Ganache - It isnt setting in the fridge?

Well I have tryed this recipe https://www.instructables.com/id/E6GFU1NWXTEVYDYEQA/ and have done everything. Though, i used single cream instead of whipped cream, and i didnt put sugar syrup. I didnt think that these would make a difference (i didnt have these), so, do they? I have put it in the fridge for 15 mins, taken it out, stirred, and put back in x2 and it still isnt thickening. Does anyone know why?

Re-design8 years ago
Not enough fat.  Whipping cream is 30 -40% fat and single cream is 10 -20 % fat.  I think you don't have enough fat to make it thicken.
Carostar680 (author)  Re-design8 years ago
thanks, il look into that next time, i think i made it cold enough to make it half set, i made the balls and put back in the fridge. thanks again!
Z..8 years ago

Re-design is right.

You cannot make ganache with single cream. It is the fat content.

i would use your 'ganache' with some added milk to make some lovely hot chocolate to drink!