So I usually use a refractometer for my preboil and OG readings, then switch to a hydrometer for my post fermentation readings.
Yesterday I was brewing a blonde with an expected OG of 1.048 at 70% efficiency. Which I hit dead on.
I batch sparge, and while the final runnings were being pumped to my boil kettle, I was also heating the wort, and it was getting close to a boil. I stirred it well, took a coffee cup and scooped a few ounces out of the boil kettle for me preboil measurment, then let it cool to room temp while I continued heating the wort. When I came back after it had cooled completely (probably about 70F in my garage) and took my refractometer reading and I got a 1.054 reading. Looked at beersmith and realize I had just defied physics and taken more then 100% of the available sugar out my grain!
I checked the refractometer calibration with some distilled water and did another reading...same thing.
Later on, as I mentioned, the refractometer worked just as I'd expected and my OG reading was spot on.
Any ideas how I got such an errant reading? Does it have something to do with the fact the wort I sampled (even though cooled before reading) was getting near boil/hot break?
Yesterday I was brewing a blonde with an expected OG of 1.048 at 70% efficiency. Which I hit dead on.
I batch sparge, and while the final runnings were being pumped to my boil kettle, I was also heating the wort, and it was getting close to a boil. I stirred it well, took a coffee cup and scooped a few ounces out of the boil kettle for me preboil measurment, then let it cool to room temp while I continued heating the wort. When I came back after it had cooled completely (probably about 70F in my garage) and took my refractometer reading and I got a 1.054 reading. Looked at beersmith and realize I had just defied physics and taken more then 100% of the available sugar out my grain!
I checked the refractometer calibration with some distilled water and did another reading...same thing.
Later on, as I mentioned, the refractometer worked just as I'd expected and my OG reading was spot on.
Any ideas how I got such an errant reading? Does it have something to do with the fact the wort I sampled (even though cooled before reading) was getting near boil/hot break?