Both pot and pearl barley have been put through a pearling machine or pearler. The machine bounces the barley around a grinding wheel in order to remove the outer inedible hull and polish the kernel—this process is called pearling. The longer the grain stays in the pearling machine, the more polished it becomes.

Pot barley is pearled for a shorter amount of time and still has most of the barley bran intact.

Pearl barley is pearled for a longer amount of time—it is more refined and has most of the bran removed. While pearl barley has most of its bran removed, barley fibre is found throughout the entire kernel so pearl barley is still a very healthy option.