The Chametz found during Bedikas Chametz must be burned.

This is done on Erev Pesach in the morning, which this year falls out on April 22nd.

The burning of the Chametz should be done without adding or pouring any lighting fluid over the Chametz, which would then make it inedible, and thus nullify the mitzvah of destroying the Chametz. At the time of the burning, the following declaration must be made:

 כל חמירא וחמיעא דאיכא ברשותי, דחזיתיה ודלא חזיתיה (דחמיתיה ודלא חמיתיה) דבערתיה ודלא בערתיה לבטל ולהוי (הפקר) כעפרא דארעא. 

Any Chametz or Leaven that is in my possession, whether I have recognized it or not, whether I have seen it or not, whether I have removed it or not, should be annulled and become ownerless, like the dust of the earth.