In looking at recipes, Rose often calls for “bittersweet” or “extra bittersweet” chocolate in frostings or ganache. What percentages do you generally consider these to be? For example, the Milk Chocolate Buttercream (p. 250) calls for 454 g. milk + 227g “dark chocolate, preferably extra bittersweet or bittersweet.”
Okay, in looking for another example, I noticed on the Light Whipped Ganache (p. 268 of TCB) she gives the following:
> semisweet - 53%
> extra bittersweet - 60%
And I note that on the Chocolate Cream Glaze, she mentions semisweet & bittersweet are both 53%, so these terms are interchangeable.
So I have answered my own question.
Meanwhile, I hope this rambling will prove helpful to someone else!