Preheat oven to 250° F
Once the oven is hot, lay bread slices directly on the oven rack.
Toast for 30-60 minutes, or until bread is completely dry and golden brown.
Break toasted bread slices into smaller pieces.
Grind in the food processor.
Occasionally stop to sift breadcrumbs through a strainer.
Send large bread chunks back through the grinder.
Store in an airtight container.