Buying guide

Refractometers and Brix: a practical guide for sugar and juice testing

Reviewed 8 September 2026

Brix is a measure of sugar content. One degree Brix is one gram of sugar in one hundred grams of solution, so it is simply the percentage of sugar by weight. A juice at 12 Brix is 12 percent sugar; a syrup at 60 Brix is 60 percent sugar. A higher Brix reading means a sweeter, more concentrated liquid. It is the standard number in the drinks, jam, honey and fruit trades, because it turns "does this taste sweet enough?" into a figure you can specify, check and repeat.

One caution worth stating: Brix strictly measures dissolved solids as if they were all sugar. In a clean sugar solution that is exactly what they are, so the reading is a true sugar figure. In a liquid with acids or other dissolved matter, the Brix reading is very close but not a laboratory-perfect sugar assay. For juice, fruit, syrup and honey work, that is close enough to run a business on, which is what a refractometer is for.

A refractometer works on refraction, the bending of light as it passes from air into a liquid. The more sugar is dissolved, the more the light bends, and the instrument reads that bend off a scale as degrees Brix. On a hand-held optical model you place a drop of the liquid on a glass prism, close the small flap over it, hold the instrument up to the light and look through the eyepiece. You see a scale with a clear line dividing light from dark, and where that line crosses the scale is your Brix reading. Because it runs on daylight through the prism, an optical refractometer needs no batteries at all.

That is different from a digital refractometer, which reads the sample electronically and shows a number on a screen. Digital units are quicker to read and remove the small judgement of reading a line by eye, but they cost more and need power. For most juice, fruit and food work, a good optical hand refractometer is accurate, rugged and far cheaper.

This is the choice that most often goes wrong. A refractometer covers a fixed Brix range, and you must pick one that brackets what you test. Too low a range and a sweet sample runs off the top of the scale; too high and a light juice reading is cramped into the bottom where it is hard to read precisely.

• A 0 to 32 Brix range suits fruit juice, soft drinks, and checking fruit ripeness in the field. This is the everyday range for most juice and fruit work.
• Honey, heavy syrups, jam and condensed products sit much higher, often well above 60 or 70 Brix, so they need a high-range refractometer, sometimes a dedicated honey model.
• Some jobs use a very wide 0 to 90 range to cover everything in one tool, at the cost of a coarser scale.
• These are sugar refractometers. Salinity (salt), coolant and battery-acid refractometers read different scales entirely and are separate instruments.

Our stocked model is a hand refractometer with a 0 to 32 Brix scale, which covers fruit juice, soft drinks and fruit ripeness testing. If you need a higher range for honey or heavy syrup, or a salinity or coolant model, tell us and we will source it rather than sell you the wrong scale.

1. 1.Open the flap and wipe the prism clean and dry with a soft cloth.
2. 2.Place one or two drops of the sample on the prism, enough to cover it, then close the flap so the liquid spreads in a thin film with no bubbles.
3. 3.Point the instrument at a bright light or the sky and look through the eyepiece.
4. 4.Read the Brix value where the boundary line between the light and dark fields crosses the scale.
5. 5.Wipe the prism clean and dry before the next sample so it does not carry over.

Temperature affects the reading, because sugar solutions refract slightly differently as they warm or cool. Many refractometers have automatic temperature compensation (often marked ATC), which corrects for this within a normal range. If yours does not, take readings at a steady room temperature for consistency.

Calibration is quick and uses plain distilled water. Put a drop or two of distilled water on the clean prism, close the flap and look through the eyepiece: the boundary line should sit exactly on zero Brix, because pure water has no sugar. If it does not, turn the small calibration screw (usually under a cap on the top of the instrument) until the line sits on zero. Do this at the start of a testing session and whenever readings look off. It takes under a minute and keeps every reading honest.

• Juice and soft-drink makers, to hold a consistent sweetness and meet a recipe spec.
• Fruit growers and buyers, to judge ripeness and quality, since Brix rises as fruit ripens.
• Food processors making jam, sauces, syrups and condensed products, to hit a target concentration.
• Honey traders, using a high-range or honey-specific model to check sugar and grade.
• College and QC labs, as a standard, low-fuss instrument for teaching and quality checks. See our guide on setting up a college or QC laboratory.

We stock the hand-held optical 0 to 32 Brix refractometer at our Lahore shop, brand new box pack, at a published price. You can see it on the refractometers page. That range covers most juice, soft-drink and fruit work. For products outside that range, a high-range or honey refractometer, a salinity or coolant model, or a digital refractometer with a screen, message us on WhatsApp. We can often source the right instrument, and if we cannot, we will tell you honestly rather than sell you a scale that does not fit your product.