I'm looking at a 20l batch. Though I unusually split my wort and cube hop 2x10 containers with different hops. I''ll chuck my last effort up in a bit to get the ball rolling
I'll be doing my first cube hopped IPA soon (always chilled them to preserve late hopping), thinking something like 90% Viena, 10% Biscuit and a ton of Chinook in the cube, who doesn't like an all Chinook IPA.
I agree you need some bittering hops in the boil otherwise it misses that bitterness.
My best so far was:
2kg pils
2.5g mo
900g Munich
150g pale crystal
20ibu magnum @60
50g simcoe after 10 min whirlpool for 10 mins
100g cascade cube hop
Can't remember the dry hop but i remember it didn't need much.
I'll be doing a sonar malt bill this week splitting the batch with one 10l cube getting about 100g of cascade, centennial and Chinook and the other getting mosaic Nelson and galaxy. (little nervous about the Nelson I have to say).
It will really depend on the ibu you are chasing, oboe 1050 cube only additions get pretty hefty, in the interests of keeping cube additions to 150g or less it's worthwhile considering a bittering charge, doesn't have to be a great deal but rule of thumb is about a third of total