Recently drafted a "Hazy DIPA" recipe in the BrewersFriend recipe builder, with the following Fermentables:
Method: Extract, full-volume for boil 60 minutes.
Started with a volume around 8 gal., finished with probably 5.7 gal.
1LB Flaked Oats(pre-gelatinized, steeped 30)
1LB Flaked Wheat(pre-gelatinized, steeped 30)
1LB Briess White Wheat Malt(Steeped 30)
8oz Viking Wheat Malt(steeped 30)
5LB Ultralight LME(60min)
5LB Ultralight LME(late add, 15 min.)
1LB Dextrose(Late add 15 min.)
According to said recipe builder, if I attained a relatively low efficiency, I should be sitting around 1.075-1.080.
Everything went well during the brew, nothing unexpected. Took my first OG reading when it was cooled properly, and I achieved a whopping......1.060? Look again and maybe even 1.059? This is literally 15-20 points lower than I anticipated, even when factoring in a 10-15% efficiency. Even with a theoretical 0% efficiency from steeping grains, the extract and dextrose alone should have gotten me to 1.070-1.075, correct? There was less than a 1/2 gallon surplus in my fermenter, but that amount shouldn't affect it by this much. I have no explanation that I can figure, help?
I understand by doing some research that maybe I steeped the oats and wheat at the wrong temps and maybe for too long, but again, that doesn't really explain why I'm nearly 20% off my target OG. Frustrated and confused and would appreciate some guidance.
Worth noting that I think the beer will still be fantastic, and the batch isn't ruined or anything like that. Mostly just confusion and wondering how I can accurately predict this in the future.