What are Brix meters?

Brix meters are handy devices used to conveniently measure the dissolved sugar content of a liquid.

They’re popular in a variety of fields. Everything from agriculture to metalwork and the food and beverage industries have a need for quick and accurate sugar content readings.

Whether you’re a seasoned orchardist, a passionate winemaker or just a home gardener, a pocket-sized Brix meter – like Optico’s handy refractometer – will quickly test the sugar levels in your fruit or crops, allowing you to assess flavour and ripeness and to adjust conditions, if necessary.

How does a Brix meter work?

Named after chemist Adolf Brix, it is a surprisingly simple device. It works by shining light through a liquid sample and measuring how much the light has been refracted.

The more sugar present in a sample, the more the light will be refracted, giving you a solid estimate of the sugar levels.

To make the meter work, you simply add a couple of drops of your sample juice to the meter’s prism, close the lid, hold the device up to a light source and look through the lens to read an internal scale. The result will appear within seconds.  

Keep in mind that sometimes other dissolved substances in the liquid can influence the results. Knowing roughly what to expect in your sample might help.

Why measure Brix?

Sugar is a big part of flavour and nutrition. Whether you’re growing fruit or brewing beer, a Brix meter can let you know when there’s a problem with taste or quality. Here are some uses for the Brix meter. 

Plants and agriculture

When it comes to agriculture and gardens, Brix meters can offer a quick insight into the health and status of your plants and soil.

The sugar content gives you an idea of the quality, flavour and ripeness of any fruits, but it can also indicate if the plants are healthy. Higher Brix readings suggest greater nutritional density, while lower readings suggest that your plants are struggling.

A Brix meter like the Optico refractometer provides a quick and convenient way to assess the condition of your plants, crops and even animal feed, isolating any issues before they can escalate.

Food and drink

Sugar levels are a big deal for food and beverage manufacturers. Sugar directly affects the taste and quality of sweet products, such as soft drinks, syrup, juice or honey.

To maintain the right flavour and consistency of their product lines, manufacturers use Brix meters to monitor the sugar levels for any deviations.

When brewing beer, fermentation can be tracked by monitoring the sugar levels. For home brewers, Brix meters can also be used to measure the specific gravity of the wort. In wine making, a Brix meter is used to test grapes for sweetness and flavour.

Other industries

Brix meters have a wide range of other uses. They can check the saltiness of a pool or fish tank, measure protein in blood, or even test how much water is mixed with coolants or oil.


All Brix meters perform the same core function, but they can have different operational ranges and some handy extra features.

Automatic temperature compensation

Temperature can have a substantial effect on Brix measurements.

If you need consistently accurate readings, you’ll need a Brix meter with automatic temperature compensation (ATC), such as the Optico refractometer.

Without temperature compensation, you’ll have to manually compensate for the difference, which can be time consuming and inconvenient. When it comes to accuracy and convenience, ATC is almost mandatory.


Every Brix meter has a little bit of inaccuracy.

If you just need general results, this might not be a huge issue. But if you want precise numbers, check the accuracy rating on your meter. The Optico refractometer, for example, has an accuracy of +/- 0.2%


Different Brix meters can have a different range of Brix values they can accurately measure. Some are general purpose with a very wide range, while others are highly specialised within a narrow field of values.

Analogue vs digital

There are two basic types of Brix meter – analogue and digital. While they both operate on the same principle of light refraction, they go about it in slightly different ways.

Analogue meters use external light sources, so they don’t require power or batteries. You look down an eyepiece and the results are displayed as a colour difference on a vertical measurement scale.

Digital meters use their own internal light source and display the results on a small screen.

So, if you want to track the progress and improvement of your crop and soil, work on your homebrew or check if your strawberries are truly sweet, you can’t go wrong with the humble Brix meter.

Previous article Fun microscope experiments for kids #3
Next article Looking at tardigrades (water bears) under the microscope