Temperature correction for specific gravity

Question

If I want to convert my specific gravity reading from one temperature to an equivalent specific gravity at 60F how do I do it?

Can you give me a correction factor for this case?

Answer 1

All temperatures are in expressed in degrees F.

correction = 1.313454 - 0.132674*F + 0.002057793*F*F - 0.000002627634*F*F*F
SG_corrected = SG + (correction * 0.001)

• http://www.primetab.com/formulas.html
• agrees with http://brewery.org/library/HydromCorr0992.html

Answer 2

jsled's answer is for when you are using a hydrometer calibrated to 59 degrees F.

The formula to correct a reading for any hydrometer calibration temperature is as follows:

cg = corrected gravity
mg = measured gravity
tr = temperature at time of reading
tc = calibration temperature of hydrometer

cg = mg * ((1.00130346 - 0.000134722124 * tr + 0.00000204052596 * tr2 - 0.00000000232820948 * tr3) / (1.00130346 - 0.000134722124 * tc + 0.00000204052596 * tc2 - 0.00000000232820948 * tc3))

Answer 3

You can also use a correction table like the one HERE.

You just add or subtract the difference from 1.000 at 60 with the temp you are at.

I hate quoting John Palmer, but he also has a table in Appendix A of Hot to brew.