Refrigerating bread before grating it helps to firm it up, making it easier to grate into fine, even crumbs without crumbling or becoming doughy. This is because the cold temperature reduces the bread's moisture content and increases its structural integrity.
Fresh bread, especially soft varieties, can be difficult to grate finely. Its soft texture tends to compress and clump together, resulting in uneven crumbs or a doughy mess. Refrigeration addresses this issue by:
Reducing Moisture: The cold temperature in the refrigerator slows down moisture migration within the bread. This slight drying effect makes the bread firmer and less sticky.
Strengthening Structure: Chilling the bread firms up the gluten structure, providing more resistance during grating. This allows the grater to produce finer, more uniform crumbs.
Preventing Clumping: The firmer texture prevents the bread from compressing and clumping together as it's being grated. This results in a lighter, more airy crumb.
For best results, refrigerate the bread for at least 30 minutes to an hour before grating. You can also freeze the bread for a shorter period (15-20 minutes) for a similar effect, but be careful not to freeze it solid.
Use the coarse side of a box grater for larger breadcrumbs and the fine side for panko-style crumbs. Avoid using a food processor, as it can easily turn the bread into a paste instead of crumbs.