hard crack candy coming out too sticky I've made a few batches of hard crack candy, but so far every batch i've made has come out stickier than I'd like. by too sticky, i mean that the candies will stick to the parchment paper i store them in so hard that the two become inseparable. this happens even in the freezer. 

So far I've tried


letting the temperature go up a little higher on the candy thermometer (310-320)
adding powdered sugar after the candies have cooled down


as experiments but to no avail.
what can people recommend? is there an additive i could add to the mix?
Get another thermometer and check that your thermometer is calibrated correctly. Many of the candy thermometers from China are ± 20 C