hello. in the past, i've been able to make good ganache cake fillings and frostings, but lately they always seem to break. so i whisk in some cold milk or cream, but then the ganache gets too runny and not terribly useful for frosting a cake.
i heat it really slowly, and when the chocolate melts it seems to be the right consistency. but the recipes i've used say to bring it up to boiling. so i do, and whammo, it breaks.
can someone tell me if there's a way to tell when it's just done? is it really necessary to heat it so much?
any help would be much appreciated!