The recipes don't give away all of Brewdog's secrets. There are several recipes that just don't line up very well and you just have to go with it.
Here's a few major things I've noticed:
Hop Timing:
Bittering: 60 minutes
Middle: 40 to 30 minutes
End: Seems to use a 10 minute hop stand
There are some recipes that seem to be using a measured IBU value and others are just calculated. Measured IBUs are typically 30 to 50% of calculated. With BD, their interest is in hop flavors, so trust the amounts, even if that means ignoring the calculation. Hop AA% is never stated and could account for more differences.
I’m relying on three data points I think they would pay close attention to:
1) Alcohol content (also, easy to verify)
2) Ingredient types and amounts
3) Original Gravity
Brewhouse Efficiency of 70% for most beers works, but this fluctuates. That BHE allows for 2 liters of trub. Usually it's +/- 2 points, but can go further. Higher gravity beers that are ice distilled in some part are all over the map, from 30 to 75%.
Color: This is really all over the map and seems to be the least reliable stat. Some recipes seem to total the color potential of the grains, but then don’t divide for volume. For instance, Zeitgeist shows 60 SRM, but even using the darkest versions of each ingredient, I can’t get even half of that. To me, the color targets hint at the obvious; Brewdog uses the darkest, richest and boldest grains available. That guide helps shape some unclear design decisions in the recipe book.
Yeast: To get the stated alcohol content, yeasts need to assume 90% attenuation. They really dry out these beers.
pH: This is post fermentation, NOT mash.