[gymrat]

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.

[duboman]

Sometimes the paper will slip:(

[gymrat]

It still reads 0 in plain water.

[duboman]

Do you crush your own grain? If not, it's possible the supplier adjusted their mill and you got a better crush

[gymrat]

Yes I crush my own grains.

[BrewArk]

You'll never get 10.50

[dls5492]

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.

[duboman]

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.....

[klickitat jim]

Temp of sample?

"Freedom is temporary unless you are also Brave!" - Patriot

[AmandaK]

Temp of sample?

Unless it was much colder than 60, wouldn't a warmer temp result in a lower gravity reading than expected?

[mmitchem]

There is a temperature conversion chart in Ray Daniel's book Designing Great Beer

[duboman]

There is a temperature conversion chart in Ray Daniel's book Designing Great Beer

Higher temps = lower readings