missed OG by nearly 10 points

I'm trying to find out where I went wrong. Recipe was the AHS Ginger Hibiscus Saison:

11 lb 2 row Pils
.5 lb caravienne
.5 lb vienna
1 lb honey (substituted for corn sugar after speaking with people at AHS) added @ 10 minutes

(not posting hop bill or spices because I'm not sure that AHS is cool with that)

mashed at 154 for 60 minutes

Hit my pre-boil SG spot-on at 1.041

Collected ~5 gallons (uncalibrated carboy) at 1.053, target was 1.061

My guesses: either (1)the amount I collected plus what was leftover in the kettle was more than what it should've been after boil off or (2) the honey threw things off.

If your preboil gravity was right, and that reading came from the proper preboil amount of wort then something is wrong. Either you way overestimated your evaporation rate and made more beer than expected or you got a bad reading. Did you adjust for temperature when you took both gravity readings?

Brett0424 said:

If your preboil gravity was right, and that reading came from the proper preboil amount of wort then something is wrong. Either you way overestimated your evaporation rate and made more beer than expected or you got a bad reading. Did you adjust for temperature when you took both gravity readings?

Click to expand...

I may have overestimated my evaporation rate, as it is usually extremely high, but I tried to keep the burners low enough to just maintain a rolling boil.

One more testament to the value of a sight tube on your kettle. We can take gravity readings all day long but without accurate volume measurements, they don't mean much. Monitoring your volume during the boil really helps to moderate your boil-off rate. My typical boil-off rate is 1.5 gallons per hour which is 1/2 gallon every 20 minutes. My sight tube is calibrated in 1/2 gallon increments so I can glance at it every 10 minutes or so to gage how to adjust the heat.

Prosit!

Well I have a calibration rod (the dip tube from my keggle's previous life) that works just fine, but I neglected to take a reading at the end of my boil.

I really need to keep better records and decide on my actual evaporation rate.

I have noticed too, that when I substitute a liquid form of "sugar" (honey, LME) for a dry form (DME, corn sugar, etc) that I usually don't quite hit my OG, since I forget to take into account the amount of water that is in the "sugar" that I just added. I guess it is all about good record keeping and good measurements... that, or just years of experience and being able to "eyeball" it...