Combine the sugar and water until the texture is even. The sugar should still be crumbly, just slightly moistened. If it is watery, you have put in too much water and should add more sugar. Measure about 1 heaping teaspoon per cube and press the mixture down firmly into the mold. Let the cubes sit at room temperature overnight to harden, then remove from molds. Store in an airtight container at room temperature for up to two years.
