Brix: The Essential Knowledge

Brix Measurement

Brix measurement and Brix meters, the essential knowledge

Brix by Density vs Brix by Refractometry

Brix measurement can be performed by refractive index as well as by density. When measuring pure sucrose content in water, the techniques will deliver the same result. However, for other samples, different results are obtained depending on the instrument (technique) used: e.g., the hydrometer, pycnometer, refractometer or digital density meter.

The accompanying table shows Brix measurement results for a variety of sample measured once with a density meter and once with a refractometer

So which method is the correct one?

In this case, both are correct! It depends on the method defined in the Standard Operating Procedure (SOP) of each laboratory. In many cases, the Brix value is just used as a check value, simpler to read than density or refractive index (e.g. 8.5 °Bx instead of nD: 1.3458,  9.1 °Bx instead of nD: 1.3465).

SampleBrix by densityBrix by refrac.Comment
20% sucrose solution20.00%20.00%Identical because only sucrose
Maltose20.02%20.34%Different because not sucrose
Fructose39.95%40.01%Different because not sucrose
Molasses43.92%42.20%Residue from sugar production, only about 50% of molasses is sucrose

Influence of Temperature

5 Ways to Measure Brix: Advantages, Disadvantages and More

Type of Instrument
 

Hydrometer
 

Hydrometer, learn how to choose it, the definition, advantages and more
Hydrometer, learn how to choose it, the definition, advantages and more

Definition / Information

A hydrometer is a glass instrument consisting of a bulbous bottom weighted with lead or steel shot and a long, narrow stem with a scale. It is used to determine the specific gravity of liquids based on buoyancy. When it comes to sugar (Brix) determination, the denser the liquid and the more sugar it contains, the higher the hydrometer will float.

When using a hydrometer for Brix measurements, make sure to have the correct calibrated type for the sample.

Main Applications
 

  • Quick checking of Brix (by density) value in quality control laboratories
  • Suitable for repeated measurements of similar kinds of samples (wine, beer, juices) due to the limited measuring range
  • Not suitable for expensive samples (large volume required).

Advantages
 

  • Simple, inexpensive
  • Quick check of an approximate value.

Disadvantages
 

  • User-dependent results
  • Takes a long time for temperature equilibration
  • Small measuring range, typically takes 20 hydrometers to cover a wide measuring range
  • Large sample volume required (140 mL to 600 mL)
  • Difficult to clean
  • Breakable.

Type of Instrument
 

Pycnometer
 

Pycnometer, learn how to choose it, the definition, advantages and more
Pycnometer, learn how to choose it, the definition, advantages and more

Definition / Information

Typically made of glass, a pycnometer is a flask of pre-defined volume used to measure the density of a liquid. It can also be used to determine the density of dispersions, solids and even gases. Pycnometers can produce very accurate results when used correctly.

Main Applications
 

  • Educational purposes in technical schools or universities
  • Production control where more precision is required
  • Analytical labs; not suitable for expensive samples as a large volume is required.

Advantages
 

  • Inexpensive
  • Directly related to the definition of density (mass divided by volume): Ideal for academia / education.

Disadvantages
 

  • User-dependent results
  • Pycnometers are calibrated for a certain temperature, e.g. 20 °C, so measurements are only valid at that temperature! The sample must be equilibrated to the calibration temperature
  • Density must be calculated
  • Typical sample volume required is 25 mL
  • High level of user training required to ensure accurate measurements
  • Measurement is time consuming (up to 25 min / sample).

Type of Instrument
 

Optical refractometer (Portable and ABBE)
 

ABBE optical Refractometer, definition, main applications, advantages and more
ABBE optical Refractometer, definition, main applications, advantages and more

Definition / Information

This is an optical device where the liquid to be measured is put onto the prism. The refractive index can be read directly from the built-in scale by looking into the refractometer.

Optical refractometers with Brix scales for the determination of sugar concentration are available for purchase. However, for more precise results, temperature must be taken into consideration, and converted using a temperature correction table.

Main Applications
 

  • Quick checks of a "rough" refractive index value, especially for Brix measurements in beverages, fruit, jam, honey and other sugar-based products
  • Testing blood and urine
  • Heat transfer fluids as ethylene and propylene glycol (antifreeze chemicals)
  • Cutting fluids and urea.

Advantages
 

  • Simple method
  • Inexpensive instrument
  • Special instruments with direct readings in Brix or salinity
  • Ideal for academia / education
  • Some Abbe refractometers can be connected to a water bath for temperature-controlled measurements.

 

 

Disadvantages
 

  • Small measuring range (requires several portable refractometers to cover a wide range)
  • No thermostating or external thermostating required
  • Operator-dependent readings, therefore limited accuracy
  • Strong light source needed to read the shadow line
  • Not suitable for GLP
  • No built-in measurement protocols.
  • More difficult calibration procedure.

Type of Instrument
 

Digital Refractometers (portable and benchtop)
 

Brix digital meters, definition, applications, advantages and more
Brix digital meters, definition, applications, advantages and more

Definition / Information

A high-resolution optical sensor measures the total reflection of a light beam emitted by a special LED light source after it hits the sample. This total reflection is converted into refractive index, Brix, HFCS or user-defined concentrations. A built-in Peltier thermostat controls the temperature of benchtop instruments.

