Can hydrometers suddenly and without warning go wayyyy out of calibration. Today is the second time in a row I was expecting my beer to hit around 10.50 and it hit 1.066 instead. I can’t believe my efficiency suddenly took that big of a jump.
Sometimes the paper will slip:(
It still reads 0 in plain water.
Do you crush your own grain? If not, it’s possible the supplier adjusted their mill and you got a better crush
Yes I crush my own grains.
You’ll never get 10.50
Do you have access to a refractometer? I use both. If both readings are the same, then everything is cool. If one is off, then I know to calibrate. Hope this helps.
Are you hitting your volumes into the primary. With the weather changing its possible your boil off rate is changing.
Do you take a pre boil gravity? Is that consistent? If so then the change is coming from the boil forward. If the pre boil is a more efficient reading then you’re doing something better with your mash process.
Just throwing out ideas…
Temp of sample?
“Freedom is temporary unless you are also Brave!” - Patriot
Unless it was much colder than 60, wouldn’t a warmer temp result in a lower gravity reading than expected?
There is a temperature conversion chart in Ray Daniel’s book Designing Great Beer
Higher temps = lower readings