEL, PORCELAIN & CORIAN SINKS

Sinks made of these materials cannot be kashered.
Clean them thoroughly and use a strong chemical cleaner on the sinks and down the drain.
Line the walls and bottom of the sink with contact paper or heavy aluminum foil. Then, place a rack on the bottom and wash dishes in a dishpan placed on top of the rack. Some people place an insert in the sink.

COUNTERTOPS

A. MATERIALS THAT CAN BE KASHERED
Granite / Marble / Metal / Stainless Steel / Wood

To kasher these counters:

Clean them thoroughly.
Do not put anything hot on them for 24 hours.
Kasher with irui roschim by carefully pouring boiling water on the entire area from a kettle or from a pot taken directly from the stove. If the pot used for kashering is not a Pesach pot, the minhag is that the pot itself should first be kashered. (See Hagola above)
Some people cover these types of counters even after kashering them. Alternatively, they move around an even meluban or hot iron as they pour the hot water.

B. MATERIALS THAT CANNOT BE KASHERED
Corian / Enamel / Formica / Plastic / Porcelain / Surreal / Engineered Quartz*

Before using these counters:

Clean them thoroughly.
Cover them with a thick waterproof material that will not rip easily while you are working on them.
Some people kasher these counters as outlined above before covering them.

* Engineered quartz countertops such as Caesarstone and Silestone are made from a combination of stone, synthetic resins, and pigments. There are differences of opinions as to whether these materials can be kashered and a rabbi should be consulted.

REFRIGERATORS & FREEZERS

Clean every surface and all parts thoroughly using a cleanser that will render inedible any tiny crumbs that may have been missed. Often, shelves will have to be removed to effectively clean all cracks and crevices.
Some have a custom to cover surfaces that may directly touch food.

CUPBOARDS, DRAWERS & SHELVES

Clean thoroughly with a cleanser that will render inedible any tiny crumbs that may have been missed.
Some have a custom to cover surfaces that will directly touch food.

TABLES & CHAIRS

Clean thoroughly. Cover tables with a thick material that won’t tear easily and through which spills won’t easily penetrate. Covers should be fastened securely.

FLATWARE

Requires hagola (See Kashering Overview)

MISCELLANEOUS ITEMS

A. TABLECLOTHS & DISH TOWELS
Launder with soap and hot water. (Plastic tablecloths should not be kashered.)

B. HIGHCHAIRS
Clean thoroughly and cover tray. Some pour hot water on the tray before covering it.

C. RINGS
Clean thoroughly and pour boiling water on them (irui roschim).

D. CANDLESTICKS & TRAY
Clean thoroughly. Do not wash them in a sink that has already been kashered for Pesach. (The same applies for flower vases that were on the table during the year.)

ITEMS THAT CANNOT BE KASHERED

Blech
Bottles with Narrow Necks
Ceramic
China
Colander/Strainer/Sieve
Crock Pot
Food Processor
George Foreman Grill
Grater
Hot Plate*
Mixer
Plastic Tablecloths
Sifter
Toaster/Toaster Oven
Warming Drawer
Wooden Cutting Board

* Hot plates can be used for Pesach if the following is done: Clean thoroughly and turn the hot plate to high for an hour. Make sure that it is covered very well in a way that the cover won’t rip and food will not come into direct contact with the hot plate.

KASHERING NOTES

Kashering (except for libun gamur) should be performed before the latest time to eat chametz. If this is not possible, ask your rabbi.
Typically, it is not permitted to kasher a meat kli to use for dairy or vice versa. However, once a kli is kashered for Pesach, it may be designated for either use.
Since kashering can involve boiling hot water, red-hot burners, or even a blow torch, safety is an important concern. It is best to use protective gloves and tongs while kashering. Children should be kept away from the area where you are working.
When in doubt, ask your rabbi. Although this is an important rule all year round, it is crucial when it comes to Pesach as the laws are more complex and more stringent.
These guidelines are for kashering chametz items for Pesach use only. To kasher items all year round that may have become non-kosher (i.e. meat utensil that absorbed milk), consult your rabbi as the guidelines may differ slightly.
Due to the complexities of the kashering process, to the extent that it is feasible, it is best to have separate keilim for Pesach.

TEVILAT KEILIM

Immersing Dishes & Utensils in a Mikvah

In a kosher kitchen, many types of dishes and utensils must be immersed in a mikvah before they may be used. Tevilat keilim is independent from kashering. The basic difference between the two is that kashering refers to various methods of extracting or burning absorbed substances, while tevilat keilim is a ritual of sanctifying the utensil. Based on this discrepancy, tevilat keilim has different applications, requirements, and guidelines than kashering.

Ownership requirements

The function of tevilat keilim is to sanctify a vessel that is now owned by a Jew. Consequently, if an item was originally made by a Jew, and has always been owned by a Jew, the item would not require tevilah (immersion in the mikvah). Conversely, if an item is owned jointly or in a partnership with a non-Jew, it would also not need tevilah. If later the Jew becomes the exclusive owner, the item would then need tevilah.

Tevilat keilim is required only on utensils that are considered klai achila, utensils used for food preparation or mealtime. Based on this classification, a storeowner who sells these utensils should not tovel them. This is because the storeowner relates to them as klai schorah, store inventory, and not as klai achila. Once the customer buys the utensil, the utensil is now considered klai achila, and the utensil could now be tovelled.

