[denny]

In light of everyone's replies, I wonder why Deschutes is doing that; maybe they want a longer boil time to boost ABV.

commercial boil off rates are substantially lower than homebrewers. it might be a matter of necessity to accomplish what homebrewers can do with a 30 or 60 minutes boil.

Why even assume they do a 90 minute boil? It's a homebrew recipe.