Resolved a mystery today. Was really struggling to understand why the alcohol yield from my fermentations was fluctuating so much. I've spent months looking at Ph levels, mash temps, fermentation temps.
Then what I thought was a completely unrelated issue....why were the rats and mice trying to eat through sides of my empty grain hoppers all of a sudden? Turns out they weren't empty. So why is there grain in a bin that should be empty? Turns out my grain scales have been faulty for a while...which explains why alcohol yield down as each mash was short 2-3 bags of malt!