I just brewed a batch using whole hops exclusively for the first time. From a 10.75 gal start I ended a 60 min boil with 7.5 gal in the fermenter. My efficiency was a lousy 59%. Just how much of the wort do these little beauties suck up? To be fair I did use 8 oz of hops in the batch. Still though, I have been reliably in the 75-80% range for the last 3 brews. Is this to be expected or should I make some adjustments?

What a scare. When I cleaned my kettle I found that the suction on my dip tube ended early. There was a little over half a gallon of liquid still in the kettle. This boosted my efficiency up to 66%. Not great but I'll take it.

Whole hops can suck up quite a bit. Before adjusting for hop-kettle losses, my extract efficiencies average about 80%. But accounting for these losses, I get only 71% efficiency into the carboy. The difference is the kettle to carboy efficiency of about 89%. For a beer with a lot of hops, this is closer to 80-85%. For a low-hop beer, I get 90-95%.