Brewing Efficiency Problem - Math not working out

For the last couple of brews, I have been having major problems hitting my target OG. Today I was attempting to brew a Tripel. Recipe was:

11 lbs Gambrinus Pale
0.5 lbs Rahr wheat
0.5 lbs Briess Bonlander
1 lb raw orange blossom honey

According to Qbrew, for a 5-gallon recipe this should give an OG of 1.073.

I had targeted a preboil volume of 8.25 gallons and ended up with 8 gallons into the pot. Refractometer reading was 10.6, which is around 1.043. My calculated boiloff rate is 1.625 gal/hr, and this was a 90-minute boil, so I should have ended up with 5.5 gallons after the boil, and I always figure on a 10% loss due to break material, yeast cake in primary and secondary, etc.

The 1.043 reading was before I added the honey, and according to the calculators, boiling 8 gallons of 1.043 wort down to 5.5 gallons should give a reading of 1.063. The pound of honey should bump that up close to the 1.073 I was hoping for.

I ended up after the boil with a wort reading of 14.6 Brix, checked with the hydrometer and got 1.060 at somewhere around 80-85 degrees, so probably 1.062-63 after temperature correction. The volume into the 6.5 gallon carboy is definitely 5.5 gallons or less. So what the heck happened? Did the honey just disappear?

The 1.073 from the recipe was assuming 75% efficiency. According to the efficiency calculators, the grain I used to achieve 8 gallons of wort at 1.043 gives me 77% efficiency. So if my efficiency is on target, my volume is on target, how am I getting readings that are so far off? 1.063 is not Tripel starting gravity. Most of my lagers this winter I was within a point of my goal, and if I was off I was normally overshooting my gravity. Is it possible that both my refractometer and hydrometer are off? Could the hot weather be affecting things?

The "around 80-85 degrees" and "5.5 gal or less" remarks lead me to think that you're not getting very accurate measurements, which is critical for determining efficiency. How sure are you that you started with exactly 8 gallons? Did you adjust the volume measurements for temperature? I suggest reading this- http://braukaiser.com/wiki/index.php/Troubleshooting_Brewhouse_Efficiency

If you ended up with 5.5 gal after losses to break material etc, then you need to use the actual post boil volume for calculating how much the wort has concentrated, not the 5.5 gal. For example, if you lost ~1/2 gal, then the actual end volume was closer to 6 gal, and 8 gal of 1.043 wort boiled down to 6 gal is only 1.058.

It's also possible that the honey hadn't fully mixed with the rest of the wort when you took your reading. When did you add it and how did you incorporate it with the wort?

Okay, so maybe it was 7.92 gallons. 9.5" of water in my brew kettle at 75F is 8 gallons, with the 8 gallons being measured according to the markings in my 5 gallon pot. Fill it to 16 quarts, dump water into kettle, and repeat. Thermal expansion of water at 170F (when preboil measurement was made) is around 1%, so 7.92 instead of 8.

Honey was added 10 minutes after the boil began, so it should have fully mixed. Today was a hot day, so I was only able to cool my wort to 90F, and I didn't bother taking the temperature of the sample I diverted into my hydrometer tube. Air temperature was somewhere in the high 70s to low 80s and the sample sat for a while before I was able to test it.

I have no clue how to measure the actual postboil volume. Displacement of the wort chiller prevents accurately measuring and flameout, and I've never measured the volume of break material after transfer to primary since that varies sometimes from batch to batch. Even with break loss I normally hit within one point.

And now that I reread the Braukaiser I do realize that I forgot to weight the pale malt. I bought a 20 pound bag, used 9 pounds last week and assumed that the remainder weighed 11 pounds. I'll have to be better about that next time, but if it was underweight I doubt it was more than a few ounces. Certainly not enough to undershoot my target by 15%.

You seem to be assuming 55 ppppg for honey. That would require it to be about 120% pure sugar....

I'm just using what Qbrew defaults to, which is 1.042 for honey. It shows 1 pound of honey as adding 8 points to a 5 gallon batch, or 7 points to a 6 gallon batch. But I guess that's another variable that I really don't have an accurate measurement for.