Hi all. I have been brewing since the beginning of the year with 4 batches under me (last two in primary right now). I've been reading HBT almost daily for almost a year, and have read Palmer's book, How to Brew.
My first two beers finished stuck at 1.020 according to my hydrometer. Both started around 1.050 and used Nottingham yeast. I questioned the accuracy of my hydrometer at the time and even took a reading on tap water which read about 1.000 so I thought I was good.
I also have a refractometer (ATC) so the last 2 or 3 batches I took readings with both instruments. One was 1.054 / 13.1 Brix, the other 1.051 / 12.8 brix. I am using a correction factor of 0.9872 and I recalibrate it on every batch.
After these beers were in the primary for 5 and 3 days respectively I took readings with the hydrometer and refractometer again. The hydrometer readings were 1.022 and 1.023. The younger beer had competed fermentation to the point of no bubbles in the airlock (glass carboy) so I was pissed that my yeast quit on me again. The refractometer readings at this time were 7.4 and 7.5 Brix.
Again I question the accuracy of my hydrometer. I ran these numbers through the calculators from beer smith, morebeer, and brewzor - all with similar results. They all say my current gravity should be about 1.014 and 1.016 which is what I expect from the yeasts in these two batches (Nottingham and Saffbrew S-33).
Do you think my hydrometer is inaccurate in this range? After 4 batches with the same result, all in a pretty good temperature controlled room (65-70 degrees).
Thanks for your input!