Take some leftover white bread (e.g., toast bread, French bread, pita bread, or whatever you have on hand).
Put the dry bread in a blender or food processor.
Crumb the bread. Start at low speed and gradually increase it.
If you want both fine and coarse breadcrumbs, you can divide the batch and sift one portion.
Spread the two types of breadcrumbs on separate baking sheets with parchment paper.
Dry the breadcrumbs in the oven for 30 minutes at 100 degrees Celsius (212 degrees Fahrenheit) without fan.
Let the breadcrumbs cool completely before putting them in bags.
Perfect for breading poultry, fish, and pork or whatever you need breading for.