Need a little help crunching the numbers here...
I'm switching over from extract to all-grain, but I have one last extract kit sitting around that needs to be brewed. It's the Midwest Brewing Bourbon Barrel Ale. I have a shiny new 10-gallon kettle, so I want to try this one out as a full boil just to practice going through the motions for the upcoming AG brews.
Here's my issue: I've been running the recipe through the hopville beer calculus to adjust my hop additions for the increased utilization, but according to that I wouldn't even hit my target IBUs if I added everything.
I know bitterness isn't an exact science, but maybe someone with more familiarity running the numbers can tell me where I'm going wrong. My pre-boil gravity should be ~1.075. The full hop additions called for in the recipe (assuming a partial boil) are:
- 1 oz. of Northern Brewer pellets (8.5% AA) @ 60
- 2 oz. of Willamette pellets (4.9%) @ 30
- 2 oz. of Fuggle pellets (4.6%) @ 20
That gets me ~70 IBUs using Tinseth's equation if I added everything. The recipe calls for ~78 IBUs with a partial boil. How can I be coming out less
bitter using all of the hops and a full boil?