Need help from bakers/candy makers

I like to bake and recently, for the first time, I had to boil sugar down into a syrup to a particular temperature - between 235 and 240F. I had the saucepan on the stove and following the instructions, brought the sugar to a boil. I whipped out my handy new candy thermometer and even though the sugar was boiling away, the thermometer stopped rising at about 210F. The mixture seemed to be at the desired consistency, so probably after waiting a tad too long, I took it off the heat, as instructed and moved onto the next step. Unfortunately, the sugar hardened after about 30 seconds and I had to start over again.

This time, the thermometer wouldn't register above about 205, even though the mixture of sugar and water was at a good boil. I took it off the heat probably too soon, because I didn't want it to harden again and it never really got to be syrupy like it was supposed to.

My questions are: 1) is the thermometer broken? 2) From that description, does it sound like I was doing anything wrong?

Any help would be greatly appreciated.

 

You didn't wait long enough.

When cooking sugar in water, it can't get hotter than a boil until the water is gone. Once it's boiling, lower the heat--maintaining the boil--and watch the thermometer CLOSELY.

Now I want to make some caramels.

 

Yeah, it can take a while for that temperature to climb up to where you need it.

 

Thank you very much. I grew up with a mom who has never baked anything and on the rare occasions she cooks, tends to burn things, so I'm always afraid of overcooking. I'll do some experimenting so that the next time I try this recipe (for French macarons), I'll have the sugar part down pat.