Post #528773 by Sparkle Mark on Fri, May 7, 2010 11:58 PM

Whether or not it's boiling is relative to your elevation.
Use a candy thermometer.
I will typically take a syrup up to boiling (just barely, and I'm pretty close to sea level) and then lower the heat and let it simmer right at temperature (just around 215°F until I get the consistency that I like.
If you get it above 235°F the sugar will begin to caramelize, this is good for candy, bad for syrup.