Usually, when a grain is sold as “semi-pearled” or “pearled,” it will cook faster than “whole” grains. But farro is an exception.
Usually, when a grain is sold as “semi-pearled” or “pearled”—that is, when its bran layer has been lightly abraded or almost completely rubbed away—it will cook faster than “whole” grains that have an intact bran layer. But farro is an exception. We found that whole farro often cooks faster and more consistently than the processed varieties. That’s because the whole grain’s heavier seed coat is rigid, so once water gets inside the grain, steam pressure builds up and causes it to rupture at the ends. Thus, water flows in a bit faster and speeds up cooking time. As for why processed grains don’t cook consistently, pearling is not a standardized process; manufacturers remove as much of the grain’s bran layer—and label it—as they wish.