GIFSQ Tools · Module 2 — Food Chemistry & Physicochemical Testing · Tool 23 of 500
Correct a refractometer reading to the standard 20 °C using the ICUMSA temperature-correction table for sucrose solutions. AOAC 932.12.
Try sample values — fills the form with the worked example below.
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Brix at 20 °C (°Bx)
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Temperature correction (°Bx)
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Observed Brix (°Bx)
Equation: Brix at 20 °C = observed Brix + correction(T, Brix), where the correction comes from the ICUMSA table below the result (linear interpolation between table rows and columns).
Method: AOAC 932.12 (solids in fruit products by refractometer); correction table from ICUMSA SPS-3 (1998), Appendix 2, for sucrose solutions measured at 589 nm. The 15 °C and 25 °C rows are the published ICUMSA values; the 10 °C and 30 °C rows are scaled from them (×2.0) and checked against the published example (Brix 65.0 at 10 °C corrects to 64.25).
Assumptions: the sample behaves like a sucrose solution; the prism and the sample are at the same temperature; the refractometer is calibrated at 20 °C.
Limitations: the table is for sucrose only — salts, acids and other solutes shift the reading, so the result is apparent Brix for mixed foods. The table covers 10–30 °C and 0–85 °Brix; outside that range, measure at 20 °C or use a temperature-controlled refractometer.
Rounding: Brix to 2 decimal places; the correction is shown to 2 decimal places.
This is a calculation aid, not a laboratory report — confirm against your accredited method before citing a value.
Method: AOAC 932.12 (solids in fruit products by refractometer); correction table from ICUMSA SPS-3 (1998), Appendix 2, for sucrose solutions measured at 589 nm. The 15 °C and 25 °C rows are the published ICUMSA values; the 10 °C and 30 °C rows are scaled from them (×2.0) and checked against the published example (Brix 65.0 at 10 °C corrects to 64.25).
Assumptions: the sample behaves like a sucrose solution; the prism and the sample are at the same temperature; the refractometer is calibrated at 20 °C.
Limitations: the table is for sucrose only — salts, acids and other solutes shift the reading, so the result is apparent Brix for mixed foods. The table covers 10–30 °C and 0–85 °Brix; outside that range, measure at 20 °C or use a temperature-controlled refractometer.
Rounding: Brix to 2 decimal places; the correction is shown to 2 decimal places.
This is a calculation aid, not a laboratory report — confirm against your accredited method before citing a value.
Worked example: A juice reads 40.0 °Brix at 25 °C. The ICUMSA correction at 25 °C and 40 °Brix is +0.40, so Brix at 20 °C = 40.0 + 0.40 = 40.40 °Bx. A syrup reading 65.0 °Brix at 10 °C corrects to 64.25 °Bx.
Enter values above to see results.
Typical Brix: orange juice 11–13, apple juice 11–13, grape juice 16–20, tomato paste 28–38, jam 65–68, honey 78–82. One °Brix is 1 g of sucrose in 100 g of solution. Tool 23 of 500 — GIFSQ
