Question:
If I have a loaf of bread that if I pick up one side (before making a slice in it), it will fall apart, is that a problem of not being shalem?
Answer:
If a loaf is whole and it doesn’t have any cracks or cuts in it there is no need to check it. Checking a cut or cracked loaf if only a means to determine if the crack separated the two sides of the loaf, however if the loaf is whole this test doesn’t apply. We don’t have to check a wedding challah, by picking it up from one side, although if we will it most probably will break.
Sources:
O:CH 167-1, M:B 6.