Temperatures listed in candy instructions are for sea level. If you live at a higher altitude, it is fairly easy to adjust recipes. For every 1,000 feet/300 meters above sea level, subtract 2° F/1° C from every temperature listed.
The following temperatures are the various stages of candy (made at sea level, so if you live at a higher altitude, adjust your temperatures according to the instructions above):
Thread Stage – 215-235
Soft Ball Stage – 235-240
Firm Ball Stage – 245-250
Hard Ball Stage – 250-265
Soft Crack Stage – 270-290
Hard Crack Stage – 300-310
