is a provincial regulation under the Food Safety and Quality Act, 2001. It defines maple syrup as a product that:

  • is produced from the concentration and cooking of maple sap or by the dilution of maple products in potable water
  • has a minimum soluble solids content, or density, of 66% as determined by a refractometer at 20 degrees Celsius

Maple syrup density

The density of maple syrup is expressed as the percentage of dissolved, soluble solids in water. These soluble solids are composed primarily of sucrose with small amounts of fructose and glucose, plus many additional compounds that contribute to the syrup’s flavour.

Maple syrup density is measured in Brix. Brix is the percentage by weight of sugar in a pure water solution and is expressed as degrees Brix (°Brix). One-degree Brix is equivalent to one per cent sugar.

In addition to meeting the regulatory requirement described above, it is important to recognize the significant impact that density can have on the quality of maple syrup. For example, lower density syrup lacks the thicker "mouth feel" that consumers prefer and can also pose a higher risk of mould growth or fermentation. Syrup of higher density, above 68.9° Brix, may precipitate sugar crystals when stored at ambient temperatures (15°C to 30°C). This can reduce profits since more sap is required to produce the same volume of syrup.

Equipment for measuring density

There are several options available for measuring the density of maple syrup.


A hydrometer is a floatation instrument used for measuring the relative density of liquids based on buoyancy.

Hydrometers are advantageous because they:
  • are relatively inexpensive
  • are simple to use
  • have readings in °Brix
  • are readily available
There are some disadvantages to using a hydrometer:
  • Hydrometers have a limited range of measurement. Different hydrometers may be required throughout the maple syrup production process. For example, you may need to use different hydrometers to measure the density of raw sap, concentrated sap (from reverse osmosis) and the finished syrup.
  • They require a relatively large volume of sap/syrup in the sample cup.
  • They may produce inaccurate readings if they are not calibrated or are calibrated improperly.
  • They typically cannot be recalibrated by you (the user).
  • You must clean hydrometers between each sample. This can be time consuming but may cause inaccurate readings if this step is not done properly.
  • Incorrect measurement techniques can limit the hydrometer’s accuracy.
  • The readings must be adjusted for temperature of the sap or syrup. Manual temperature reading and correction is a potential source of error.
  • They are made from highly breakable glassware.


A hydrotherm is a floatation instrument that combines a hydrometer and a thermometer into one measuring unit. There are no standards for hydrotherm calibration, which means there is a greater probability of inaccuracy. Hydrotherms are not recommended unless used for approximation only.


Refractometers measure light refraction. Refraction is the bending of light passed through a sample of sap or syrup. This provides value that is displayed in degrees °Brix. Note that refractometers measure the refractive value of all dissolved substances in a sample and not just the sucrose.

Optical (or analog) refractometers

An optical refractometer uses lenses and prisms to bend light through a syrup sample to project a shadow line onto a small glass inside the instrument. The shadow line is then viewed by you (the user) through a magnifying eyepiece. The glass is marked with a degrees Brix scale and the location of the shadow line on that scale determines the Brix value.

Optical refractometers are advantageous because they:
  • Are simple to operate and only require a small sample size. An accurate measurement can be made with one or two drops of syrup spread evenly across the prism.
  • Read directly in °
  • Do not require an energy source (such as batteries). They only need natural daylight or ceiling light for use.
  • Have some models which automatically compensate for varying temperatures in the reading.
  • Are easily cleaned, which allows for quick turnaround between samples.
  • Are relatively inexpensive (compared to a digital model).
There are some disadvantages to using an optical refractometer:
  • Incorrect measurement techniques can limit the optical refractometer’s accuracy.
  • The shadow line may not always be sharp. This may make it more difficult for you to obtain a precise reading.
  • Older models may not be temperature compensated. This means that you must manually correct temperatures whenever temperatures are above or below 20°C.
  • You must be cautious to avoid scratching the lens when adding a sample or cleaning the instrument.
  • The less costly, temperature compensated optical refractometers are also less accurate when used outside a 20 to 30°C temperature range and generally are not temperature compensated for temperatures above 40°C.

Digital refractometers

Digital refractometers operate on the same principles as optical refractometers but use a battery powered light source (LED) instead of natural light, and automatically provide the Brix value.

Digital refractometers are advantageous because they:
  • Are simple to operate.
  • Record accurate measurement with one or two drops of sap or syrup.
  • Are not subjective in their readings. A digital result is not affected by the specific reading techniques you use.
  • Have automatic temperature compensation.
  • Provide rapid readings.
  • Read directly in °Brix.
  • Are easily cleaned. This results in a faster turnaround between samples.
  • Are quick and easy to calibrate with distilled water or known control solutions.
There are some disadvantages to using a digital refractometer:
  • They are generally higher in cost than the other measuring devices commonly used by maple syrup producers.
  • You must be cautious to avoid scratching the lens when adding a sample or cleaning the instrument.
  • There are common errors in technique during calibration. You must read the instructions carefully and wash your hands of sugar residue before using the instrument.
  • Despite the temperature compensation, their accuracy decreases at temperatures significantly higher than 20°C.
  • They require an energy source, such as batteries.
  • Background light can cause interference and lead to accuracy issues.

Potential sources of error

You may choose to use more than one instrument for greater confidence in the reading. Occasionally comparing density readings with equipment of a fellow producer can also alert you to potential inaccuracies.

You may also consider sending samples of your maple syrup to an accredited laboratory to compare measurement accuracy.


Temperature is the most common error associated with incorrect Brix measurement. The density of a liquid changes as the temperature changes. If your instruments are not properly corrected for temperature, this can result in an inaccurate Brix reading. Hydrometers and refractometers are most often calibrated to measure liquid density at 20°C.

Instrument calibration

It is important that you ensure all instruments are proper calibrated for use. For example, electronic refractometers require 0°Brix to be 'set' using distilled water before you start using it to measure samples.

The accuracy of the zero-set procedure should be verified using fresh calibration liquid having a known density (for example, ACER 66Brix calibration solution). Any sugary residues on your hands or fingers can cause an inaccurate zero-set.

Collecting a representative sample

The quality of your density measurements is only as good as the quality of the sample tested. Be sure to stir or mix the sap or syrup before taking the sample.

You should use clean and dry sampling equipment to avoid contaminating or diluting the sample.

Proper operation and care of a measuring instruments

To help ensure accurate sample readings, be sure to follow all manufacturer’s directions, instructions, and care/maintenance recommendations for any instrument you use.  

Additional Resources

Federal (Canada)

Requirements under O. Reg. 119/11 are in addition to federal requirements under the Food and Drugs Act or applicable sections of the Safe Food for Canadians Regulations for maple syrup sold intra-provincially. Refer directly to the Canadian Food Inspection Agency for more information about federal requirements.

Contact us

For more information about requirements under O. Reg. 119/11, please contact the Food Safety Inspection Delivery Branch at fpo.omafra@ontario.ca or call 1-877-424-1300.