Glossary
Specific gravity
The density of wort or beer relative to water, where water is 1.000 — the standard way brewers track how much dissolved sugar a liquid contains.
Also called sg, gravity.
Sugar is denser than water, so a sweeter wort reads higher. A typical bitter starts around 1.038 and finishes around 1.010; the gap is the sugar the yeast consumed.
Gravity is usually read with a hydrometer, which floats at a depth determined by density, or a refractometer, which measures how much the liquid bends light. Both need correcting for temperature, and a refractometer needs a further correction once alcohol is present because ethanol bends light differently from water.
Related
- Original gravity — The reading taken before fermentation.
- Final gravity — The reading taken after fermentation.
- Degrees Plato — The equivalent scale used across much of Europe.
- Hydrometer — The instrument most commonly used to read it.
More vocabulary
ABV · ABW · Alcohol unit · Alkalinity · Alpha acid · Apparent attenuation · Attenuation · Beta acid · Cohumulone · Degrees Lovibond
See every term on the glossary index.
Last reviewed 2026-08-16.