Questions arise when sending a gift if the sender could do the tevilah. As the scenarios can be quite complex, one should consult their rabbi or contact the COR with the specific question.

Utensil requirements

We are required to tovel (immerse in a mikvah) items that come into direct contact with food both during preparation and at mealtime. Oven racks generally do not come into direct contact with food, and would, therefore, not require tevilah, but the racks from a toaster oven which do directly touch food would require tevilah.

To require tevilah, items must be made of metal (including aluminum, brass, copper, gold, iron, lead, silver, steel, and tin) or glass (including Pyrex, Duralex, and Corelle). Wood, plastic, rubber, and unglazed earthenware do not require tevilah.

Preparing the utensil

For the tevilah to be valid, the item must be immersed in the mikvah waters without any interference. The item must, therefore, be prepared accordingly. All labels and stickers that one plans to remove when using the item must be removed before tevilah. After the sticker is removed, any residual adhesive that is left on the item must be removed as well. On a practical note, WD-40, nail polish remover, and Goo Gone are known to be effective in adhesive removal. Also, if there are many items to tovel, it is recommended to prepare the items before going to the mikvah.

Bracha

Generally, one must make a bracha (blessing) before performing the mitzvah of tevilat keilim. One should hold the item or one of the items that is to be tovelled while making the bracha. If one item is being tovelled the bracha is “Baruch… asher kedishanu bemitzvotav vetzivanu al tevilat keli.” If many items are to be tovelled the bracha changes to “Baruch… asher kedishanu bemitzvotav vetzivanu al tevilat keilim.”

There are a number of items that require tevilah where a bracha is not said. This could be for a number of reasons. For example, if there is an uncertainty in halacha if an item requires tevilah, then tevilah would be done without a bracha. Many of these items are listed in the accompanying chart.

Tevilah procedure

It is preferable to wet one’s hand before tovelling the item, and if possible to do this before making the bracha. The item being tovelled must be totally immersed with the mikvah waters touching the entire item both outside and inside. The entire item must be under water at one time and may not be immersed in stages. One must be aware when tovelling many items simultaneously that the pile is not weighed down in a way that water cannot reach all the items.

As with any matter in halacha, if a question arises or if you need further guidance, consult your rabbi or contact COR. ∎

Did you know?

Some of the most common questions that arise pertaining to tevilat keilim concern tovelling small electrical appliances. Typical sandwich makers, hot water kettles, and urns require tevilah. Discuss with your rabbi or COR how to practically tovel these appliances. For example, how much of the appliance must be immersed? Does the cord have to be immersed as well?

When it comes to appliances with a digital panel, e.g. a Keurig coffee brewer, there is a greater concern that these items would be ruined with tevilah. Taking this into account, there is a valid halachic claim that tevilah is not required. As mentioned in the article, if an item is partially owned by a non-Jew, it does not require tevilah. Therefore, under the circumstances, it would be advisable to sell a percentage of the appliance to a non-Jew. To receive instructions on how to properly administer such a transaction, talk to your rabbi or call COR to obtain a contract which has been designed specifically for this purpose.

Tevilah chart

Item	Tevilah Requirement	Bracha Required?
Aluminum Pans: to be used once	No Tevilah Required	–
Aluminum Pans: to be used more than once	Preferable to Tovel	NO
Barbecue Grates	Tevilah Required	YES
Blech	No Tevilah Required	–
Blender	Tevilah Required	YES
Can Opener	No Tevilah Required	–
Ceramic Dishes (e.g. coffee mug)	Preferable to Tovel	NO
China	Preferable to Tovel	NO
Cookie Cutters	Tevilah Required	NO
Cooling Racks	Tevilah Required	NO
Corkscrew	No Tevilah Required	–
Corningware	Tevilah Required	NO
Crock Pot: ceramic insert	Preferable to Tovel	NO
Crock Pot: metal insert	Tevilah Required	YES
Crock Pot: glass lid	Tevilah Required	YES
Dish Rack	No Tevilah Required	–
Earthenware, non-glazed	No Tevilah Required	–
George Foreman Grill	Tevilah Required	YES
Glass	Tevilah Required	YES
Hot Water Urn	Tevilah Required	YES
Meat Tenderizer Hammer	Tevilah Required	NO
Meat Thermometer	No Tevilah Required	–
Microwave – Turntable Only	Tevilah Required	YES
Mixer Beaters: exclusively with not yet edible food (e.g. dough)	Tevilah Required	NO
Mixer Beaters: at times with already edible food (e.g. ice cream)	Tevilah Required	YES
Oven Racks	No Tevilah Required	–
Peeler	Tevilah Required	YES
Plastic	No Tevilah Required	–
Popcorn Popper	Tevilah Required	YES
Porcelain Enamel	Preferable to Tovel	NO
Sandwich Maker	Tevilah Required	YES
Spatula	Tevilah Required	YES
Stoneware, glazed	Preferable to Tovel	NO
Styrofoam	No Tevilah Required	–
Tea Kettle	Tevilah Required	YES
Teflon Coated Pots	Tevilah Required	YES
Toaster Oven – Racks & Tray Only	Tevilah Required	YES

Kashruth Council of Canada | www.cor.ca — 2025-5785 Passover Guide, pp. 31–37

COR, the Kashruth Council of Canada, is one of the world’s largest kosher certification agencies, certifying thousands of products, restaurants, and facilities. Learn more at cor.ca, or read about our certification services at corkosher.com.