I calculated the 60 min hop addition to 16-18 IBUs. 0 & Dry I winged it with a full oz.
For the German I think we used;
- Liberty, Hallertauer, partial packs like a 1/4 + 1/3 oz of leftovers to hit right at 18 IBUs
- Tettnanger, partial pack ~.80 oz at 0 min
- Perle 1oz dry leftover from a 2oz pack.
My buddy wanted to use up his partial packs so I helped him pick what hops to use at 60 so it would be on target and be done with storing partial packs of hops.
Whatever you use to bitter try to hit the target. Use software or I can calc it for you. Calculating it is pretty important for bittering. It doesn't take much to get 18 IBUs with such a small grain bill. Not to mention hallertauer can be 3.2 or 5.6 AAU. Without the calculation you can undershoot or overshoot if your not careful.
Online Recipe Calculator
Even a change in the late addition of say 1 oz of tetnanger going from 0 back up 5 min can bump your IBU 3-4 points.
No cereal mash. I used flaked corn and did a 90 min. infusion mash at 147F.
Try the corn, if you go with rice you're making Bud Light. Unless you want that...
I'd skip the dextrose, have either that or Lt DME if you hit a low SG.
Be advised with this small of a grain bill you might want to use a 5 gal mash tun or fill your tun with a few wal-mart bags that are stuffed with lots of bags. Bag in a bag trick. The thought to take up or insulate the air space.