Efficiency too high?

[iwoodcock]

So I just put my second all grain in the fermentor.
I calculated the recipe on beertools, and based on my prior experience (got a stuck mash tun) i set my efficiency at 72%
I was trying to make an IPA with an OG around 1.072
Heres my grain bill:
6 lbs. Maris Otter Pale
6 lbs. 2-Row Briees Brewers
.5 lbs. Acidulated Malt
.5 lbs. Weyermann Carapils®/Carafoam®
.75 lbs. Crystal Malt 10°L
and I added 1.35 lbs. Orange Blossom Honey
6 gallon batch

According to the calculator my OG with a 72% would be 1.072
However...I used a brand new hydrometer, calibrated it in 60 degree water, and my OG was 1.088

According to beertools my efficiency was about 89%. I feel like this is impossible, since my ten gallon rubbermaid mash tun shouldn't be above 75%.

I mashed for 60 minutes at 149, then sparged for 20 at 168, then sparged for 20 at 170.

How could my efficiency be so high? I really didn't want to make a big beer...

 

[BmillaTheBrewzilla]

Did you end up with the final amount of wort you expected? If your total volume was lower than you told beertools you were shooting for... then it would look like you got super high efficiency... when in fact you just got the same amount of sugar you were expecting, but more concentrated because of the smaller volume.

 

[iwoodcock]

No, I calculated for 20% boil off. Ended up with just under 6 gallons.