Refractometer Correction Calculator

How It Works

Refractometers measure the refractive index of a liquid, which correlates with sugar content (Brix). They work perfectly for pre-fermentation wort, but once alcohol is present, the reading becomes inaccurate because alcohol refracts light differently than sugar. A raw Brix reading on finished beer will read much higher than the actual sugar content. The wort correction factor (WCF) accounts for the difference between pure sucrose solutions (which refractometers are calibrated for) and wort, which contains more complex sugars — typical values are 1.03-1.06. Always take an OG reading before pitching yeast for accurate FG calculations later.