Ha! Opened Pandora's Box!...

[Airspeed]

OK, so yesterday I went into a local brew store and saw a thermometer/hydrometer combo that had a colorful scale that seemed easier to read than the one I normally use. So I spent the $13.

Today, using the very same sample of the word I boiled this morning, I got this from the new hydrometer:

76 deg F with 1.042 gravity

Then I did what I should never have done - I dunked in the older hydrometer:

74 deg F with 1.048 gravity

I know the difference between before and after fermenting is more important than the absolute value, and I know which instrument took what reading, but my confidence in the preciseness of these things is now severely shaken...

 

[j1n]

check them both with plain water and see which one is off.

 

[Mexibilly]

Plain water, distilled even, should read 1.000

 

[GilaMinumBeer]

"I knew a Pandora once. Never got to open her box tho'."

Hydrometers can be off. j1n has provided the method to check.

 

[unionrdr]

Also read in water at the temp on the paper inside the thing. It should be 60F or 66F.

 

[imasickboy]

I have four hydrometers, and all four read differently.

I use the one that is closest to 1.000 in distilled water @ 60 degrees. The other three just hang around and look pretty.