Brix, Specific Gravity, Baumé and Oechsle Explained

They all measure sugar

Juice makers, winemakers and brewers use different scales, but they all answer one question: how much sugar (or other dissolved solids) is in the liquid?

• Brix (°Bx) is grams of sugar per 100 grams of liquid. Juice at 20 °Bx has about 20 g of sugar in every 100 g. Strictly, Brix is defined for sucrose. For fruit juice, it’s a good estimate of all dissolved solids.
• Plato (°P) is the brewer’s version. It’s so close to Brix that the two can be treated as the same.
• Specific gravity (SG) compares the liquid’s density with water’s. Water is 1.000, and sugar makes a liquid heavier, so a sweet juice might read 1.083.
• Oechsle (°Oe) is used for wine in Germany, Switzerland and Austria. It’s the digits of the specific gravity after the “1.”: SG 1.083 is 83 °Oe.
• Baumé (°Bé) is used for wine in France and Australia, and for syrups. One degree Baumé is roughly 1.8 °Bx.

How the scales compare

These values come from our Brix calculator:

Brix / Plato	Specific gravity	Oechsle	Baumé	Sugar per liter
5	1.020	20	2.8	51 g
10	1.040	40	5.6	104 g
12	1.048	48	6.7	126 g
15	1.061	61	8.4	159 g
20	1.083	83	11.1	216 g
22	1.092	92	12.2	240 g
25	1.106	106	13.9	276 g

Some typical readings: ripe wine grapes are usually picked at about 20–25 °Bx, orange juice is usually around 11–12 °Bx, and most beer worts are 10–16 °P.

Refractometer or hydrometer?

A refractometer needs only a few drops and usually shows Brix. Most have automatic temperature compensation (ATC), but they’re most accurate near 20 °C. Once fermentation has started, alcohol distorts the reading. A refractometer reading taken during or after fermentation needs a correction, so use a hydrometer for those.

A hydrometer floats in a larger sample and usually shows specific gravity. It works before, during and after fermentation. It’s calibrated for one temperature, often 15.6 °C (60 °F) or 20 °C, so correct readings taken at other temperatures.

Tips for accurate readings

• Strain out pulp and let bubbles escape before measuring.
• Check your instrument in plain water. It should read 0 °Bx or SG 1.000.
• Measure at the calibration temperature, or correct for the difference.
• Write down the scale with every reading. “12” means something very different in Brix and in Baumé.

To compare a reading on any scale with all the others, use the Brix calculator.