Abstract. Structural differences between mar­ket classes and varieties of wheat will have a marked in­fluence on their mechanical properties. An analysis of the mechanical properties of mealy and vitreous grains was conducted on hard, vitreous durum wheat, variety Wascana from Canada and two Polish varieties: Delta (Soft White Winter) and Jara (Soft White Spring), which exhibited mealy and intermediate grain characteristics. Simple quasi-static compression tests were performed to measure the force, deformation and initial irreversible deformation, based on the compression curve. The results showed that mealy grains were less resistant to external loads than vitreous grains. But mealy grains were more elastic, and withstood greater deformation, than vitreous grains which exhibited greater maximal force but were 'brittle'.