Main Applications
 

Quality control of raw materials and final products in a wide variety of industries and segments, including:

  • Food and beverage
  • Chemicals
  • Pharmaceuticals
  • Cosmetics
  • Flavors and fragrances
  • Petroleum products.

Advantages
 

  • Easy to use
  • Small sample volume
  • Fast measurement (Portable refractometer: 2 sec. Benchtop refractometer: 15 sec.)
  • Automatic measurement means results are operator-independent
  • Dark samples can be measured
  • Built-in product management with automatic quality control (benchtop meters only)
  • Possibility to connect with other instruments for multiparameter measurements (benchtop meters only).

Disadvantages
 

  • Higher cost in comparison to hydrometers, pycnometers or optical handheld refractometers, but short return on investment.
  • Portable refractometers have no thermostating, only temperature compensation.

Type of Instrument
 

Digital Density Meter (portable and benchtop)
 

Brix measurement with density meters
Brix measurement with density meters

Definition / Information

A hollow glass tube vibrates at a certain frequency. This frequency changes when the tube is filled with the sample: The higher the mass of the sample, the lower the frequency. This frequency is measured and converted into density. A built-in Peltier thermostat precisely controls the temperature of the benchtop instrument (no water bath required).

Main Applications
 

Quality control of raw materials and final products in a wide variety of industries and segments, including:

  • Food and beverage
  • Chemicals
  • Pharmaceuticals
  • Cosmetics
  • Flavors and fragrances
  • Petrochemicals

Advantages
 

  • Easy to use
  • Small sample volume
  • Automatic measurement means results are operator-independent
  • Built-in temperature compensation (portables)
  • Built-in Peltier thermostat controls the temperature precisely (benchtop devices)
  • Offers large storage capacity for results and the possibility of connecting to PC software for data management
  • Sample can be measured directly from the sample container (portables).

Disadvantages
 

  • More expensive in comparison to hydrometers or pycnometers
  • Portable density meters have no thermostating, only temperature compensation.

 

 

Balling

Balling, the old scale to measure wort sugar content, learn more.

Degrees Plato (ºP)

Plato scale, measure sugar content during fermentation, learn more.

Oechsle

Oechsle scale, definition and more.

Baumé

Baumé scale, definition, application, equations and more

Plato, Balling, Brix, Oechsle, Baumé Tables: What Is the Difference?

Scale

Balling
(ºBalling, ºBg or ºBlg)

Information

Balling is the oldest scale and still appears on older saccharimeters, but it has been replaced by the Brix and Plato scales, mainly because the Balling scale was calibrated at 17.5°C.

Usage

Winemaking (sugar concentration in grape must)

Brewing (concentration of dissolved solids, mainly sugars)

 

 

Measure with

Density meter, pycnometer, hydrometer saccharimeter

 

 

Scale

Brix
(ºBx or %w/w)

Information

The Brix scale was created by Adolf Brix, who corrected calculation errors in the Balling tables.  

Usage

The scale most used worldwide to measure sugar concentration across different industries and samples (fruit juices, grapes, carbonated beverages, etc).

Measure with

Digital density meter, digital refractometer, pycnometer, hydrometer, manual refractometer

Scale

Plato
(ºP)

Information

The Plato scale is also an improvement on the Balling scale, and is calibrated at 20°C. The difference between Balling and Plato is about 0.05% wt/wt.

When comparing Plato with Brix, a difference in the conversion from weight percent to specific gravity is usually observed in the 5th and 6th decimal places.

Usage

Primarily used in the European brewing industry

Measure with

Digital density meter, hydrometer, manual refractometer

Conclusion: Balling, Plato and Brix scales are interchangeable and often used in practice as:

1 ºBg = 1 ºBx = 1 ºP

This is an approximation. For precise and simple measurements, the use of a benchtop digital density meter or a benchtop digital refractometer is highly recommended.

Scale

Oechsle
(ºOe)

Information

The Oechsle scale was developed to measure wine must in grape juice, and is based on the specific gravity at 15 °C or the refractive index at 20 °C.

Usage

Used to measure density of grape mainly in German-speaking countries.

 

Measure with

Digital density meter, digital refractometer, pycnometer, hydrometer, manual refractometer

Scale

Baumé
(ºB, ºBe, ºBé or Baume, with or without accent)

Information

The Baumé scale is based on the specific gravity of a sample, not the refractive index. There are different versions of the scale, for liquids more dense and less dense than water. Therefore, the Baumé value of distilled water is 0.

Usage

Used in industrial chemistry and pharma, brewing, and the winemaking industry in French-speaking countries, Spain, Australia and New Zealand.

Measure with

Digital density meter, digital refractometer, pycnometer, hydrometer, manual refractometer

 

 

3 Steps to Convert Specific Gravity into Balling, Plato or Brix

StepsExample
1 - Measure the specific gravity of your sampleResult: 1.062
2 - Take the last 2 digits of the result62
3 - Divide it by four62/4 = 15.5 ºBalling, ºP  or ºBx
This represents a sugar solution with concentration of approximately 15.5% by weight  

IMPORTANT: This is a rough approximation. However, if you need a precise result obtained via a different scale converted automatically, including automatic temperature control, a benchtop digital density meter or a benchtop digital refractometer is the perfect choice.

Brix by Density

Brix by Refractometry

FAQ

Why is Brix important?
How much sugar is in a degree Brix?
What does Brix in wine mean?

Are Brix and Plato the same?
How do you measure Brix with a digital refractometer?
How do you measure Brix with a digital density meter?