[pinchegil]

This weekend is my second brew through my herms. I brewed a Polaris Oatmeal Stout that according to beersmith should have been right at 1.075og  using 72% brewhouse efficiency (not yet really sure what the number should be).  I hit all my volumes correct and wound up with 1.092 and 24.8 brix, i used both a refractometer and hydrometer. With my grain bill I don't event think these numbers are possible.  Grain mill set to .37 500rpm.
24lb Pacific Northwest Premium 2 row
1.5 lb Carafa1
1.5 Crystal 120
.5 lb Chocolate malt
.5 lb rosted barley
1 lb flaked oats
70 min mash @156f (inlet was at 159f, grainbed was at 156f)
1hour fly sparge
90 min boil
Not really sure what happened the only thing I can think is that I might have added extra two row 24 lbs requires two buckets so perhaps I added wrong but I didn't start drinking until after mash in, even so it would have to be 4 lbs and 80+ efficiency to reach this number.  Now I am hoping that my 3 litre wlp 001 starter will be enough.  Anyone have any ideas on what else I could have done wrong, would loading it with unfermentables raise the OG.  Im not complaining but I need to figure this out. Could this be something with HERMS? I just built the system, and had never used one before.

[natebriscoe]

A 1 hour fly sparge can easily get you over 80% efficiency.
What batch size?

[kramerog]

Sounds like you may have done something right to get an efficiency of 88%, not something wrong.  I would expect a HERM system to give a better efficiency than a single infusion cooler system. 

Since the OG is so high, plan on re-aerating the wort about 12-24 hours after the initial pitch.

[a10t2]

The first thing that jumped out at me was the large discrepancy between hydrometer and refractometer readings, even after a wort correction. When were they last calibrated?

You're also using brewhouse efficiency, which BeerSmith defines using the fermenter volume IIRC. Could be comparing apples and oranges there.

[pinchegil]

It was a 11 gallon total batch (10gal + 1 gal trub).  13 gals pre-boil I have come to the conclusion that I added 4 extra pounds  I use a hanging scale and probably screwed up the tare.

[pinchegil]

I must have misread the brix It should be near 22, my refractometer also has gravity, and it was just above 1.09

[brewinhard]

Were your volumes post-boil all correct?

[pinchegil]

I was a about a quart low on final volume using stamped kettle markings

[69franx]

Was that quart low at end of boil, or at end of chilling/into fermenter. Cooling will condense and you will lose a little volume there as well, think Beersmith estimates at 4%.

[HoosierBrew]

I have come to the conclusion that I added 4 extra pounds  I use a hanging scale and probably screwed up the tare.

If so, that would be the biggest culprit.    Being a quart low on wort at post boil (thereby concentrating it) contributed maybe 4 points-ish given your OG measurement , but extra grain definitely speaks for itself.

[brewinhard]

I have come to the conclusion that I added 4 extra pounds  I use a hanging scale and probably screwed up the tare.

If so, that would be the biggest culprit.    Being a quart low on wort at post boil (thereby concentrating it) contributed maybe 4 points-ish given your OG measurement , but extra grain definitely speaks for itself.

Definitely a good pairing for an average than higher efficiency and OG.

[pinchegil]

I don't have an issue, I am just trying to calibrate my HERMS.  I'm think it will be a good beer, I used 1oz CTZ at 60, 3 oz polaris at 15, 3 oz polaris @ 5, and 3 oz polaris 15 min whirlpool @ 140. Hoping for a good Chocolate Oatmeal Stout with a slight mint finish