afterwards. That water is just to dissolve the sugar and it all boils off. The dry method eliminates the need for the water.

I use the wet method for caramel, and I find it helps to use purified water. It's also important that the pan be absolutely clean. Also, I use Julia's trick of leaving the lid on the pot while it boils--the steam washes down the sides of the pan. Once it thickens a bit it doesn't splash as much and you can take the lid off to finish the boiling. I keep a brush with water handy too.

When you add cream to the caramel it hardens, and has to be stirred until it dissolves again. I wonder if perhaps, with a double recipe, you didn't get it dissolved again all the way?