Oct 17, 2018· Dirt (the sturdiest bricks come from dirt with a clay content of 25 to 50 percent) Sand Straw, grass or pine needles Water Sunlight A mold to shape the bricks. Mix soil and water into a thick mud. Add some sand, then mix in the straw, grass or pine needles. Pour the mixture into your molds. Bake bricks in sunshine for five days or so.