Cut the crusts off the bread, if desired. If you prefer more variation in color for your breadcrumbs, leave on the crusts.
Arrange the bread in a single layer on a baking sheet. Once the bread is dry and barely starting to brown, about 10 minutes. Remove from the oven and let it cool.
NOTE: If your bread has been sitting around for a couple of days, it will likely not be necessary to dry it in the oven.
Break the bread into 1 to 2 inch pieces and place in the bowl of a food processor. You may need to do this in two batches.
Pulse until the breadcrumbs reach the desired consistency. I like my breadcrumbs to have a mixture of pebble-sized pieces as well as finely ground crumbs, but use whatever consistency suits your needs the best.
Notes
The breadcrumbs will stay fresh in the pantry for up to a week or in the freezer for up to 6 months, provided they are packaged in an airtight container or heavy-duty freezer bags.See the post above for seasoned breadcrumb ideas.