American 2-Row vs British Pale

[tstorm]

Hey all!
I just brewed a red ale twice, the only difference being that I used 12lb of British Pale in one batch, and 12lb of American 2-row in the other. My goal was to just compare the two base malts (my original recipe calls for British Pale, but American 2-row is cheaper).
Anyway, I hit an OG of 1.077 with the American 2-row, a conversion efficiency of 90%. Then I hit an OG of 1.058 with the British Pale, for a conversion efficiency of 66%.
Any ideas why the British Pale would yield so much less?

Mash schedule:
147F, 30 min
154F, 60 min
162F, 10 min
Mashout/sparge at 170F

 

[william_shakes_beer]

humm... what was the DP of the 2 row VS the british pale? I believe 2 row has more enzymes, which means the british would need a longer mash to get the same conversion.

 

[ShootsNRoots]

1.) What's the FGDB and CGDB on the malt analysis sheet for both of them?
2.) What type of crush did you use on each?
3.) Was your process consistent between the two?

There could be a plethora of reasons.

 

[tstorm]

Honestly, the malt content beats me. I don't have analysis sheets for either of them. I bought the 2-row from a friend of mine who owns a microbrewery. I need to check the bag to be sure, but I think it's Briess. I bought the British Pale from Morebeer. The crush was identical (using my homebrew shop's mill). The processes are as close as I can reasonably get - I have a homemade Ardunio mash controller that actuates my gas valve, so my mashes are very repeatable and consistent and held within a degree of the target.

A 100 minute mash should be plenty for either base malt though, correct?