2.5 oz. Centennial hops 10% AA - 45 minutes
1.5 oz. Centennial hops 10% AA - 30 minutes
0.5 oz. Centennial hops 10% AA - end of boil
Single step infusion mash @ 150-152 deg. F.
Collect as much wort as practical - reduce volume to approximately 5.5 gallons by extended boiling. Add extract to the wort at the beginning of the boil.
Looks very familiar to what I brewed based on the Zymurgy article. It was very good, lt was like Expedition.
Temp control is what would make it better for me today. Also consider culturing the Bell’s yest from some bottles of Amber or Pale Ale, to get the yeast profile going for you.
I might take a gravity reading before adding the extract as I am not sure you really need it. I did a 5 gallon batch of 1.105 BW with first runnings only with 31lb of grain total. so if you collect second runnings and boil a long time with the 28 lbs you’ve got there you might hit your gravity anyway.
I think Wyeast 1272 is a decent match for Bell’s yeast, if you don’t want to bother culturing. I’ve used it in an RIS that has a very similar grain bill and been quite happy with the results.
The extract is in there to reflect the recipe that was being brewed at the time. At the old brewery downtown, it was said that they could not mash enough grain to get the gravity, hence the extract to get there. There are some local brewpubs that boost the gravity with extract in the boil for the big beers.
No idea how they make Expedition today - i.e. if they use extract at all.