are you tempering your chocolate?

if not look up tempering chocolate and see if you can find the correct temperature to work at.

This is most likely why the chocolate wont harden.

tempering chocolate is a bit dificult to get just right. i would focus on that

tempering lets the fat/oil present in the chocolate mixture crystalize as opposed to simply congealing inbetween the tiny particles of cocoa powder. this has dramatic effects on your chocolate in all kinds of ways. un-tempered chocolate will float out the fats if stored, and though chocolate tastes good either way, the texture is different.


un-tempered chocolate is just fine for melting use in the center ganache. chocolate bought from the store is allways "in temper" and if you chop it with a blade before melting it, use a steaming pan ("double boiler") or croc pot, something with slow, even heat, you should be able to maintain temper.

the homestyle way to do this is as such:
coarse chop 1/2 to 2/3rds your chocolate, melt it, dont scorch. (try not to exceede 120f.)
fine chop or use chips for the other portion
remove from heat, add remaining portion and fold chocolate until chips melt.

this works because the storebought chocolate is tempered when you buy it and will create the temper with its seed crystals and lower the temperature to the mid 90's. milk cocolate is the most forgiving for this, dark being the pickeiest.
maintain a temperature of 95f (close to your own body temperature) until you are done with the chocolate.

this process is not necissary for making ganache or any other chocolate based filling. its really just for shells, bars and bites.