I am making an Italian Buttercream recipe I have made dozens of times before without fail. Tonight, the stars must know that I am making my first wedding cake and IT WON'T WORK. For some reason, the sugar syrup is hardening up and the sugar is not dissolving.
The instructions are to put the sugar (3/4 lb) in a saucepan with 1/4 c water, stir to dissolve the sugar, bring to a boil and reduce the heat and boil it to 240 degrees. I have done it twice now and both times the sugar hasn't dissolved and it's hardened as soon as I've removed it from the heat. What is happening? Help help!

Sorry I can't help but here's a bump for you...

the recipe I have for IMBC you boil the sugar/water to 249. I don't know if that would help, but you could give it a shot.

well, after two failed attempts at the sugar syrup I raced to the grocery store and bought different sugar and a bottle of water. I used Domino superfine sugar and it worked. The sugar I had been using was a brand new 10 lb bag of Domino, so it said Pure Cane but I am suspicious that it wasn't. The only time this has ever happened before I was using cheap sugar that turned out not to say Pure Cane (so it was probably beet sugar).
Here's hoping tomorrow's icing turns out better than tonight's.
Thanks for your advice!

Sounds like your sugar solution was crystallizing. Make sure when your cooking sugar that you wipe down the sides of your pan with cold water and a clean pastry brush. This will help prevent the growth of crystals. Also, you can add about 2 T of corn syrup to the sugar mixture when it starts to boil. This will help it too. Hope this helps...!