[usingJerry Seinfeld voice] "What is the deal with first wort hop additions? The go in the kettle before the wort. They are in the kettle longer than the bittering hops. But some people say they substitute flavor and aroma additions with FWH. Who was the marketing genius that came" up with this one?"
In short, is a FWH a bittering, flavor or aroma? A combination? How much IBU does it contribute compared to a 60 minute boil?
So I have my Alt that I am brewing tomorrow. Not sure what to expect for efficiency. My 60 minute additions will have to be improvised. Measure OG and adjust hops. I like my Alt to be conservative in the hop profile.
As a reference, I looked up the Denny Milo's Alt. He uses ~30% FWH and ~70% 60 minute boil.
For hop inventory, I went with what was available at the LHBS. I got Sterling 7.2% and Hallertauer Mittelfreuh 4.0%.
Beersmith calculates FWH to be about 10% more IBU than a 60 minute boil.
So what wisdom can the reasonable and trusted brewers here tell me? Hints, help, observations, conventional wisdom?