Possible Clues:

• Are Derby disposed to loaf?
• Use your loaf to have this in black, but not white
• Characters from Derby are upset by baker's product
• Reuben holder
• Bakery product made without wheat flour
• Dark bakery product
• *Deli supply
• Pumpernickel, eg
• Dense food dry with a beer drunk
• Type of whiskey bishop takes to study - presumably it can be used for toast?