Buckwheat hulls are the outer shell of a buckwheat seed and are left over after buckwheat seeds are processed. Their 3D structure does not compact and allows air to flow throughout the pillow. Therefore, buckwheat pillows do not retain stifling heat and moisture while sleeping.
The secret to the breathability these pillows is the shape of buckwheat hulls. Buckwheat hulls are pyramidal in shape. When piled together, like the inside a buckwheat pillow, there are spaces between the hulls. These pockets of air will help keep your head cool on warm nights. Air flow within buckwheat pillows also helps dispel any moisture from your head and pillow.