Buckwheat hull pillow

A buckwheat hull pillow is filled with the hard outer shells of buckwheat seeds instead of foam, fiber, or feathers. Because the hulls are small, firm, and irregularly shaped, they do not pack together tightly, leaving gaps between them where air can move freely through the pillow.

That open structure is what makes buckwheat pillows sleep noticeably cooler than memory foam pillows, since heat does not build up against the head and neck the way it does in a solid foam block. The firm, moldable fill also holds its shape through the night rather than compressing flat, which is part of why buckwheat pillows are popular with side and back sleepers who also run warm.

The main adjustment for new buyers is the feel and weight, since buckwheat hulls are firmer and noisier when you move than foam or down, which can surprise someone expecting a soft pillow. Buying one with an adjustable fill level, so hulls can be added or removed, makes it easier to dial in both loft and firmness.