Quick (dumb?) OG, FG question

[anje]

If I read OG and FG at the same temperature, do I have to correct for the variation from 60F? Or will they remain accurate relative to each other?

(And why, exactly, is the temperature for this not the standard 20C?)

[a10t2]

The relative offsets will be the same, so if all you want is to determine ABV, and you're using a simplified formula like

Code: [Select]

131(OG-FG), you'll be fine.

Calibration temperature depends on the instrument. I have one that's 20°C.

[mtnrockhopper]

(And why, exactly, is the temperature for this not the standard 20C?)

Probably because American manufacturing mostly uses english, not metric, measurements and hydrometers were designed for commercial brewing.

[bluesman]

Some are calibrated at 60F and others at 68F. It should be recorded on your hydrometer.