824. Grain in the Well

117:2 If kernels of grain were found in a well, one should not take water from it except in a case of great need, such as if there is no other water available. If a piece of bread was found in the well, it is prohibited to use it even if no other water is available. In such a case, even filtering the water does not help. (Dough in the well is the same as a piece of bread - Mishnah Brurah 467:62 - but a whole loaf is the same as finding grain - Shaar HaTziyon 110.)

117:3 When singeing chicken to remove the feathers, the practice is not to use straw containing ears of grain. This is done out of concern that one of the kernels may have become chometz. We therefore singe chicken using herbs or stalks with the ears of grain cut off. If one did use a stalk of grain then, after the fact, the chicken is permitted (even if we know that the stalk contained chometz because it never actually touches the chicken - MB 465:12). One must be careful to remove the crop of the chicken before singeing it. (On Pesach, the truly scrupulous will cut a chicken in half and inspect it before salting it - MB 467:86.)