I'm going to back
@Sadfield here. Not because I know siding with him really confuses the hell out of him (we'll find something to have a slanging match about later), but because I do agree, the method of calculation provides a rough "reference point" to have an idea of the bitterness
your beer is going to come out. If a group of you use the same calculation you can use the figure to share recipes.
If you use the all-singing, all-dancing, calculation that produces results closer to the laboratory results you can only share your results with others using the same calculation. If anyone else says "my beer comes out too bitter" or not bitter enough, then what can you say? "Well, that's because you're not using the
X calculations, 'cos you're a dick". But who's the "dick"?
But throughout this conversation there's no mention of what is perhaps the most influential factor affecting bitterness: Hops
age! If you make no attempt to allow for age, your calculations are as good as the proverbial chocolate fireguard.
This is a snip from Beersmith of a brew I made last year (2021):
View attachment 70855
They're old hops (coming up to 2 years). Take item 13; "Goldings (Aged 18 + 4 months) (2019) [3.31 %] ". They've been aged with the Beersmith built-in calculator (but widely available elsewhere) and are deemed to be
3.3% AAUs. Another note elsewhere states "Aged @ 5C for 18 months in oxygen barrier container: AA originally 5.5%. -18C thereafter. Aging calculated as of July 2021". The first figure (18 months) is a guesstimate of the treatment before I receive them, the second (4 months) for when I slam them in a freezer.
It does require a fair bit of fiddling, knowledge of the "Hop Storage Index" (widely published) and a bit of research to develop "useable" storage condition for the time before you receive them. But if I just used what was on the packet (
5.5% AAUs) I'd be a tad disappointed about the resulting bitterness.
So, stop farting about with what "calculation" you use until you at least do things that
really make a difference!