Hametz (Leaven) During Pesach

Every article of food, which contains leaven, even if the bulk was removed and only the taste remained, must not be kept during the week of Pesach (Passover).

As well as all vessels that has had leaven in it is to be removed from the home or dwelling or should be thoroughly scrubbed and rinsed in the forenoon before Pesach, in such a manner that no leaven is visible on them and not concealed in any place which is not frequented. It is best, however, to lock them up in a separate room and hide the key until after Pesach.