I remember hearing that a knife can be kashered (from being treif) by sticking it in the ground. But I also know you can use the traditional kashering methods - Hag'ala (completely submerging the utensil in boiling water) and Libun (kashering something via heating to a high temperature).

I have 2 questions:

1) What is the logic behind the method of sticking the knife in the ground?

2) When is each method applied?

1 Answer 1


A knife used for grease is very hard to clean — or was so before modern sponges and cleaning agents. Sticking it in the ground in the prescribed way is (was) a means of cleaning, not kashering, it. One must then do libun or whatever if the knife was used in a way that requires kashering (SA YD 121:7).

As always, for a practical ruling, CYLOR.

  • 3
    . . . and thus the ground was expected to wipe off whatever particles were stuck to it.
    – WAF
    May 11, 2011 at 19:24
  • 2
    And I believe some recommend using a caustic cleaner and steel wool today.
    – Shalom
    May 11, 2011 at 19:24
  • Libun = putting a flame to the blade of the knife until it gets red hot. May 12, 2011 at 20:02

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