I have a flan recipe that calls for carmelized sugar. I tried several times, following the recipe instructions, but the sugar never carmelizes. The recipe tells me to "combine 1 cup of sugar and 1/3 cup of water. Stir over low heat until sugar dissolves. Increase heat to high and cook, without stirring, until syrup turns deep amber in color." Well, I followed those exact instructions - three different times - and the disolved sugar turns into crystals again. Is there a special type of sugar I need to use? What am I doing wrong?