Success!  The secret is the heat.  DAP seems to provide the sugars a chance to crystalize so I left them out.  I’ll try yeast nutrient once I have some (tomorrow) to provide some amino acids for Maillard reactions but until then, caramel is good enough.  Here’s the new recipe:

1 lb sucrose
2 c water
1/4 tsp citric acid

Heat in a heavy bottomed sauce pan on high heat until the temperature of the mixture reaches 240 degrees.  Reduce heat and continue to heat until the temperature reaches 285 degrees.  Hold within +10/-5 degrees until desired darkness achieved.  Thin with 1/2 cup water to form a thick syrup – add cautiously, the mixture will flash steam.  Pour into a container and cover.  There’s a bit over a pound of sugar in the mixture for calculation purposes.

The syrup should keep a long time with no preservative or cooling.