Brix: The essential Knowledge

Brix Measurement and Brix Meters

5 ways to measure Brix

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

The following table shows Brix measurement results of different samples measured once with a Density meter and a Refractometer

So which method is the correct one?

In this case, both are correct! It depends on the method defined in the SOP (Standard Operational Procedure) of each laboratory. In many cases, the Brix value is just used as a check value, simpler to read than a density or a 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
Fuctose39.95%40.01%Different because not sucrose
Molasses43.92%42.20%Residue from sugar production, only about 50% of molasses is sucrose

Temperature Influence

Advantages and disadvantages of the different techniques to measure Brix

Type of Instrument
 

Hydrometer
 

Hydrometer
Hydrometer

Definition / Information

A hydrometer is an instrument made of blown glass, it consists 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 of the liquid. In simple words, the heavier the liquid being tested, the higher the hydrometer will float. When it comes to sugar (Brix) determination, the denser the liquid, the more sugar it contains.

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

Main applications
 

  • Quick control of a "rough" density value, mainly for process control.
  • Suitable for the measurement of the same kind of sample (wine, beer, juices) due to the limited measuring range
  • Not suitable for expensive samples (large volume required).

Advantages
 

  • Simple, inexpensive
  • Used for a quick check of an approximate value

Disadvantages
 

  • User-dependent results
  • Takes a long time to equilibrate the temperature
  • Small measuring range (typically takes 20 hydrometers to cover a wide range)
  • Large sample volume required (140 mL to 600 mL)
  • Difficult to clean
  • Not suitable for GLP
  • Breakable

Type of Instrument
 

Pycnometer
 

Pycnometer
Pycnometer

Definition / Information

Typically made of glass, a pycnometer is a flask of a 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 be a very precise method when performed correctly

Main applications
 

  • Educational: what is density, how to measure density
  • Production control: where more precision is required
  • Analytical labs: where GLP is not required Not suitable for expensive samples (large volume 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, trustworthy measurements

Type of Instrument
 

Optical refractometer (Portable and ABBE)
 

Optical refractometer
Optical refractometer

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 can be found with Brix degrees scale for the determination of sugar concentration. However, for more precise results, the temperature must be taken into consideration, and converted using a temperature correction table.

Main applications
 

  • Quick control 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 refractometers to cover a wide range)
  • No thermostating
  • Operator dependent readings, therefore limited accuracy
  • No measurement protocol

Type of Instrument
 

Digital Refractometers (portable and benchtop)
 

Digital refractometers
Digital refractometers

Definition / Information

A high resolution optical sensor measures the total reflection of a light beam emitted by a special LED light source after hitting 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 benchtops instruments.

1: Light source
2: Prism
3: Sample
4: Optical sensor (CCD)

Main applications
 

Quality control of raw materials and final products in a wide variety of industries and segments such as: 

  • Food and beverage
  • Chemicals
  • Pharmaceutical,
  • Cosmetics
  • Flavors and fragrances
  • Petroleum

Advantages
 

Easy to use

  • Small sample volume
  • Automatic measurement means results are operator-independent
  • Built-in product management with automatic quality control
  • Built-in SOP Extension with other instruments for multiparameter measurement
  • Applicable to benchtop meters only

Disadvantages
 

  • More expensive in comparison to hydrometers, pycnometers or optical handheld refractometers
  • Portable refractometers have no thermostating, only temperature compensation.

Type of Instrument
 

Digital Density Meter (portable and benchtop)
 

Digital density meters
Digital 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 controls the temperature precisely of the benchtops instrument (no water bath required)

Main applications
 

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

  • Food and beverage
  • Chemicals
  • Pharmaceutical
  • Cosmetics
  • Flavors and fragrances
  • Petroleum

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 (benchtops)
  • Offers large storage results and the possibility to connect to PC software for data management
  • Sample can be measured directly from the sample container (portable)

Disadvantages
 

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

 

 

Balling

Balling

Degree Plato (ºP)

Degree Plato

Oechsle

Oechsle

Baumé

Baumé

Plato, Balling, Brix, Oechsle, Baumé tables: what are the differences?

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 17.5ºC

Usage

Winery (sugar concentration in grape must.

Brewery (concentration of dissolved solids, mainly sugars

Measure with

Density meter, pycnometer, hydrometer saccharimeters

Scale

Brix
(ºBr or %w/w)

Information

The Brix scale was created by Aldolf Brix, who corrected calculation errors in the Balling tables. Nowadays, modern instruments calculate mass fraction using *ICUMSA formulas.

*ICUMSA (International Commission for Uniform Methods of Sugar Analysis)

Usage

The most used scale 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 refractometers

Scale

Plato
(ºP)

Information

The Plato scale is basically an improvement from the Balling scale as well. Plato scale is calibrated at 20ºC. The difference between Balling and Plato is about 0.05% wt/wt.

When comparing Plato with Brix, they differ in their conversion from weight percent to specific gravity in the 5th and 6th digit.

Usage

Primarily used in European brewery industries

Measure with

Digital density meter, hydrometer, manual refractometers

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

1ºBg = 1ºBx = 1ºP

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

Oeschle
(ºOe)

Information

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

Usage

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

Measure with

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

Scale

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

Information

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

Usage

Used in industrial chemistry and pharma segments, brewing as well as is the winemaking industry in French speaking countries, in Spain, Austrialia and New Zeland.

Measure with

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

 

 

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 in different scales converted automatically, that also includes automatic temperature control, a benchtop digital density meter or a benchtop digital refractometer is the perfect choice.

Brix by density

Brix by refractometry

FAQ

Orange Juice
Sugar Cubes
Brix in wine

Are Brix and Plato the same? Digital meter.

how do you measure brix with a digital refractometer
how to measure brix with a digital density meter
 
 
 
 
 
 
 
Thank you for visiting www.mt.com. We have tried to optimize your experience while on the site, but we noticed that you are using an older version of a web browser. We would like to let you know that some features on the site may not be available or may not work as nicely as they would on a newer browser version. If you would like to take full advantage of the site, please update your web browser to help improve your experience while browsing www.mt.com.