Yes you must leave it in the refrigerator for this ganache to be correct. I used 12 ounces of the bittersweet chocolate and 12 ounces of semi-sweet chocolate.
I made this without the coffee liquor and contrary to the other reviews, I found this ganache to be perfect. Just make sure that you leave it IN THE REFRIGERATOR during the chilling time and not just at room temperature.
The 12 oz is correct. Although it's hard to get it to set up enough to spread on the cake. Maybe I didn't wait long enough. Use semi-sweet chocolate next time if you like it sweeter!
I can not figure out if this is 12 ounces of bittersweet chocolate or just 4 ounces. I made it with 12 ounces (3 x 4 ounces) and it is super bitter. I don't know how it's supposed to taste though.