Two beers at 1.050 with 40 IBU, one finishes at 1.020 and the other at 1.010 - the 1.010 will appear more bitter as there will be less balancing of residual sugars with bitterness.
It would seem to me that the other way - say a 1.060 and 1.040 with the same IBU and same FG wouldn't come of as being massively different in apparent bitterness.
There's no formula, but think about it.
Brew a beer at 1.040 and 20 IBU, nice balance.
If it finishes at 1.010, nice.
At 1.006, you'd probably say 'too sharp'
1.014 beefy - you'd probably say 'add more hops' (though some may say nice malty beer)
Anyway - weighed & milled, ready for the morning.
That flaked wheat didn't mill through very well, looks very untouched, maybe that's why my og was so last time.
It's the commonsense organics (millmore downs) FW, very flat unlike the torrified. Must slip through the gap.
i used to mill wheat by itself and put it through twice, hadn't thought about this stuff.
Anyway, had a big kid brown (amongst all the others) and the tap's pouring ok so all is good in the world