The glider pilot reported that he was about 5 miles from his destination airport and had enough altitude to make the field, but encountered sink and was unable to find additional lift. The pilot decided to conduct an off-field landing in a large open grass field. During the landing, the right wing tip hit the tall grass, which resulted in a ground loop when the glider was still several feet above ground. The nose yawed to the right and the glider impacted the terrain nose first. The wings, fuselage, and empennage were substantially damaged. The pilot stated that the accident could have been avoided if he had focused more on his choice of a landing spot and that he should have avoided landing in a field with tall grass. However, the pilot was likely unable to recognize the height of the grass in the field until the glider was low to the ground, and he selected the best possible landing site given what he knew at the time of the loss of lift.