I'm going to do a 5 gallon Brewer's Best Cream Ale extract kit with instructions for a 2.5 gallon boil as follows:
3.3 lb. Extra Light LME - 55 min boil
2.0 lb. Pilsen DME -- 15 min boil
1 lb. Corn sugar -- 15 min boil
1.25 oz. Willamette bittering hops 5.5% AA -- 55 min
1 oz. Willamette aroma hops 5.5% AA -- 10 min
I have the ability & desire to do a full boil with outdoor burner & wort chiller, so I want to do full boil. However, there is a note in the instructions indicating "IBUs will be higher with a larger boil." So, I've checked tastybrew.com's recipe calculator & come up with 37 IBUs (instructions show 16-18).
Can someone help me adjust the recipe (or the instructions) to more closely match the anticipated IBUs? Using the calculator I don't get in the range of IBUs until I get down to .5 oz bittering hops. Or should I just follow the partial boil instructions?