How to Convert Brix to Specific Gravity

Understanding Brix and specific gravity can improve your beer and wine making.

Brix and specific gravity refer to the amount of sugar in a water solution. Commonly used in beer and wine making, the amount of sugar in the unfermented wort (for beer) or must (for wine) determine the level of alcohol in the finished product. Brix is measured with a refractometer which analyzes the light passing through a sample. Specific gravity is measured with a hydrometer that is floated in the sample liquid, indicating the relative density of the liquid compared to pure water. Beer and wine recipes often specify an original (before fermentation) and final (after fermentation) gravities. If the sugar content is measured in Brix, it will be necessary to convert this figure into specific gravity.

Things You'll Need

• Brix refractometer
• Calculator (optional)

Instructions

1. Determine the degrees Brix of a solution using a Brix refractomer. For an accurate reading, the liquid should be at 68 degrees Fahrenheit or 20 degrees Celsius, since warmer liquids can hold more dissolved sugar in a given volume than cooler ones. The degrees Brix can now be converted to specific gravity using any one of the three steps below.

2. Look up the specific gravity of the solution in the table provided by the National Bureau of Standards (see References). This table also provides apparent density of the solution, and the actual weight of the sugar, in grams, dissolved in 100 milliliters of the liquid.

3. Use an online calculator (see Resources) to convert degrees Brix to specific gravity. This is probably the simplest method to follow.

4. Convert degrees Brix to specific gravity manually by using the following formula:

   Specific gravity = {Brix/(258.6-[Brix/258.2]*227.1)}+1

   Performing this calculation manually requires more effort than the previous two steps, but the formula can be entered into a programmable calculator or spreadsheet, allowing conversions to be made without the need for tables or online access.

Tips & Warnings

• The Brix scale is an updated version of an earlier one called the Balling scale. A later scale, called the Plato scale, made minor improvements to the Brix scale. These corrections affected only the fifth and sixth decimal places of the earlier versions, so for all practical purposes the terms Brix, Balling and Plato can be used interchangeably.

References

• National Bureau of Standards Table 440
• Brew Your Own - Specific Gravity

Resources

• Read this Article in Spanish
• Convert Between Brix and Specific Gravity