- If I don't have whole wheat flour, can I just add 30 grams of additional bread flour? Also, how much of this can be made ahead? I'd like to serv...

Yep, it's fine to use all bread flour. In fact, the recipe was originally developed with just bread flour.

You can make the the dough up to the point that it rises as a dough ball in the refrigerator the night before, but you'll still need to roll out, cut and proof the doughnuts just before frying them. Proofing will take a little longer with dough that has been chilled that long (maybe an extra 15 minutes), so keep that in mind. I don't really recommend making them the day before... however if you do, you can usually refresh them a little with about 10 seconds in the microwave... they just won't be quite as good as those that were made the same day.

Hope that helps!