Dopple-Alt

Has anyone tried to make a Doppel-Alt yet?

I'm in the process of formulating one now, and just want to get things straight.

So far, I've got:
~7 # Pils
~6.75# Munich
~0.25# Carafa I
~1# wheat
~1# chocolate or brumalt

Starting Gravity around 1.080

How much should I bitter this? My original alt is between 30-35 IBU. Should I go up to about 60 or 70 with such a high gravity, or should I go lower with a higher malt profile. In spite of 35 IBU on a 1.055 beer, it's mighty malty already. When I go all 'Dopple' on it, I don't want to go overboard on maltyness, but I don't want to go overhop either.

Right now, I have 42 IBU of Hallertauer and Spalter in my program, which (using the neato hop/gravity ratio graph) puts it nicely in slightly hoppy.

Is 42 IBU going to be hoppy enough for a 1.080?

*bump*

I'm planning on getting ingredients for this tonight...any last opinions would be great!!!

I think you're right about where you should be in terms of bitterness. You could go up a little, maybe to 50, but I don't think you need to. You doing any flavor/aroma additions, or just bittering?

This would also be a beer that could be decocted, if you wanted to play with some new (old) techniques.

Here's the hopping schedule:

1.50 oz Hallertauer [4.80%] (60 min) Hops 18.8 IBU
1.00 oz Hallertauer [4.80%] (45 min) Hops 11.5 IBU
1.00 oz Spalter [4.50%] (25 min) Hops 8.2 IBU
1.00 oz Spalter [4.50%] (10 min) Hops 4.3 IBU