This is purely out of curiousity, but...
I have a go-to, dead simple chocolate ganache recipe that I make to "frost" my flourless chocolate cake (both recipes from Lora Brody's Growing Up on the Chocolate Diet.). All you do is scald one cup of heavy cream, then slowly stir in 12 oz of chopped-up bittersweet chocolate until it's thick and smooth.
This time I got distracted by a minor emergency as the cream was heating and when I got back to the stove it was already at a full boil. I immediately took it off the heat and added the chocolate. While the chocolate melted fine, it never quite mixed smoothly, it kept feeling clumpy with butterfat running in rivulets all over - even after I tried using the immersion blender to emulsify it. I ended up having to more or less strain out the chocolate mixture (which tasted just fine) and leave the extra fat behind. And when the leftover part was chilled it showed unattractive streaks of congealed white fat on top.
Anyone know why this happened? As I say, I'm just curious, I know the difference between scalding and boiling and won't (I hope!) do this again.