Refraining from Eating 

One should stop eating hametz two hours before midday and brush his teeth so no hametz remains.

Biur Hametz

Before the time that ownership of hametz is prohibited, the hametz must be destroyed. The method we customarily follow is to burn the hametz.  Another less common method is crumbling the hametz into small pieces and throwing it to the wind or into the ocean. 

• One must be very careful to make sure that the hametz is totally burned and inedible. 
•  If for some reason one is unable to burn the hametz, it must be destroyed by some other method. 
• If one has a lot of hametz and cannot burn it all, he may place it in a public garbage pail but not his own pail.

What Needs to be Burned?

• We burn the hametz that was collected at the time of Bedikat Hametz as well as any other remaining hametz. 
• If a person has a lot of hametz and a substantial loss will be involved if he destroys it, a Rabbi should be consulted regarding what may be sold to a gentile.
• Inedible hametz does not have to be destroyed and may be used on Pesah, i.e., cosmetics, powder, etc.

Bitul After Biur

After burning the hametz, it is necessary to recite the Bitul which is a declaration nullifying any leftover hametz that we may not have seen or removed during Bedikat Hametz.  The Bitul must be recited in a language which the person understands. 

• The Bitul may be recited up till an hour before midday.  The hours are derived by dividing the day into twelve parts, from dawn until nightfall (tz’ait).  Since most people are unfamiliar with these times, a Rabbi should be consulted (or a reliable calendar). 
• If a person is very far away from his home and therefore does not have access to his hametz to do biur, he must definitely recite the Bitul.  He declares in the Bitul that he is disowning his hametz.  The Bitul may be done up till an hour before midday to take effect, after that time it is ineffective and the Torah considers the hametz yours even though you do not wish to own it.