If there was wheat/grains stored in these pyramids it wasn''t for public consumption. It was for the dead pharaoh and his priest and princesses to aid them on the other side.
I don't know................I understand that they stored food and wine, and basically everything he'd need in the afterlife.............but they did store food and grain for that afterlife.................
Did they use it to store food while the Pharoh is still alive.........don't know......... 4500 years ago.............who the hell knows.