Gabe, make sure your measuring cup is hot/heated before pouring in your candy. Pouring into a cold/room temp measure can easily drop the temp of the candy anywhere upwards to 20 degrees, which results in what you are experiencing. You can heat the measuring cup by filling it with hot tap water or boiling water and allow this to sit for several minutes, toss the water, and the heat should also dry the cup of any residual water. If not, work fast and wipe dry with a paper towel before adding your hot candy.
I cook with wine.......sometimes I even add it to food!