Sprinkle the yeast over the water in a small bowl. Set aside.

Combine the rye flour with all-purpose flour in a large bowl. Stir in the salt. Mix in the yeast mixture to make a soft dough. Turn dough out onto a board floured with rye meal. Knead lightly, mixing in rye meal as needed. Shape dough into a fat roll, and cut into 12 sections. Roll each section into a ball; cover balls with a towel and let rise 20 minutes.

Preheat oven to 425 degrees F (220 degrees C). Lightly grease 2 baking sheets.

On a floured board, roll out each ball into a flat round about 4 inches in diameter. Place rounds on prepared baking sheets and prick with a fork.

Bake in preheated oven until lightly browned, 8 to 10 minutes. Cool on a rack.