Skimming through "Hops" by Stan H. He mentions that 50% of alpha acids are lost in the brew house and 20% is lost in fermentation and packaging. Is anyone out there planning recipes to these numbers? ie - to make a 30 IBU beer - add 100 IBUs? As an example, it is noted how a batch of HopHenge had 243 calculated IBUs, 117 measured in the fermenter, and 87 measured after packaging. I haven't seen many talk about this. What are your experiences? And - related - anyone know of any such percentages for essential oil loss, ie flavor and aroma?