How to Kasher Your Kitchen for Pesach

The following halachot were prepared by Rabbi Yaron Ashkenazi, Spiritual Supervisor at “Kav HaHalacha.”

Koshering Kitchen Utensils for Pesach

Any utensil that is used during the year may have absorbed the taste of chametz. Therefore, anyone wishing to use it on Pesach must kosher it properly.

The method of koshering depends on how the utensil is generally used. This follows the Talmudic principle: “As it absorbs, so it releases” (Pesachim 74).

This rule is derived from the Torah (Bamidbar 31:23): “Anything that goes through fire shall be passed through fire… and anything that does not go through fire shall be passed through water.”

Thus, utensils used only with cold foods require only washing. Utensils used with hot foods require koshering through boiling (hagalah), and items used directly over fire require libun (intense heating).

Below is a detailed guide by category.

Oven

Since ovens generally absorb only steam rather than direct chametz contact (though crumbs may occasionally fall inside), they may be koshered as follows:

• Wait 24 hours from last use.

• Thoroughly clean all interior surfaces.

• Heat the oven at maximum temperature for at least one hour.

Oven Trays

Oven trays absorb chametz directly and require libun chamur (intense heating until sparks fly), which is generally impractical. Therefore, trays should be replaced for Pesach.

Self-Cleaning (Pyrolytic) Oven

A pyrolytic oven (reaching over 500°C) may be koshered by running the self-clean cycle with trays inside. Afterward, wipe clean. Everything becomes kosher for Pesach.

Stovetop (Gas Burners)

• Clean the base surface thoroughly.

• Cover it with thick aluminum foil.

• No need to pour boiling water.

There is no need to dismantle burners to reach internal wiring areas, since food does not reach there; the nullification of chametz suffices.

Grates

• Preferably kosher through hagalah.

• Alternatively, pour boiling water and cover with foil.

• If foil tears during Pesach, replace it.

Burners

Require only washing, since they are constantly exposed to fire and do not absorb.

Ceramic / Halogen Cooktops

These are treated like glass. Washing suffices. One who wishes to be stringent may heat them empty.

General Rules for Hagalah (Koshering in Boiling Water)

1. Utensils must be completely clean without residue or baked-on spots.

2. Attached handles do not need removal, but screws and crevices must be cleaned.

3. If koshering meat and dairy utensils together, add dish soap to the water.

4. Procedure:

• Bring water to a full boil.

• Submerge utensils briefly until water returns to a boil.

• Remove and rinse with cold water.

Ideally, hagalah should be performed at a certified koshering station due to technical details.

Pots and Frying Pans

Since they absorb through liquid cooking, hagalah in boiling water suffices.

Glass Utensils

Glass does not absorb. Washing alone suffices — even for cookware.

However:

• Ashkenazic custom is to treat glass as non-kosherable and purchase separate Pesach glassware.

• If residue spots cannot be removed, the item should not be used.

Teflon Pans

May be koshered via hagalah, as Teflon is treated like plastic (according to Rabbi Ovadia Yosef).

If absorbed from non-kosher foods (not chametz), libun is required.

Grills, Barbecue Grates, Liver Grates

Items used for dry heat without liquid require libun chamur (intense heating until sparks fly).

Because modern equipment is delicate, these are generally replaced for Pesach.

Gas grills that reach over 400°C may be heated at maximum for 30 minutes after thorough cleaning, though replacing grates is preferable.

Liver-specific grates used exclusively for liver (no chametz use) require no koshering.

Cutlery, Plates, Cups

• Metal cutlery: Pour boiling water.

• Earthenware/porcelain plates: Cannot be koshered.

• Plastic plates: Pour boiling water.

• Glass plates/cups: Washing suffices (Sephardic custom).

• Earthenware cups: Cannot be koshered.

Countertops

Modern countertops are composite stone and adhesive. They are not meant for hot pots.

• Washing suffices.

• Pouring boiling water may cause cracking.

• No need to cover unless frequently used for hot pots.

• Portable stone trivets used for hot pots should be poured over with boiling water or covered.

Sinks

Since boiling water is often poured into sinks, they require:

• Pouring boiling water from a kli rishon (directly heated vessel).

• Preferably repeat three times (due to ceramic components).

Kitchen wall tiles require only washing with soap.

Faucet and Strainer

• Faucet: Washing suffices.

• Clean crevices well.

• Sink strainer: Clean thoroughly and preferably pour boiling water over it.

When koshering sink:

• Dry sink first.

• Begin from the drain upward.

Refrigerator and Freezer

Washing suffices. No need to dismantle internal plastic components; nullification covers unreachable crumbs.

Kitchen Cabinets

General cleaning suffices. No need to line with paper or foil.

Electric Kettle

If used only for water — washing suffices.

If citric acid (lemon salt) was used (which may derive from chametz), fill to brim and boil until water overflows.

Shabbat Urn

If used only for water — washing suffices.

If bread or pastries were heated on top and crumbs may have fallen inside:

• If the lid has holes — cannot be koshered.

• If no holes — may be koshered via boiling.

Sandwich Toaster

Requires intense libun — generally not practical. Replace for Pesach.

Toaster Oven

Kosher like a regular oven. Trays require libun chamur.

Blender / Meat Grinder

• If used only for cold chametz — washing suffices.

• If used with hot chametz or sharp foods — requires hagalah.

Microwave

• Clean thoroughly.

• Place a cup of water with a little soap inside.

• Run until water boils and steam fills the interior.

Dishwasher

• Clean thoroughly (no residue).

• Run an empty cycle with detergent at highest heat.

Mixer / Whisk / Water Dispensers

• If used only cold — washing suffices.

• If whisk used with flour — cannot be koshered (flour may enter vents).

• Mixer bowls used cold — washing suffices.

Filtered water systems require only external cleaning.

Espresso Machine

Since espresso pods may contain chametz:

• Kosher via hagalah the brewing components and milk frother.

• Remainder of machine requires washing.

Preparing for Pesach properly ensures that our kitchens are free from chametz in accordance with halacha — allowing us to celebrate the festival with peace of mind and spiritual readiness.