Kashering Cutlery and Knives

All cutlery looks alike in the drawer, and it is not all kashered alike. What decides the method is how hot the food was that it touched, and in what kind of vessel.

Table cutlery

Knives, spoons and forks used for eating at the table — made in one piece with their handles, of metal, used in a kli sheini — are kashered by hagalah, or by the kli sheini route: pouring hot water from a kli rishon onto them while they sit in a kli sheini.

One detail about the water is worth having exactly right. It may be poured from an urn in which the water actually boiled. It may not be poured from a thermos or any other vessel in which the water did not boil. Hot is not the same as having boiled.

Serving and cooking utensils

Anything that went into a pot standing on the fire is a different case, and needs hagalah in a kli rishon:

• Cutlery used to stir food standing over the flame
• A fork used for frying, or into which something very hot was pushed
• Large serving spoons and forks that are put into pots while they are on the heat

And one step further still: a fork used to lift meat or other food directly off the fire needs libun — because it met food against the heat itself, with no liquid between.

So the same drawer can hold three different answers.

Cold-use knives

A knife used only cold — a bread knife, a vegetable peeler — is kashered by driving it into hard ground ten times, each time in a different spot.

Kitchen knives used to cut hot food, and knives used on sharp foods with something forbidden, need libun. Knives used at the table to cut food that is not boiling follow the table-cutlery rules above.

When cutlery cannot be kashered

Three situations, and they are common enough to check before you start.

A gap between blade and handle. Where there is a pit or crack at the join that cannot be properly cleaned, hagalah does not help — the residue is still in there. One may do libun kal at the crack to burn out what is lodged there, and then kasher normally. But if that libun would ruin the handle, the kashering does not work.

Handles of a different material. If the piece and its handle are not made as one, or the handle is of another material, hagalah does not help.

Plastic handles. The custom is not to kasher cutlery with plastic or similar handles at all. The same applies to any vessel whose handle is attached with a material likely to be damaged by the kashering.

Which covers a good proportion of a modern kitchen drawer, and is worth knowing before Pesach rather than during it.

What your own cutlery needs is a question for your rav.