Stage 1: Kitchen Assessment
Before kashering begins, the kitchen is reviewed to determine:
Which surfaces and appliances require kashering
The material of each item
How each item was used (hot, cold, direct heat, or with liquid)
Whether the kashering is for year-round use or for Pesach
Stage 2: Thorough Cleaning (Preparation)
All items must be completely clean before kashering.
This includes:
Removing all food residue, grease, and buildup
Cleaning cracks, seams, corners, and hidden areas
Ensuring appliances are free of residue inside and out
Cleaning is a required preparation step. Kashering cannot be performed on dirty surfaces.
Stage 3: Waiting Period (When Required)
In many cases, a 24-hour waiting period is required between the last use with hot food and the kashering process.
This depends on prior usage and halachic requirements.
Stage 4: Kashering by the Appropriate Halachic Method
Each item is kashered using the method that corresponds to how it absorbed taste:
Hag’alah (Boiling Water)
Used for items that absorbed taste through hot liquid, such as:
Metal utensils
Pots
Certain sinks
Irui (Pouring Boiling Water)
Used for:
Countertops
Sinks (depending on material)
Boiling water is poured directly over the surface, often together with a heated stone to maintain boiling temperature.
Libun (Direct Heat)
Used for items exposed directly to fire or intense heat, such as:
Stovetops
Grates
Certain oven components
The level of libun required depends on prior use.
Appliance-Specific Kashering
Ovens: Kashered according to halachic guidance and oven type
Cooktops: Kashered according to their usage and construction
Sinks: Kashered based on material and use
Dishwashers: Require specific procedures and halachic approval
Items that cannot be kashered must be replaced or properly covered.
Stage 5: Covering (When Required)
For Pesach or for materials that are difficult to kasher, countertops and other surfaces may be covered with suitable, heat-resistant coverings to create a halachically acceptable surface.
Stage 6: Final Verification
After kashering:
All surfaces and appliances are reviewed
The kitchen is confirmed to meet halachic standards
The kitchen is approved for kosher use
Only after this verification is the kitchen considered fully kashered.
Nachman Harris. Kosher Expert.
Available for any of your questions
